Techniques for achieving high hardness EPDM formulations.There is considerable interest in replacing some thermoplastics thermoplastics, materials that soften or melt when heated and harden when cooled. Thermoplastic polymers consist of long polymer molecules that are not linked to each other. i.e., have no cross-links. and metals with high hardness elastomeric components. Crosslinked elastomeric parts provide vibration isolation Vibration isolation is the process of isolating an object, such as a piece of equipment, from the source of vibrations. Despite construction distinctions the essence of all vibration isolation systems are similar. , low noise transmission, good sealing capabilities and low deformation deformation /de·for·ma·tion/ (de?for-ma´shun) 1. in dysmorphology, a type of structural defect characterized by the abnormal form or position of a body part, caused by a nondisruptive mechanical force. 2. over a wide temperature range. In extruded profiles, high hardness EPDM EPDM Ethylene-Propylene-Diene-Monomer EPDM Enterprise Product Data Management EPDM Ethylene Propylene Dimonomer (industrial/commercial piping/plumbing components) EPDM Engineering Product Data Management compounds are often used to replace metal or thermoplastic A polymer material that turns to liquid when heated and becomes solid when cooled. There are more than 40 types of thermoplastics, including acrylic, polypropylene, polycarbonate and polyethylene. inserts to provide some rigidity rigidity /ri·gid·i·ty/ (ri-jid´i-te) inflexibility or stiffness. clasp-knife rigidity . Such compounds can be co-extruded and continuously cured along with softer compounds. The traditional way to achieve high hardness, above 90 durometer Du`rom´e`ter n. 1. An instrument for measuring the degree of hardness; especially, an instrument for testing the relative hardness of steel rails and the like. A, requires the use of high levels of reinforcing fillers such as low particle size Particle size, also called grain size, refers to the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials. carbon blacks and precipitated silicas, along with low levels of plasticizer plas·ti·ciz·er n. Any of various substances added to plastics or other materials to make or keep them soft or pliable. plasticizer or -ciser Noun . However, such compounds are difficult to mix and process due to the high compound viscosities. EPDM is often the elastomer elastomer (ĭlăs`təmər), substance having to some extent the elastic properties of natural rubber. The term is sometimes used technically to distinguish synthetic rubbers and rubberlike plastics from natural rubber. of choice for heat and weather resistant applications where oil resistance is not critical. This article will therefore focus on techniques for achieving high hardness with EPDM compounds. Historically, EPDM elastomers have been manufactured using vanadium vanadium (vənā`dēəm), metallic chemical element; symbol V; at. no. 23; at. wt. 50.9415; m.p. about 1,890°C;; b.p. 3,380°C;; sp. gr. about 6 at 20°C;; valence +2, +3, +4, or +5. Vanadium is a soft, ductile, silver-grey metal. based Ziegler-Natta (Z-N) catalyst systems. These vanadium based Z-N catalyst systems are known to have product and process limitations (refs. 1-3). One of these limitations is the ability to produce very high ethylene ethylene (ĕth`əlēn') or ethene (ĕth`ēn), H2C=CH2, a gaseous unsaturated hydrocarbon. It is the simplest alkene. , high crystalline Like a crystal. It implies a uniform structure of molecules in all dimensions. For example, phase change technology, widely used for rewritable optical discs, uses crystalline spots (bits) to reflect the laser beam. Amorphous, non-crystalline bits do not reflect light. products. Typically, the highest level of ethylene achievable with Z-N systems is around 80% by weight. Commercially available EPDM elastomers range in ethylene content from 40 to around 80 weight %. These elastomers produced in this ethylene range vary from completely amorphous Unorganized or vague. A lack of structure. For example, the amorphous state of a spot on a rewritable optical disc means that the laser beam will not be reflected from it, which is in contrast to a crystalline state which will reflect light. See crystalline. to semi-crystalline products. Metallocene catalyst Metallocene catalyst A transition-metal atom sandwiched between ring structures having a well-defined single catalytic site and well-understood molecular structure used to produce uniform polyolefins with unique structures and physical properties. based technology allows EPDM products to be produced well above the typical ethylene levels achieved with vanadium based Z-N catalyst systems. The crystallinity Crystallinity refers to the degree of structural order in a solid. In a crystal, the atoms or molecules are arranged in a regular, periodic manner. In a gas, the relative positions of the atoms or molecules are completely random. of EPDM elastomer is a function of the ethylene content. Figure 1 shows the dependence of crystallinity on ethylene content. It is also well known that for a given EPDM compound, the compound hardness is directly related to the crystallinity of the base EPDM elastomer. The high crystallinity in EPDM provides another means of achieving high hardness. [FIGURE 1 OMITTED] Other techniques to achieve higher hardness have been used in the rubber industry for some time. Crosslinking thermoset A polymer-based liquid or powder that becomes solid when heated, placed under pressure, treated with a chemical or via radiation. The curing process creates a chemical bond that, unlike a thermoplastic, prevents the material from being remelted. See thermoplastic. resins resins, n.pl complex, insoluble, sticky substances secreted by plants. Used as astringents, antimicrobials, and antiinflammatories, and are burned as incense. Can cause oral ulcers and epidermal irritations. and non-crosslinking thermoplastic resins Noun 1. thermoplastic resin - a material that softens when heated and hardens again when cooled thermoplastic plastic - generic name for certain synthetic or semisynthetic materials that can be molded or extruded into objects or films or filaments or used have been used extensively to increase hardness of rubber compounds. These are generally added both as pro-cess acids and as hardness improvement agents. The most common additives used include high density polyethylene High-density polyethylene (HDPE) is a polyethylene thermoplastic made from petroleum. It takes 1.75 kilograms of petroleum (in terms of energy and raw materials) to make one kilogram of HDPE. , cyclized natural rubber, high styrene sty·rene n. A colorless oily liquid from which polystyrenes, plastics, and synthetic rubber are produced. Also called vinylbenzene. SBR SBR - Spectral Band Replication resin resin, any of a class of amorphous solids or semisolids. Resins are found in nature and are chiefly of vegetable origin. They are typically light yellow to dark brown in color; tasteless; odorless or faintly aromatic; translucent or transparent; brittle, fracturing (HS-SBR) and Novolac phenol-formaldehyde (PF) resins. The use of high sulfur sulfur or sulphur (sŭl`fər), nonmetallic chemical element; symbol S; at. no. 16; at. wt. 32.06; m.p. 112.8°C; (rhombic), 119.0°C; (monoclinic), about 120°C; (amorphous); b.p. 444.674°C;; sp. gr. at 20°C;, 2. crosslinking to form semi-ebonite type compounds is also used with highly unsaturated unsaturated /un·sat·u·rat·ed/ (un-sach´ur-at?ed) 1. not holding all of a solute which can be held in solution by the solvent. 2. denoting compounds in which two or more atoms are united by double or triple bonds. diene Dienes are hydrocarbons which contain two double bonds. Dienes are intermediate between alkenes and polyenes. Classes Dienes can be divided into three classes:
Experimental Materials All materials used in this study were commercially available products. Some of the HC-EPDM polymers were produced in the pilot plant facility using metallocene catalyst based technology as experimental grades. Compounding and testing All compounds were mixed in a laboratory internal mixer mixer, either of two electronic devices in which two or more signals are combined. In the type of mixer used in radio receivers, radar receivers, and similar systems, a signal is translated upward or downward in frequency. using standard upside Upside The potential dollar amount by which the market or a stock could rise. Notes: This is basically an educated guess on how high a stock could go in the near future. See also: Bull, Downside down mix procedure and dumped dump v. dumped, dump·ing, dumps v.tr. 1. To release or throw down in a large mass. 2. a. around 140[degrees]C. The curatives were added on a two-roll mill. Standard ASTM ASTM abbr. American Society for Testing and Materials or ISO (1) See ISO speed. (2) (International Organization for Standardization, Geneva, Switzerland, www.iso.ch) An organization that sets international standards, founded in 1946. The U.S. member body is ANSI. test procedures were used for compound and physical testing. For polymer characterization A rather long and fancy word for analyzing a system or process and measuring its "characteristics." For example, a Web characterization would yield the number of current sites on the Web, types of sites, annual growth, etc. , some internal DuPont Dupont, DuPont, Du Pont, or du Pont may refer to: Companies
The development, characterization and some applications of HC-EPDM were discussed in detail by Walton, et al (ref. 4). Highly crystalline EPDM in very high hardness compounds (40-50 durometer D) The initial work was carried out using EPDM grades containing varying levels of ethylene from 70 to 93 weight % and Mooney Mooney is family name, which is probably predominantly derived from the Irish Ó Maonaigh. It can also be spelled Moony, Meaney, Mauney, Moon, Money. The word can refer to: Companies
Meaney spelling A typical high hardness weather-strip weath·er-strip tr.v. weath·er-stripped, weath·er-strip·ping, weath·er-strips To fit or equip with weather stripping. test formulation formulation /for·mu·la·tion/ (for?mu-la´shun) the act or product of formulating. American Law Institute Formulation (table 2) was used in the initial evaluations. The compounds were mixed in a laboratory internal mixer. The black incorporation time (BIT) is defined as the time required to incorporate the filler fill·er 1 n. One that fills, as: a. Something added to augment weight or size or fill space. b. A composition, especially a semisolid that hardens on drying, used to fill pores, cracks, or holes in wood, plaster, during the mixing operation. The BIT is our an indication of cycle time, mixing efficiency and filler dispersion dispersion, in chemistry dispersion, in chemistry, mixture in which fine particles of one substance are scattered throughout another substance. A dispersion is classed as a suspension, colloid, or solution. level. This study clearly established the relationship between mixing behavior and the compound stiffness (modulus See modulo. and hardness). Increasing EPDM crystallinity results in higher compound modulus and poor mixing efficiency (figure 2). [FIGURE 2 OMITTED] The polymer characterization (temperature vs. complex viscosity) using a rubber process analyzer analyzer /ana·ly·zer/ (an´ah-li?zer) 1. a Nicol prism attached to a polarizing apparatus which extinguishes the ray of light polarized by the polarizer. 2. is another way to differentiate polymers (figure 3). Higher crystalline polymers show a rapid reduction in the viscosity above the melting region. Below this critical temperature the polymer remains "non-molten" or too stiff and inhibits mixing operation. Semi-crystalline EPDM (SC-EPDM) containing 70% ethylene gives a linear curve over the range of temperature (above its Tc of 36[degrees]C), confirming faster initiation of mixing. [FIGURE 3 OMITTED] While HC-EPDM provides a good means of achieving high hardness, it is difficult to mix highly crystalline polymers in conventional rubber processing equipment. Hence, the use of HC-EPDM alone makes it somewhat less practical. HC-EPDM in blends Blends of the different HC-EPDM products (ethylene content from 75-93%) with a commercial semi-crystalline EPDM containing 70% ethylene were evaluated. The semi-crystalline EPDM was used primarily to initiate the mixing operation. The semi-crystalline product provides high shear forces shear force Force acting on a substance in a direction perpendicular to the extension of the substance, as for example the pressure of air along the front of an airplane wing. Shear forces often result in shear strain. in the mixer during the filler incorporation phase and develops fast temperature rise in the mixing chamber, thus facilitating the melting and mixing of HC-EPDM. A 70/30 blend of semi-crystalline to HC-EPDM blend was found to be the optimum blend ratio for ease of processing balance of physical properties (ref. 3). Test results for compounds containing blends are summarized in table 3. These blends provide fast mixing times with high vulcanizate modulus and hardness. Thus providing practical recipes for high stiffness EPDM formulations. Two surprising observations for such blends were improvement in compression set and the low temperature properties over a polymer with the blend composition. Typically, one would expect the compression set and low temperature properties to be negatively impacted with increase in the ethylene content of the blend. This behavior might be explained by the morphology morphology In biology, the study of the size, shape, and structure of organisms in relation to some principle or generalization. Whereas anatomy describes the structure of organisms, morphology explains the shapes and arrangement of parts of organisms in terms of such of the compound. The two polymers may not be intimately mixed to form a continuous single phase. The two polymers appear to form two distinct discontinuous discontinuous /dis·con·tin·u·ous/ (dis?kon-tin´u-us) 1. interrupted; intermittent; marked by breaks. 2. discrete; separate. 3. lacking logical order or coherence. co-vulcanized phases. The high crystalline phase is most likely dispersed dis·perse v. dis·persed, dis·pers·ing, dis·pers·es v.tr. 1. a. To drive off or scatter in different directions: The police dispersed the crowd. b. like a filler in a continuous main polymer matrix, which is made up of the semi-crystalline product. The mechanical properties of the vulcanizate, such as hardness, modulus and tensile strength tensile strength Ratio of the maximum load a material can support without fracture when being stretched to the original area of a cross section of the material. When stresses less than the tensile strength are removed, a material completely or partially returns to its , are likely to be influenced by the discontinuous crystalline phase, and the low temperature properties and compression set properties are influenced by the continuous semi-crystalline phase. The use of amorphous EPDM/HC-EPDM blends is discussed in detail by Daniel Daniel, book of the Bible Daniel, book of the Bible. It combines "court" tales, perhaps originating from the 6th cent. B.C., and a series of apocalyptic visions arising from the time of the Maccabean emergency (167–164 B.C. (ref. 5). This concept has also been used in the development of new EPDM products and discussed by Meiske, et al (ref. 6). Use of thermoplastic and thermosetting resins Noun 1. thermosetting resin - a material that hardens when heated and cannot be remolded thermosetting compositions plastic - generic name for certain synthetic or semisynthetic materials that can be molded or extruded into objects or films or filaments or The use of thermoplastic and various thermosetting resins as additives to increase compound stiffness and hardness is commonly practiced in the rubber industry. This part of the study compared the use of various resins both in semi-crystalline and in blends of SC-EPDM with HC-EPDM. The following additives were first evaluated in 70% ethylene containing semi-crystalline EPDM (SC-EPDM). * Highly crystalline ethylene octene Oc´tene n. 1. (Chem.) Same as Octylene. copolymer copolymer: see polymer. ; * high styrene (83%) containing styrene butadiene butadiene (by  t'ədī`ēn), colorless, gaseous hydrocarbon. There are two structural isomers of butadiene; they differ in the location of the two carbon-carbon double bonds in the copolymer
(HS-SBR);* phenol phenol (fē`nōl), C6H5OH, a colorless, crystalline solid that melts at about 41°C;, boils at 182°C;, and is soluble in ethanol and ether and somewhat soluble in water. formaldehyde formaldehyde (fôrmăl`dəhīd'), HCHO, the simplest aldehyde. It melts at −92°C;, boils at −21°C;, and is soluble in water, alcohol, and ether; at STP, it is a flammable, poisonous, colorless gas with a suffocating novolac resin (PF) with a hexa-methylene tetramine tetramine 2,2,2,-tetramine (trientine) and 2,3,2-tetramine are copper chelating agents used to remove copper in chronic hepatobiliary disease, particularly Bedlington terrier copper-associated hepatopathy. (HMT HMT Her Majesty's Treasury (UK) HMT Hazardous Materials Table (49 CFR 172.101) HMT Health Management Technology (magazine) HMT Higher Mother Tongue HMT Hindustan Machine Tools Ltd. ) crosslinker; and * liquid polybutadiene Polybutadiene is a synthetic rubber that has a high resistance to wear and is used especially in the manufacture of tires. It has also been used to coat or encapsulate electronic assemblies, offering extremely high electrical resistivity. with high sulfur. The test recipes and the test results are summarized in table 4. A 70/30 blend of semi-crystalline EPDM with highly crystalline EPDM was already established as the optimum blend for ease of processing and desired stiffness characteristics. The same test recipes were repeated with the 70/30 blends of the semi-crystalline EPDM with two HC-EPDM grades with 85% and 93% ethylene, respectively. The results are summarized in tables 5 and 6. The viscosity of compounds containing the 93% ethylene-based HC-EPDM was difficult to measure at 100[degrees]C. This may lead to processing problems at normal process conditions. Results and discussions Compound viscosity The compound viscosity measured at 100[degrees]C (ML 1+4 @ 100[degrees]C) is a good indicator of processability of a given compound under normal processing conditions. In this study, only the use of the polyolefin polyolefin synthetic material used for surgical sutures, e.g. in polyethylene and polypropylene sutures. resin and the low molecular weight liquid polybutadiene rubber (Liq.BR) lowered the compound viscosity of the base compound. The same trend was observed with the blends containing the HC-EPDM. Hardness and modulus of vulcanizates The thermoplastic resin did not show any enhancement of the hardness or the modulus. While the crosslinkable thermoset materials showed improvement in both hardness and modulus of the compound, the Liq.BR and the PF resin showed the largest increase in the hardness and modulus values. The HS-SBR resin showed only moderate increase (figures 4 and 5). [FIGURES 4-5 OMITTED] Vulcanizate stiffness at elevated temperatures The modulus values of the various vulcanizates at 10% strain were measured between room temperature and 100[degrees]C. The compound without any additive additive In foods, any of various chemical substances added to produce desirable effects. Additives include such substances as artificial or natural colourings and flavourings; stabilizers, emulsifiers, and thickeners; preservatives and humectants (moisture-retainers); and (all EPDM compound) and the compound with the thermoplastic polyolefin additive showed low modulus at room temperature and lost over 50% of the modulus at 100[degrees]C. The compounds containing the HS-SBR, PF resin and the Liq.BR showed high initial modulus at room temperature. While the PF and Liq.BR compounds lost the modulus gradually as the temperature was increased, the HS-SBR compound lost its modulus rather rapidly. The modulus of HS-SBR containing compound was almost the same as the compound with no additives (figures 6 and 7). [FIGURES 6-7 OMITTED] It would appear that the HS-SBR resin does not have adequate unsaturation un·sat·u·rat·ed adj. 1. Of or relating to an organic compound, especially a fatty acid, containing one or more double or triple bonds between the carbon atoms. 2. Capable of dissolving more of a solute at a given temperature. to develop a high degree of crosslinking. The thermoplastic polystyrene polystyrene (pŏl'ēstī`rēn), widely used plastic; it is a polymer of styrene. Polystyrene is a colorless, transparent thermoplastic that softens slightly above 100°C; (212°F;) and becomes a viscous liquid at around 185°C; component in HS-SBR, while providing good hardness and modulus at room temperature, loses its stiffness at 100[degrees]C due to its low softening softening /sof·ten·ing/ (sof´en-ing) malacia. softening a change of consistency, with loss of firmness or hardness. point. Thermoplastic polyolefin resins These are highly compatible with EPDM and provide only limited, if any, enhancement in the hardness and stiffness to these compounds. Due to the fully saturated saturated /sat·u·rat·ed/ (sach´ah-rat?ed) 1. denoting a chemical compound that has only single bonds and no double or triple bonds between atoms. 2. unable to hold in solution any more of a given substance. nature of the polyolefin resins, they do not take part in the sulfur crosslinking process and remain as the unvulcanized Adj. 1. unvulcanized - (used of rubber) not subjected to the process of vulcanization unvulcanised unprocessed - not altered from an original or natural state; "unprocessed commodities" phase. Hence, these compounds show a tendency to soften at elevated temperatures. High styrene SBR resins (HS-SBR) Unlike the polyolefin resins, the HS-SBR resins contain some unsaturations on the polymer backbone and can be crosslinked with sulfur based curing systems. However, due to the polar nature of the HS-SBR resins, they only have limited compatibility with EPDM and may remain as a separate domain in the vulcanizate. The high styrene content also makes it somewhat thermoplastic in nature, and thermal deformation occurs at elevated temperature. Phenol-formaldehyde novolac resins Novolac resins are among the oldest class of thermosetting resins used in the plastics industry (ref. 8). The crosslinking mechanisms of novolac resins are well established. The PF resin is crosslinked using a methylene methylene /meth·y·lene/ (meth?i-len) the bivalent hydrocarbon radical —CH2— or CH2dbond. meth·yl·ene n. donor The party conferring a power. One who makes a gift. One who creates a trust. donor n. a person or entity making a gift or donation. DONOR. He who makes a gift. (q.v.) such as HMT to form a multi-dimensional network resulting in an extremely hard product. Despite the limited compatibility of a highly polar novolac resin with EPDM, the resulting compound shows good resistance to thermal deformation at elevated temperatures. The high polarity (1) The direction of charged particles, which may determine the binary status of a bit. (2) In micrographics, the change in the light to dark relationship of an image when copies are made. of the novolac reduces the tendency of the EPDM curatives to bloom bloom 1. the general appearance of the surface. In carcass meat it is the glistening, transparent effect and the gentle pink color that gives a good bloom to the carcass. It is the result of proper tissue hydration coupled with the correct proportions of fat, connective tissue and due to the solubility solubility Degree to which a substance dissolves in a solvent to make a solution (usually expressed as grams of solute per litre of solvent). Solubility of one fluid (liquid or gas) in another may be complete (totally miscible; e.g. of the curative curative /cur·a·tive/ (kur´ah-tiv) tending to overcome disease and promote recovery. cu·ra·tive adj. 1. Serving or tending to cure. 2. residues in the PF resin. PF resins also act as process aids during the fabrication fabrication (fab´rikā´sh  n),n the construction or making of a restoration. stages. Liquid polybutadiene resins The use of liquid BR with high sulfur (5-6 phr) is a novel method of applying "old technology" in EPDM. The use of high sulfur in SBR and NR to produce semi-ebonite type compounds is well known (ref. 7). The use of high sulfur to produce such compounds is not feasible with EPDM due to low levels of unsaturation, particularly the lack of backbone unsaturation in EPDM. The liquid BR produces a semi-ebonite type system within the EPDM network. The BR is relatively compatible with EPDM and co-vulcanizes with the EPDM with the same sulfur based cure system. The low molecular weight of the liquid BR acts as a plasticizer during processing and produces easy processing compounds. The liquid BR based system also gives low thermal deformation. The high level of unsaturation in the BR helps to consume the curative and reduce curative bloom. As with any high sulfur based cure system, the vulcanization vulcanization (vŭl'kənəzā`shən), treatment of rubber to give it certain qualities, e.g., strength, elasticity, and resistance to solvents, and to render it impervious to moderate heat and cold. showed somewhat higher compression set values. Conclusions The use of HC-EPDM provides an excellent means of attaining high hardness EPDM compounds. EPDM grades containing ethylene above 75% weight are difficult to process on their own in conventional rubber processing equipment. Thus it is difficult to achieve practical high hardness recipes with EPDM grades containing greater than 75 wt. % ethylene. The results of this study show that a 70/30 blend of a semi-crystalline grade with HC-EPDM provides excellent balance of the following properties: * Faster mixing times with good filler dispersion; * easier processing on the mills; * good retention of stiffness (hardness and modulus) over a wide temperature range; * good compression set; * good low temperature behavior; and * reduction in compound viscosity. The data in this study suggests that a unique compound morphology Noun 1. compound morphology - the part of grammar that deals with combinations of simple words into compound words morphology - studies of the rules for forming admissible words is achieved when blending HC-EPDM with regular grades of EPDM. The HC-EPDM appears to form a discontinuous phase in the semi crystalline EPDM matrix, yet both co-vulcanize together. The modulus hardness and the compound stiffness come from the HC-EPDM component while the desirable low temperature and compression set are achieved via the forming crystalline EPDM component. Further enhancement in compound hardness can be achieved using high styrene SBR, novolac phenol formaldehyde resins The earliest commercial synthetic resin is based on a Phenol formaldehyde resin (PF) with the commercial name Bakelite, and is formed from an elimination reaction of phenol with formaldehyde. or low molecular weight liquid polybutadiene. The novolac and liquid BR polybutadiene also provide good resistance to deformation over a wide temperature range. The combination of high crystalline EPDM/EPDM blends with crosslinking resins can be used to provide practical, easy processing high hardness formulations.
Table 1 - polymer properties
Grade Wt. % Tc % ML1+4
ethylene ([degrees]C) * ENB @ 125[degrees]C
IP 4725 70 -- 5 25
Controll 78 -- 5.5 28
Experimental 75 67 2 17
IP NDR4820 85 80 4 20
IP NDR4920 93 101 4 14
* Temperature of crystallization
Table 2 - test recipe for evaluation of HC-EPDM
and blends
Material Phr
EPDM 100
FEF-N550 black 130
High viscosity paraffinic oil 45
Ground CaC[O.sub.3] 40
Zinc oxide 5
Stearic acid 3
PEG 4000 3
Styrenic resin 20
Polyethylene wax 7
CaO 9
Sulfur 3
ZnEPC 1
CBS 80% 2
TMTD 80% 0.5
TDEC 70% 0.2
Vulkalent E/C 80% 0.5
Table 3 - vulcanizate properties of HC-EPDM
blends in test recipe
Polymer IP Control HC- HC-
4725P EPDM EPDM
Ethylene content, (%) 70 78 85 93
ENB content, (%) 5 5.5 4 4
Polymer blend, %
IP 4725 100 70 70
Control 100
NDR 4820 (85% C2) 30
NDR 4920 (93% C2) 30
Black incorporation time
BIT, seconds 160 260 180 170
Vulcanizate properties
(ISO 37 T2, initial)
Tensile strength, Mpa 10.4 9.4 10.3 11.7
Elongation, % 237 183 217 185
Modulus at 10%, Mpa 3.4 4.6 4.5 5
Hardness, durometer D 39 44 44 46
(1 sec., initial)
Compression set
(ISO 815B)
70 hrs. at 23[degrees]C, % set 47 59 54 48
22 hrs., at 100[degrees]C, % set 72 79 79 79
Temperature retraction
(ISO 2921)
TR10, [degrees]C -22 -17 -24 -15
Table 4 - effect of resins in semi-crystalline EPDM
None EO HS-SBR
IP 4725P (70%C2) 100 100 100
E-8402 15
High styrene resin 15
Liquid BR
PF resin 86%
Zinc oxide 5 5 5
Stearic acid 1 1 1
N550 70 70 70
Atomite 60 60 60
Paraffinic oil 15 15 15
ZnDBC 0.5 0.5 0.5
TBBS 1.5 1.5 1.5
DPTT 0.5 0.5 0.5
TMTD 0.5 0.5 0.5
Vulkalent E/C 1 1 1
Sulfur 1.5 1.5 1.5
HMT 80%
Total 256.5 271.5 271.5
Specific gravity 1.301 1.269 1.283
Compound properties
Mooney viscosity, ML 1+4, 100[degrees]C 61 49 62
Mooney scorch @ 125[degrees]C
Minimum viscosity @ 125[degrees]C 21.9 16.1 22.5
Minutes to 5 pt. Rise 12.5 15.9 21.2
Minutes to 10 pt. Rise 13.9 17.6 24.1
MDR @ 160[degrees]C, 0.5[degrees] arc
(30 min. cht)
[M.sub.L] (dN.m) 1.7 1.3 1.6
[M.sub.H] (dN.m) 30.1 20.8 30.7
[t.sub.s1] (minutes) 1.9 2.3 2.3
[t.sub.s2] (minutes) 2.2 2.8 2.9
[t.sub.c50] (minutes) 4.2 4.5 5.6
[t.sub.c95] (minutes) 12.6 8.8 16.4
Tan delta @ [M.sub.L] 1.018 1.032 0.943
Tan delta @ [M.sub.H] 0.305 0.306 0.082
Cure rate ([M.sub.H][-M.sub.L]/
[t.sub.90][-t.sub.2]) 3.9 4.1 3.1
Vulcanizate properties
Press cured: [t.sub.c95]+3 min./
160[degrees]C
Physical properties (@ 23[degrees]C)
Stress at 10%, strain MPa 1.99 2.27 3.55
Stress at 50% strain, MPa 3.75 3.66 5.14
Stress at 100% strain, MPa 5.88 5.05 6.69
Stress at 300% strain, MPa 14.21 11.3 11.68
Tensile strength, MPa 14.27 13.61 12.03
Elongation, % 300 376 320
Hardness, durometer D 37 37 43
Physical properties (@ 100[degrees]C)
Stress at 10% strain, MPa 0.9355 0.6317 0.7755
Stress at 25% strain, MPa 1.843 1.418 1.266
Stress at 50% strain, MPa 2.804 2.113 1.865
Stress at 100% strain, MPa 4.847 3.412 6.166
Tensile strength, MPa 7.314 6.255 6.371
Elongation, % 161 205 227
Compression set, method B (pellets
cured MDR [t.sub.c95] +15 min.)
22h./70[degrees]C 14 32 37
22h./100[degrees]C 36 46 33
Low temperature properties by DSC,
[degrees]C
Tg -40 -36 -38
Tc 22 23 23
Tm 36 36 38
Change in properties after aging
Aged in air 70h./125[degrees]C
Modulus at 100% elongation, MPa 10.22 9.33 9.37
% modulus change 73.8 84.8 40.1
Tensile strength, MPa 15.47 15.75 14.84
% tensile change 8.4 15.7 23.4
Elongation, % 175 189 198
% Elongation change -41.7 -49.7 -38.2
LiqBR PF resin
IP 4725P (70%C2) 100 100
E-8402
High styrene resin
Liquid BR 12
PF resin 86% 12
Zinc oxide 5 5
Stearic acid 1 1
N550 70 70
Atomite 60 60
Paraffinic oil 15 15
ZnDBC 0.5 0.5
TBBS 0.5 1.5
DPTT 0.5 0.5
TMTD 0.5 0.5
Vulkalent E/C 1 1
Sulfur 6 1.5
HMT 80% 2
Total 273 270.5
Specific gravity 1.283 1.294
Compound properties
Mooney viscosity, ML 1+4, 100[degrees]C 44 76
Mooney scorch @ 125[degrees]C
Minimum viscosity @ 125[degrees]C 15.8 30.5
Minutes to 5 pt. Rise 11.2 6.3
Minutes to 10 pt. Rise 12.6 7.4
MDR @ 160[degrees]C, 0.5[degrees] arc
(30 min. cht)
[M.sub.L] (dN.m) 1.4 2.3
[M.sub.H] (dN.m) 51.5 49.1
[t.sub.s1] (minutes) 1.5 0.5
[t.sub.s2] (minutes) 1.7 0.6
[t.sub.c50] (minutes) 3.5 2.7
[t.sub.c95] (minutes) 15.7 14.5
Tan delta @ [M.sub.L] 0.963 0.979
Tan delta @ [M.sub.H] 0.142 0.275
Cure rate ([M.sub.H][-M.sub.L]/
[t.sub.90][-t.sub.2]) 6.1 4.9
Vulcanizate properties
Press cured: [t.sub.c95]+3 min./
160[degrees]C
Physical properties (@ 23[degrees]C)
Stress at 10%, strain MPa 3.76 4.05
Stress at 50% strain, MPa 5.7 5.16
Stress at 100% strain, MPa 8.43 6.49
Stress at 300% strain, MPa - 10.89
Tensile strength, MPa 15.13 10.99
Elongation, % 213 307
Hardness, durometer D 46 45
Physical properties (@ 100[degrees]C)
Stress at 10% strain, MPa 2.115 2.381
Stress at 25% strain, MPa 3.255 3.042
Stress at 50% strain, MPa 4.415 3.778
Stress at 100% strain, MPa 6.992 5.115
Tensile strength, MPa 7.673 5.488
Elongation, % 109 111
Compression set, method B (pellets
cured MDR [t.sub.c95] +15 min.)
22h./70[degrees]C 24 30
22h./100[degrees]C 53 64
Low temperature properties by DSC,
[degrees]C
Tg -37 -38
Tc 22 22
Tm 37 38
Change in properties after aging
Aged in air 70h./125[degrees]C
Modulus at 100% elongation, MPa 11.17 9.55
% modulus change 32.5 47.1
Tensile strength, MPa 13.91 14.48
% tensile change -8.1 31.8
Elongation, % 141 186
% Elongation change -34.1 -39.3
Table 5 - effect of resins in HC-EPDM (85% C2) blends
None EO HS-SBR
IP 4725P 70 70 70
NDR-4820 (85% C2) 30 30 30
E-8402 15
High styrene resin 15
Liquid BR
PF resin 86%
Zinc oxide 5 5 5
Stearic acid 1 1 1
N550 70 70 70
Ground CaC[0.sub.3] 60 60 60
Paraffinic oil 15 15 15
ZnDBC 0.5 0.5 0.5
TBBS 1.5 1.5 1.5
DPTT 0.5 0.5 0.5
TMTD 0.5 0.5 0.5
Vulkalent E/C 1 1 1
Sulfur 1.5 1.5 1.5
HMT 80%
Total 256.5 271.5 271.5
Specific gravity 1.304 1.271 1.286
Compound properties
Mooney viscosity, ML 1+4, 100[degrees]C 57 45 57
Mooney scorch @ 125[degrees]C
Minimum viscosity @ 125[degrees]C 20 15 21
Minutes to 5 pt. Rise 13.8 15.9 22.7
Minutes to 10 pt. Rise 15.5 17.8 25.9
MDR @ 160[degrees]C, 0.5[degrees] arc
(30 min. cht.)
[M.sub.L] (dN.m) 1.6 1.1 1.5
[M.sub.H] (dN.m) 31.8 20.5 31.2
[t.sub.s1] (minutes) 1.9 2.2 2.4
[t.sub.s2] (minutes) 2.2 2.7 3.0
[t.sub.c50] (minutes) 4.3 4.3 5.5
[t.sub.c95] (minutes) 14.2 8.6 14.0
Tan delta @ [M.sub.L] 1.032 1.105 0.980
Tan delta @ [M.sub.H] 0.308 0.346 0.140
Cure rate ([M.sub.H][-M.sub.L]/
[t.sub.90][-t.sub.2]) 3.8 4.3 3.8
Vulcanizate properties
Press cured: [t.sub.c95]+3 min./
160[degrees]C
Physical properties (@ 23[degrees]C)
Stress at 10% elongation, MPa 3.11 3.17 4.6
Stress at 50% elongation, MPa 4.97 4.82 6.28
Stress at 100% elongation, MPa 7.19 6.30 7.82
Stress at 300% elongation, MPa 15.40 12.40 12.67
Tensile strength, MPa 15.86 14.56 12.92
Elongation, % 313 372 326
Hardness, durometer D 43 43 48
Physical properties (@ 100[degrees]C)
Stress at 10% strain, MPa 0.9174 0.6896 0.8239
Stress at 50% strain, MPa 2.631 1.895 2.294
Stress at 100% strain, MPa 4.686 3.239 3.616
Tensile strength, MPa 7.089 6.229 6.903
Elongation, % 154.7 208.8 222.3
Compression set, method B (pellets cured
MDR [t.sub.c95] +15 min.)
22h./70[degrees]C 32 49 56
22h./100[degrees]C 35 48 35
Low temperature properties by DSC,
[degrees]C
Tg -37 -37 -37
Tc 43 40 47
Tm 65 64 71
Change in properties after aging
Aged in air 70h./125[degrees]C
Modulus at 100% elongation, MPa 11.75 10.83 11.27
% modulus change 63.4 71.9 44.1
Tensile strength, MPa 17.73 18.30 15.15
% tensile change 11.8 25.7 17.3
Elongation, % 191 224 174
% elongation change -38.9 -39.8 -46.7
LiqBR PF resin
IP 4725P 70 70
NDR-4820 (85% C2) 30 30
E-8402
High styrene resin
Liquid BR 12
PF resin 86% 12
Zinc oxide 5 5
Stearic acid 1 1
N550 70 70
Ground CaC[0.sub.3] 60 60
Paraffinic oil 15 15
ZnDBC 0.5 0.5
TBBS 1.5 1.5
DPTT 0.5 0.5
TMTD 0.5 0.5
Vulkalent E/C 1 1
Sulfur 6 1.5
HMT 80% 2
Total 273 270.5
Specific gravity 1.285 1.296
Compound properties
Mooney viscosity, ML 1+4, 100[degrees]C 38 70
Mooney scorch @ 125[degrees]C
Minimum viscosity @ 125[degrees]C 14 28
Minutes to 5 pt. Rise 11.8 7.6
Minutes to 10 pt. Rise 13.5 8.5
MDR @ 160[degrees]C, 0.5[degrees] arc
(30 min. cht.)
[M.sub.L] (dN.m) 1.1 2.3
[M.sub.H] (dN.m) 56.1 38.2
[t.sub.s1] (minutes) 1.5 0.4
[t.sub.s2] (minutes) 1.7 0.6
[t.sub.c50] (minutes) 3.6 2.2
[t.sub.c95] (minutes) 16.8 15.7
Tan delta @ [M.sub.L] 1.044 1.044
Tan delta @ [M.sub.H] 0.088 0.478
Cure rate ([M.sub.H][-M.sub.L]/
[t.sub.90][-t.sub.2]) 5.8 4.0
Vulcanizate properties
Press cured: [t.sub.c95]+3 min./
160[degrees]C
Physical properties (@ 23[degrees]C)
Stress at 10% elongation, MPa 4.76 5.36
Stress at 50% elongation, MPa 6.89 6.36
Stress at 100% elongation, MPa 9.70 7.58
Stress at 300% elongation, MPa 0.00 0.00
Tensile strength, MPa 16.11 11.92
Elongation, % 217 292
Hardness, durometer D 51 51
Physical properties (@ 100[degrees]C)
Stress at 10% strain, MPa 2.21 2.599
Stress at 50% strain, MPa 4.351 3.616
Stress at 100% strain, MPa 4.844
Tensile strength, MPa 5.895 6.743
Elongation, % 78.37 167.9
Compression set, method B (pellets cured
MDR [t.sub.c95] +15 min.)
22h./70[degrees]C 40 51
22h./100[degrees]C 54 65
Low temperature properties by DSC,
[degrees]C
Tg -36 -36
Tc 45 47
Tm 68 71
Change in properties after aging
Aged in air 70h./125[degrees]C
Modulus at 100% elongation, MPa 12.45 10.87
% modulus change 28.4 43.4
Tensile strength, MPa 14.96 15.65
% tensile change -7.1 31.3
Elongation, % 137 176
% elongation change -36.7 -39.5
Table 6 - effect of resins in HC-EPDM (93% C2) blends
None EO HS-SBR
IP 4725P 70 70 70
IP NDR-4920 (93% C2) 30 30 30
E-8402 15
High styrene resin 15
Liquid BR
PF resin 86%
Zinc oxide 5 5 5
Stearic acid 1 1 1
N550 70 70 70
Ground CaC[0.sub.3] 60 60 60
Paraffinic oil 15 15 15
ZnDBC 0.5 0.5 0.5
TBBS 1.5 1.5 1.5
DPTT 0.5 0.5 0.5
TMTD 0.5 0.5 0.5
Vulkalent E/C 1 1 1
Sulfur 1.5 1.5 1.5
HMT 80%
Total 256.5 271.5 271.5
Compound properties
Mooney scorch @ 125[degrees]C
Minimum viscosity @ 125[degrees]C 19 13 18
Minutes to 5 pt. Rise 14.5 18.3 23.5
Minutes to 10 pt. Rise 16.3 21.0 27.1
MDR @ 160[degrees]C, 0.5[degrees] arc
(30 min. cht.)
[M.sub.L] (dN.m) 1.5 1.1 1.4
[M.sub.H] (dN.m) 32.5 21.6 32.1
[t.sub.s1] (minutes) 2.0 2.3 2.4
[t.sub.s2] (minutes) 2.4 2.8 3.0
[t.sub.c50] (minutes) 4.9 4.7 5.8
[t.sub.c90] (minutes) 9.6 8.0 12.4
[t.sub.c95] (minutes) 12.6 9.8 16.1
Tan delta @ [M.sub.L] 1.020 1.113 0.979
Tan delta @ [M.sub.H] 0.282 0.319 0.092
Cure rate ([M.sub.H] [-M.sub.L]/
[t.sub.90][-t.sub.2]) 4.3 3.9 3.3
Vulcanizate properties
Physical properties (@ rt)
Press cured: [t.sub.c95]+3 min./
160[degrees]C
Modulus at 50% elongation, MPa 5.77 5.39 7.06
Modulus at 100% elongation, MPa 8.25 7.11 8.93
Modulus at 200% elongation, MPa 12.64 10.89 12.49
Modulus at 300% elongation, MPa 15.42 14.05 0.00
Tensile strength, MPa 15.98 15.93 14.56
Elongation, % 303 365 298
Hardness, durometer D 46 45 49
Compression set, method B (pellets cured
MDR [t.sub.c95] +15 min.)
22h./70[degrees]C 45 56 50
70h./100[degrees]C 37 48 57
Change in properties after aging
Aged in air 70h./125[degrees]C)
Modulus at 100% elongation, MPa 12.76 11.59 11.97
% modulus change 54.7 63.0 34.0
Tensile strength, MPa 18.34 18.89 16.98
% tensile change 14.8 18.6 16.6
Elongation, % 178 214 193
% elongation change -41.3 -41.2 -35.3
LiqBR PF resin
IP 4725P 70 70
IP NDR-4920 (93% C2) 30 30
E-8402
High styrene resin
Liquid BR 12
PF resin 86% 12
Zinc oxide 5 5
Stearic acid 1 1
N550 70 70
Ground CaC[0.sub.3] 60 60
Paraffinic oil 15 15
ZnDBC 0.5 0.5
TBBS 1.5 1.5
DPTT 0.5 0.5
TMTD 0.5 0.5
Vulkalent E/C 1 1
Sulfur 6 1.5
HMT 80% 2
Total 273 270.5
Compound properties
Mooney scorch @ 125[degrees]C
Minimum viscosity @ 125[degrees]C 12 26
Minutes to 5 pt. Rise 11.6 9.5
Minutes to 10 pt. Rise 13.4 10.5
MDR @ 160[degrees]C, 0.5[degrees] arc
(30 min. cht.)
[M.sub.L] (dN.m) 1.1 2.3
[M.sub.H] (dN.m) 57.9 41.6
[t.sub.s1] (minutes) 1.4 0.5
[t.sub.s2] (minutes) 1.6 0.8
[t.sub.c50] (minutes) 3.6 2.6
[t.sub.c90] (minutes) 12.2 9.1
[t.sub.c95] (minutes) 17.9 12.4
Tan delta @ [M.sub.L] 1.048 1.115
Tan delta @ [M.sub.H] 0.076 0.387
Cure rate ([M.sub.H] [-M.sub.L]/
[t.sub.90][-t.sub.2]) 5.4 4.7
Vulcanizate properties
Physical properties (@ rt)
Press cured: [t.sub.c95]+3 min./
160[degrees]C
Modulus at 50% elongation, MPa 7.81 6.69
Modulus at 100% elongation, MPa 11.15 8.49
Modulus at 200% elongation, MPa 16.64 11.18
Modulus at 300% elongation, MPa 0.00 12.24
Tensile strength, MPa 17.51 12.69
Elongation, % 216 306
Hardness, durometer D 53 51
Compression set, method B (pellets cured
MDR [t.sub.c95] +15 min.)
22h./70[degrees]C 63 54
70h./100[degrees]C 43 67
Change in properties after aging
Aged in air 70h./125[degrees]C)
Modulus at 100% elongation, MPa 14.17 12.39
% modulus change 21.7 45.9
Tensile strength, MPa 17.61 17.82
% tensile change 0.6 40.4
Elongation, % 155 181
% elongation change -28.5 -41.0
References (1.) Swogger. K. W. "Molecular control and unique polymer structure creating new opportunities through Insite technology," METCON METCON Control of Meteorological Information '94, May, 1994. (2.) Snyder Snyder, city (1990 pop. 12,195), seat of Scurry co., NW Tex., in a prairie and mesquite region; inc. 1907. Oil production is the city's main industry; natural gas is also refined and processed. , R., Brann Brann can refer to:
emanating from or pertaining to Europe. European bat lyssavirus see lyssavirus. European beech tree fagussylvaticus. European blastomycosis see cryptococcosis. Rubber Journal, European EPDM Conference, Brussels Brussels (brŭ`səlz), Fr. Bruxelles, Du. Brussel, city and region (1995 pop. 948,122), 63 sq mi (162 sq km), capital of Belgium, central Belgium, on the Senne River and at the junction of the Charleroi-Brussels and Willebroek , May, 2000. (3.) Parikh, D., Laughner, M., Edmondson Edmondson is a surname, and may refer to
natural philosophy, physics - the science of matter and energy and their interactions; "his favorite subject was physics" behavior of ethylene elastomers," proceedings of the 154th Rubber Division, American Chemical Society The American Chemical Society (ACS) is a learned society (professional association) based in the United States that supports scientific inquiry in the field of chemistry. Founded in 1876 at New York University, the ACS currently has over 160,000 members at all degree-levels and in meeting, Sept. 1998. (4.) K. Walton, M. Hughes and D. Parikh. "A new class of ethylene propylene-diene terpolymers produced from constrained con·strain tr.v. con·strained, con·strain·ing, con·strains 1. To compel by physical, moral, or circumstantial force; oblige: felt constrained to object. See Synonyms at force. 2. geometry geometry [Gr.,=earth measuring], branch of mathematics concerned with the properties of and relationships between points, lines, planes, and figures and with generalizations of these concepts. metallocene catalysts," 158th Rubber Division, American Chemical Society meeting, Oct. 2000. (5.) C. Daniel, "Introduction of novel higher crystallinity EPDM polymers--applications review in the rubber industry," presented at C.C.G.--2001, l'Odyssee du Caoutchouc caoutchouc (kou`ch  k), natural rubber obtained as a latex from various tropical plants, e.g., the Pará rubber tree. It is much more elastic than balata or gutta-percha. , Lyon LyonEnglish Lyons City (pop., 1999: city, 445,452; metro. area, 1,348,932), east-central France. Located at the confluence of the Rhône and Saône rivers, it was founded as the Roman military colony Lugdunum in 43 BC (see , France, May 16-17, 2001. (6.) Larry Lar´ry n. 1. Same as Lorry, or Lorrie. Meiske, Deepak Parikh and John Pillow, "Stretching the EPDM product design: Dual composition metallocene EPDM, " presented at the Rubber Division, ACS (Asynchronous Communications Server) See network access server. , Cleveland, OH, October 2001. (7.) J.A. Brydson. "Plastics materials," published by Butterwoth & Co., 1970. (8.) B. Goulding. "Polymers and resins--their chemistry and chemical engineering," published by D. Van Nostrand, 1959. This article is based on a paper given at the October 2001 meeting of the Rubber Division. |
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