A new curative for ethylene acrylic elastomers.Vamac ethylene ethylene (ĕth`əlēn') or ethene (ĕth`ēn), H2C=CH2, a gaseous unsaturated hydrocarbon. It is the simplest alkene. acrylic acrylic, artificial fiber made from a special group of vinyl compounds, primarily acrylonitrile. Acrylic fibers are thermoplastic (i.e., soften when heated, reharden upon cooling), have low moisture regain, are low in density, and can be made into bulky fabrics. elastomers (AEM AEM Applied and Environmental Microbiology (journal) AEM Association of Equipment Manufacturers AEM Academic Emergency Medicine (journal) AEM Agnico-Eagle Mines Limited AEM Advanced Engine Management ) are designed to withstand high and low temperatures and aggressive new automotive fluids in under hood automotive applications such as seals, gaskets, ducts, hoses, boots and dampers. The most frequently used 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. system used in AEM compounds is a combination of HMDC HMDC Harvard-MIT Data Center HMDC Hackensack Meadowlands Development Commission (hexamethylenediamine Hexamethylenediamine or 1,6-hexanediamine is a diamine with a hexamethylene hydrocarbon chain and amine functional groups at each end. It has a strong amine odor, similar to piperidine. Hexamethylenediamine is produced from adiponitrile. carbamate carbamate /car·ba·mate/ (kahr´bah-mat) any ester of carbamic acid. car·ba·mate n. A salt or ester of carbamic acid. ) with DOTG (di-o-tolylguanidine) or DPG DPG diphosphoglycerate. (diphenylguanidine). HMDC breaks down into HMDA HMDA Hexamethylene Diamine (chemistry) HMDA Hitchhiker Motorized Door Assembly HMDA High Mobility DGM Assemblage HMDA Home Mortgage Disclosure Act of 1974 (hexamethylenediamine) and carbon dioxide carbon dioxide, chemical compound, CO2, a colorless, odorless, tasteless gas that is about one and one-half times as dense as air under ordinary conditions of temperature and pressure. (C[O.sub.2]) when it is exposed to heat and/or and/or conj. Used to indicate that either or both of the items connected by it are involved. Usage Note: And/or is widely used in legal and business writing. moisture. During the high temperatures seen in the cure process, the HMDC is converted to HMDA, which is the active curing agent for the AEM (figure 1a). The active curing agent (HMDA) for the AEM is the same whether starting with HMDC or HMDA, the only difference is that HMDC liberates both the HMDA and C[O.sub.2]. The HMDC 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. is the second highest cost component of AEM compounds. The mechanism for curing AEM with HMDA is shown in figure 1b (rels. 1-6). [FIGURE 1 OMITTED] The Advancure is based on patented curing technology from DuPont Dupont, DuPont, Du Pont, or du Pont may refer to: Companies
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. technology from Chem Technologies. Advancure is a 47% active liquid concentrate of hexamethylenediamine (HMDA) absorbed on 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. highly dispersible silica silica or silicon dioxide, chemical compound, SiO2. It is insoluble in water, slightly soluble in alkalies, and soluble in dilute hydrofluoric acid. Pure silica is colorless to white. in powder form. In this article we will refer to Advancure as "HMDA dispersion." It is a free-flowing, dust-free beaded beaded /bead·ed/ (bed´ed) having the appearance of beads or a string of beads. bead·ed adj. 1. Having numerous small rounded projections often in a row. 2. powder that can be used to cure the majority of Vamac products at a lower cost compared to traditional curing technologies. For the same activity level, replace 1 phr of hexmethylenediamine carbamate (HMDC) with 1.56 phr of HMDA dispersion. Procedure The HMDA dispersion is made by taking a 70/30 solution of hexamethylenediamine/water and making an absorbed liquid concentrate dispersion of it using a highly dispersible silica and a proprietary binder binder: see combine. An earlier Microsoft Office workbook file that let users combine related documents from different Office applications. The documents could be viewed, saved, opened, e-mailed and printed as a group. system as a carrier. The final active concentration of HMDA is 47%. The HMDA dispersion was tested against HMDC (hexamethylenediamine carbamate) in several different AEM compounds in Chem Technologies, DuPont and Gold Key Processing laboratories. Testing included rheology, initial cured physical properties and aged properties. This article includes data from three of these studies. Study #1--comparison of HMDA dispersion to HMDC from several sources This study was done in Gold Key's and Chem Technologies' laboratories. The mixing was done in a Moriyama 1.5 L lab 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. with a dump temperature of 93[degrees]C. Testing procedures used were: * MDR MDR, n See multidrug resistance. MDR, n the abbreviation for minimum daily requirement, specifically the Minimum Daily Requirements for Specific Nutrients compiled by the United States Food and Drug Administration. rheometer rhe·om·e·ter n. An instrument for measuring the flow of viscous liquids, such as blood. at 177[degrees]C (ASTM ASTM abbr. American Society for Testing and Materials D 5289-95); * 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 * Physical properties (tensile tensile, adj having a degree of elasticity; having the ability to be extended or stretched. , modulus See modulo. , elongation elongation, in astronomy, the angular distance between two points in the sky as measured from a third point. The elongation of a planet is usually measured as the angular distance from the sun to the planet as measured from the earth. and hardness) (ASTM D412-98a and ASTM D2240-05) using a press-cure of five minutes at 177[degrees]C and a post-cure of four hours at 177[degrees]C. The test formulations and cure properties are shown in table 1. Cure properties Compared to the HMDC compounds, the HMDA compound gave slightly higher maximum torque, a slightly longer cure time due to its higher maximum torque value, a slightly longer Mooney Ts5 scorch time and a slightly lower Mooney viscosity level. Physical properties (figures 2-5) * The HMDA compound had similar 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. values to the HMDC #1, 2 and 4 compounds. The HMDC #3 com pound had a lower durometer. * The HMDA compound had slightly higher tensile than the HMDC compounds. * The HMDA and the HMDC #2 compounds had slightly lower elongation at break values. * The HMDA compound had higher modulus than the HMDC control compounds. Study #2--Comparison of HMDA dispersion to HMDC in several AEM compounds This study was done in DuPont's laboratories. The mixing was done in a 00C internal mixer with a dump temperature of 100[degrees]C. Testing included the following: * MDR rheometer at 177[degrees]C (ASTM D 5289-95); * Mooney scorch at 121[degrees]C (ASTM D 1646-04); * Mooney viscosity 100 [degrees]C (ASTM D1646-04); * Unaged physical properties (tensile, modulus, elongation and hardness) (ASTM D412-98a and ASTM D2240-05) using a press-cure of five minutes at 175[degrees]C and a post-cure of four hours at 175[degrees]C; * Physical properties were also tested after one week aging in IRM (1) (Information Resource Management) See Information Systems and information management. (2) (Inherited Rights Mask) In NetWare 3.x and 4. 903 oil at 150[degrees]C (ASTM D471-98) and one week oven aging at 175[degrees](2 (ASTM D573-04); * Die C tear (ASTM D624-00); * Compression set (ASTM D395-02). This study evaluated HMDA dispersion versus HMDC in three different AEM compounds. * Formula #1: AEM compound with 10 phr 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 using a typical cure system of the diamine di·am·ine n. Any of various chemical compounds containing two amino groups, especially hydrazine. Noun 1. diamine - any organic compound containing two amino groups compound (HMDA or HMDC) with DOTG accelerator accelerator: see particle accelerator. (1) A key combination such as Alt-G or Ctrl-Shift H that is used to activate a task. (2) An incubator that expects to develop the company considerably faster than normal. See incubator. . * Formula #2: AEM compound with no plasticizer using the typical diamine/DOTG cure system. * Formula #3: AEM compound with no plasticizer and a "flex" cure system of the diamine with a DPG/DOTG accelerator blend. The formulations and properties are shown in table 2. Cure properties The HMDA compounds had similar maximum torque, Tc90 cure, TI0 scorch and viscosity values to the HMDC compounds. Physical properties--original unaged * The HMDA compounds hadslightly higher hardness than the HMDC compounds. * The HMDA compounds had slightly lower elongation and Die C tear values than the HMDC compounds. * The HMDA compounds had 50% modulus, tensile and compression set similar to the HMDC compounds. Physical properties--aged one week at 150[degrees]C in IRM903 oil * The HMDA compounds had similar change in durometer to the HMDC compounds. * The HMDA compounds had less change in 50% modulus than the HMDC compounds. * The HMDA compounds had similar change in tensile to the HMDC compounds. * The HMDA compounds had similar to less elongation change than the HMDC compounds. Physical properties--oven aged one week at 175[degrees]C in air * The HMDA compounds had similar retained durometer and 50% modulus to the HMDC compounds. * The HMDA compounds had similar to higher change in tensile compared to the HMDC compounds. * The HMDA compounds had less elongation change than the HMDC compounds. * The Formula #1 model compounds with 10 phr plasticizer had the most change in physical properties after heat aging. Study #3--comparison of HMDA dispersion to HMDC in a factory mix trial This study was done in Gold Key Processing's 45 L Krupp Krupp (kr  p), family of German armament manufacturers. The family settled in Essen in the 16th cent. pilot
intermesh mixer with a drop temperature of 93[degrees](2. Testing
included the following:
* MDR rheometer at 177[degrees](2 and 190[degrees]C, ASTM D 5289-95; * Mooney at 121[degrees](2, ASTM O 1646-04; and * physical properties (hardness, tensile, modulus, elongation), press-cured five minutes at 177[degrees]C, post-cured four hours at 177[degrees]C, ASTM D 412-98 and D 2240-05. The test formulations are shown in table 3. Cure properties (figures 6-11) [FIGURE 8 OMITTED] * The HMDA compound had slightly higher maximum torque values than the HMDC compound. * The HMDA compound had similar Tc90 cure times to the HMDC compound. * The HMDA compound gave a rheometer curve similar to the HMDC control, but with a higher state of cure at both 177[degrees] and 190[degrees]C. * The HMDA compound had a similar Mooney scorch time and viscosity to the HMDC compound. Physical properties (figures 12-15) * The HMDA compound had a similar hardness to the HMDC compound. * The HMDA compound had a slightly higher tensile and 100% modulus than the HMDC compound. * The HMDA compound had slightly lower elongation than the HMDC compound. Cost comparison The HMDA dispersion offers a significant cost savings versus the traditional HMDC curative, based on costing at the time this article was written (figure 16). Conclusions * The HMDA dispersion was tested in four different AEM compounds in two different laboratory studies, and also in factory trials, with similar cure and physical properties to HMDC. * The HMDA dispersion can offer significant cost savings compared to HMDC sources currently on the market. In a typical AEM formulation formulation /for·mu·la·tion/ (for?mu-la´shun) the act or product of formulating. American Law Institute Formulation this cost savings could result in a $0.15 to $0.20 per pound compound savings. This article is based on a paper presented at a meeting of the Rubber Division, ACS (Asynchronous Communications Server) See network access server. (www.rubber.org See .org. (networking) org - The top-level domain for organisations or individuals that don't fit any other top-level domain (national, com, edu, or gov). Though many have .org domains, it was never intended to be limited to non-profit organisations. RFC 1591. ). References (1.) "A Review of fast-cure systems for Vamac elastomers," Doc. Ref VAM VAM Vinyl Acetate Monomer VAM Vesicular-Arbuscular Mycorrhizae VAM Vitt Ariskt Motstånd (Swedish: White Aryan Resistance) VAM Vitt Ariskt Motstånd (Sweden) 020507_2, v.1, May 2002, E.I. DuPont de Nemours Nemours is a town and commune of the Seine-et-Marne département, in France. Geography Nemours is located on the Loing and its canal, 26 m. S. of Melun, on the Paris-Lyon railway. and Company, Inc. (2.) "Vamac polymer and performance review," DuPont Vamac web site, http://www2.dupont.com/Vamac/en_US/tech_info/vamac_indepth_polymers.html. (3.) "Vamac formulating and compounding overview," DuPont Vamac web site, http:// www2.dupont.com/Vamac/en_US/teeh_info/vamac_indepth_formulating.html. (4.) "Performance of AEM compounds in today's automotive service fluids," Doc. Ref VAM020507_3, v.1, May 2002, E.I. Du Pont de Nemours Du Pont de Ne·mours , Pierre Samuel 1739-1817. French-born economist and politician who took part in negotiations after the American Revolution (1783) and in the acquisition of the Louisiana Territory (1803). and Company, Inc. (5.) A.I. Moran Moran equitable councillor to King Feredach. [Irish Hist.: Brewer Dictionary, 728] See : Justice , R.P. Kane Kane can refer to: In sports:
(6.) U.S. Patent Application 20030204025, "Method of manufacturing cured ethylene acrylic and polyacrylate elastomers," Edward McBride, E.I. DuPont de Nemours and Company, Oct. 30, 2003.
Figure 2--durometer A hardness
HMDC #1 77.5
HMDC #2 78.2
HMDC #3 76.0
HMDC #4 78.0
HMDC 78.4
Note: Table made from bar graph.
Figure 3--tensile
HMDC #1 14.27
HMDC #2 13.85
HMDC #3 14.04
HMDC #4 14.59
HMDC 14.94
Note: Table made from bar graph.
Figure 4--elongation @ break
HMDC #1 215
HMDC #2 199
HMDC #3 215
HMDC #4 209
HMDC 198
Note: Table made from bar graph.
Figure 5--100 % modulus
HMDC #1 8.03
HMDC #2 7.76
HMDC #3 7.81
HMDC #4 8.41
HMDC 9.20
Note: Table made from bar graph.
Figure 6--MDR rheometer--maximum torque
HMDC HMDA
177[degrees]C 1.33 1.42
190[degrees]C 1.40 1.49
Note: Table made from bar graph.
Figure 7--MDR rheometer--[T[C.sub.90] cure
HMDC HMDA
177[degrees]C 3.83 4.10
190[degrees]C 2.61 2.65
Note: Table made from bar graph.
Figure 10--Mooney scorch at 121 [degrees]C
HMDC 5.96
HMDA 6.20
Note: Table made from bar graph.
Figure 11--Mooney viscosity at 121 [degrees]C
HMDC 29.58
HMDA 30.43
Note: Table made from bar graph.
Figure 12--hardness--durometer A
HMDC 77.2
HMDA 78.4
Note: Table made from bar graph.
Figure 13--tensile
HMDC 13.44
HMDA 14.28
Note: Table made from bar graph.
Figure 14--elongation
HMDC 220
HMDA 202
Note: Table made from bar graph.
Figure 15--100% moculus
HMDC 7.24
HMDA 8.13
Note: Table made from bar graph.
Figure 16--cost index
HMDC#1 100
HMDC#2 70
HMDC#3 80
HMDC#4 70
HMDA 45
Note: Table made from bar graph.
Table 1--study #1--formulations and cure properties
In phr (parts per HMDC # 1 HMDC #2 HMDC #3 HMDC #4 HMDA
hundred rubber)
AEM (Vamac G) 100.0 100.0 100.0 100.0 100.0
N-774 carbon 90.0 90.0 90.0 90.0 90.0
black
Stearic acid 2.0 2.0 2.0 2.0 2.0
Polyoxyethylene 1.5 1.5 1.5 1.5 1.5
octadecyl ether
phosphate
Octadecyl amine 0.5 0.5 0.5 0.5 0.5
Di (2-ethylhexyl) 10.0 10.0 10.0 10.0 10.0
sebacate
DOTG (di-o- 4.0 4.0 4.0 4.0 4.0
tolylguanidine)
HMDC #1 1.5
(hexamethylene-
diamine
carbamate) *
HMDC #2 * 1.50
HMDC #3 ** 2.00
HMDC #4 * 1.50
HMDA dispersion 2.34
(hexamethylene-
diamine) ***
* 100% active, ** 75% active on EP binder, *** 47% active on silica/
proprietary binder
Mixing details
Dump 93.3 93.3 93.3 93.3 93.3 93.3
temperature,
[degrees]C
Mix time 0.13 0.17 0.15 0.16 0.17
MDR rheometer at
177[degrees]C
Maximum torque 1.58 1.55 1.54 1.55 1.65
(N-m)
Ts2 scorch time 0.94 0.95 0.96 0.94 0.96
(minutes)
Tc90 (minutes) 6.00 6.12 6.27 6.06 6.86
Mooney scorch at
121[degrees]C
Ts5 scorch time 5.66 5.53 5.63 5.8 6.47
(minutes)
Viscosity ML 33.0 32.8 31.6 32.2 30.5
1+4
Table 2--study #2--formulations and properties
Model formula #1 Model formula #2
Standard Vamac Standard Vamac
compound with compound with
10 phr of no plasticizer
plasticizer
In phr (parts per HMDC HMDA HMDC HMDA
hundred rubber)
AEM (Vamac G) 100.0 100.0 100.0 100.0
Carbon black, N550 60.0 59.2 50.0 49.2
Ether/ester type 10.0 10.0 0.0 0.0
plasticizer
Stearic acid 1.5 1.5 1.5 1.5
Polyoxyethylene 1.0 1.0 1.0 1.0
octadecyl ether
phosphate
Octadecyl amine 0.5 0.5 0.5 0.5
4, 4' Di(a,a- 2.0 2.0 2.0 2.0 2.0
dimethylbenzyl)
diphenylamine
HMDC (100% 1.50 1.50
active)
HMDA dispersion 2.34 2.34
(47% active)
DPG
DOTG 4.00 4.00 4.00 4.00
MDR rheometer at
177[degrees]C
Maximum torque 1.29 1.30 1.48 1.44
(N-m)
Tc90 (minutes) 8.60 8.96 8.80 9.58
Mooney scorch at 14.1 14.7 13.4 13.8
121[degrees]C,
t10 (minutes)
Mooney viscosity at 33.0 32.7 43.8 42.8
100[degrees]C,
ML 1+4
Original unaged
properties
Hardness, 71.7 72.8 70.5 72.4
durometer A
(points)
50% modulus (MPa) 2.20 2.30 2.34 2.37
100% modulus 4.92 5.30 5.52 5.58
(MPa)
Tensile strength 16.18 16.49 18.78 17.13
(MPa)
Elongation at 309 290 330 257
break (%)
Die C tear (MPa) 1.36 1.30 1.39 1.31
Compression set, 23.5 22.6 17.6 18.4
7 days at
150[degrees]C (%)
Aged 1 week at
150[degrees]C in
IRM903 Oil
Durometer -21.4 -21.6 -19.3 -20.4
hardness change
(points)
% change in 50% -24% -17% -30% -18%
modulus
% change in -28% -27% -39% -35%
tensile strength
% change in -35% -36% -40% -36%
elongation
Oven aged 1 week at
175[degrees]C in
air
Durometer 9.5 10.1 3.9 4.1
hardness change
(points)
% change in 50% 81% 83% 19% 22%
modulus
% change in +6% +6% +1% +12%
tensile strength
% change in -19% -16% -8% +7%
elongation
Model formula #3
Vamac compound
with no plasticizer
and with "flex" cure
In phr (parts per HMDC HMDA
hundred rubber)
AEM (Vamac G) 100.0 100.0
Carbon black, N550 50.0 49.36
Ether/ester type 0.0 0.0
plasticizer
Stearic acid 1.5 1.5
Polyoxyethylene 1.0 1.0
octadecyl ether
phosphate
Octadecyl amine 0.5 0.5
4, 4' Di(a,a- 2.0 2.0 2.0
dimethylbenzyl)
diphenylamine
HMDC (100% 1.20
active)
HMDA dispersion 1.87
(47% active)
DPG 2.00 2.00
DOTG 2.00 2.00
MDR rheometer at
177[degrees]C
Maximum torque 0.91 0.95
(N-m)
Tc90 (minutes) 9.66 9.79
Mooney scorch at 12.8 12.9
121[degrees]C,
t10 (minutes)
Mooney viscosity at 42.4 42.2
100[degrees]C,
ML 1+4
Original unaged
properties
Hardness, 67.9 68.6
durometer A
(points)
50% modulus (MPa) 1.88 1.89
100% modulus 3.95 4.00
(MPa)
Tensile strength 17.88 18.52
(MPa)
Elongation at 431 406
break (%)
Die C tear (MPa) 1.53 1.37
Compression set, 21.9 23.9
7 days at
150[degrees]C (%)
Aged 1 week at
150[degrees]C in
IRM903 Oil
Durometer -23.7 -23.6
hardness change
(points)
% change in 50% -32% -23%
modulus
% change in -32% -29%
tensile strength
% change in -40% -36%
elongation
Oven aged 1 week at
175[degrees]C in
air
Durometer 3.9 5.0
hardness change
(points)
% change in 50% 25% 25%
modulus
% change in -8% -10%
tensile strength
% change in -19% -13%
elongation
Table 3--study #3 formulations
In phr (parts per hundred rubber) HMDC HMDA
AEM (Vamac G) 100.0 100.0
N-774 carbon black 90.0 90.0
Stearic acid 2.0 2.0
Polyoxyethylene octadecyl 1.5 1.5
ether phosphate
Octadecyl amine 0.5 0.5
Di (2-ethylhexyl) sebacate 10.0 10.0
DOTG 4.0 4.0
HMDC #1 (100% active) 1.50
HMDA dispersion (47% active) 2.30
|
|
||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion