Printer Friendly

Structure and properties of nylon 1010/ethylene-vinyl acetate rubber-based dynamically vulcanized thermoplastic elastomers filled with Si[O.sub.2].

INTRODUCTION

Thermoplastic elastomers (TPEs) have drawn considerable attention owing to many valuable properties. TPEs combine some advantages of both plastics and rubbers. TPEs can be derived from either block copolymers or rubber/plastic blends. TPE usually consists of a thermoplastic matrix and a dispersed crosslinked rubber phase. Under the shear forces, the crosslinked rubber is unable to coalesce and to be dispersed in the thermoplastic matrix even at high rubber content [1, 2]. The composition and the processing conditions always affect the size of rubber particles. TPEs show fairly good elastic behavior because both the rubber particles and the thin plastic layers surrounding the particles behave elastically on deformation [3-5].

Nylon is a kind of engineering plastics and has high stiffness and good resistance to hydrocarbon solvents. TPEs based on nylon with various rubbers have been studied extensively for many years [5, 6]. Crisenza et al. [7] reported phase-separated morphology in chlorinated polyethylene (CPE) and nylon-6/6,6/-12 terpolyamide (PA) TPEs. They used three-dimensional laser scanning confocal fluorescent microscopy to study the morphology of the elastomers and revealed that the co-continuous structures responsible for the improved mechanical properties of the CPE/PA (60:40) blend. Naderi et al. [8] prepared the nanoclay-filled polyepichlorohydrin-co-ethylene oxide (ECO)/PA6 TPEs and found that the organoclay increased the size of dispersed rubber particles and affected the tensile modulus. Liu et al. [9] studied a thermoplastic vulcanizate (TPV) of ethylene-propylene-diene and PA with excellent mechanical properties through a dynamic vulcanization and found that CPE could improve the compatibility of the blends.

Nylon 1010 is an important polyamide, and its toughening with elastomers has drawn great attention [10-16]. Yu et al. [14] studied the toughening effect of ethylene-vinyl acetate rubber (EVM) on Nylon 1010. They found that the notched Izod impact strength of Nylon/EVM blends increased with increasing EVM content, and the compatibility of Nylon/EVM blend was improved after adding maleated ethylene-vinyl acetate copolymers (EVA-g-MA). Furthermore, they compared the toughening effects of three different elastomers on Nylon 1010 [13], They revealed that EVM had the best toughening effect on Nylon 1010 in the absence of compatibilizer were added. Fang et al. [17] studied the thermal and mechanical properties of Nylon 1010 filled with two kinds of Si[O.sub.2] particles surface-modified by saturated organic carbon chains (DNS) and reactive functional amide group (RNS), respectively. They found that the Nylon 1010 nanocomposites had better thermal stability than Nylon 1010, and the composites filled with RNS were more thermally stable than those filled with DNS.

EVM is a kind of special rubber and can be used as halogen-free flame-retardant and oil-resistant electrical wires and cables. Nylon 1010 is a plastic with good mechanical properties. Nylon 1010/EVM blend would be expected to combine the advantages of Nylon 1010 and EVM and used in the electrical wires and cables, construction, and automotive fields. However, Nylon and EVM are thermodynamically immiscible. In our study, maleic anhydride grafted ethylene-vinyl acetate copolymer (EVA-g-MA) was used as a compatibilizer to improve the compatibility of the Nylon/EVM blends, Si[O.sub.2] was used as reinforcing filler to improve the tensile properties of the blends. Therefore, this research might provide a method to get high tensile strength TPE nanocomposites.

In this study, the structure and properties of Si[O.sub.2] filled Nylon 1010/EVM TPE nanocomposites were studied. The dynamically vulcanized Nylon 1010/EVM TPEs were prepared via master batch method, and EVA-g-MA was used as a compatibilizer for improving interfacial adhesion of the two phases. Nanofillers are usually used to enhance the blends, but they are difficult to be dispersed uniformly owing to their high polarity and large surface area. Herein, Si[O.sub.2] was added into the blends and a silane coupling agent (KH550) was used to improve the dispersion of Si[O.sub.2] in the polymer matrix. Different factors such as the amounts of EVA-g-MA and Si[O.sub.2] were studied to reveal their effects on the properties of the TPEs. The rheological behavior, morphology, non-isothermal crystallization behavior, and mechanical properties of the resulting nanocomposites were studied.

EXPERIMENTAL SECTIONS

Materials

Nylon 1010 was produced by Shanghai Salient Chemical Co., with an intrinsic viscosity of 83.4 mL [g.sup.-1] (25[degrees]C, 96% [H.sub.2]S[O.sub.4]). EVM was kindly supplied by Lanxess Company (Germany) with a 40 wt% VA content and a Moony viscosity (M [L.sup.100[degrees]C.sub.1+4]) of 20. Ethylene-vinyl acetate (EVA 14) was produced by Beijing Organic Chemical Company (China) with a 14 wt% VA content. Aerosil-200 fumed silica (a kind of hydrophilic silica, surface area 200 [+ or -] 25 [m.sup.2] [g.sup.-1], primary particle size 12 nm, purity 98%) was produced by Evonik Degussa (Germany), and dried in a vacuum oven overnight at 100[degrees]C before use. Dicumyl peroxide (DCP), silane coupling agent (KH550, 3-triethoxysilylpropylamine), and maleic anhydride (MA) were used as received.

Blends Preparation

Preparation of EVA-g-MA. EVA was dried at 80[degrees]C under vacuum for at least 10 h before use. MA was grafted onto the EVA in a co-rotating twin-screw extruder (Berstorff GmbH, Germany) with a diameter of 25 mm and a length/diameter ratio of 41. The MA grafting degree was 0.72% as measured by titration method.

Preparation of the TPEs via Dynamic Vulcanization Process. Nylon 1010 was dried at 80[degrees]C for more than 12 h and EVM was dried at 60[degrees]C for 4 h. A sample was prepared in the mixing chamber of a Haake rheometer RC 90 (Germany) at a rotor speed of 50 rpm and a set temperature of 210[degrees]C via a master-batch method. First, EVM and DCP were mixed on a two-roll mill. Then, Nylon 1010 and EVA-g-MA were added into the chamber and mixed for 2 min followed by adding the EVM compound. Sequently, mixing lasted for 8 min. The compounds were compression-molded at 220[degrees]C under a pressure about 10 MPa. The TPEs filled with Si[O.sub.2] were prepared following a similar procedure. EVM/Si[O.sub.2]/KH550/DCP compounds were first prepared on two-roll mill, and then added into the mix chamber containing Nylon/EVA-g-MA blends.

Characterization

Tensile properties were measured using an Instron 4465 test machine at a crosshead speed of 200 mm [min.sup.-1] according to GB/T 528-2009.

The dynamic mechanical behavior of TPE was determined using a dynamic mechanical analyzer (DMA, TA-Q800) in tensile mode at 10 Hz and a heating rate of 3[degrees]C [min.sup.-1] in the temperature range of -60 to 100[degrees]C.

Phase morphology of the cryofractured blend sample was investigated by a scanning electron microscope (SEM, Hitachi-S-2150, Japan) with an accelerating voltage of 15 kV. Nylon 1010 phase was etched out by hot formic acid for 60 min [18] and dried under vacuum oven at 60[degrees]C for 30 min to remove the traces of solvents, and gold sputtered for SEM observation.

The filler dispersion in nanocomposite was examined using a JEM-2010HT transmission electron microscope operating at 120 kV. The sample was ultramicrotomed with a diamond knife on a Leica Ultracut UCT UC6 in liquid nitrogen to give 70 nm-thick sections.

Atomic force microscopy (AFM) images were obtained in a tapping mode on a BioScope (Digital Instrument). The cantilevers had a spring constant of 40 [Nm.sup.-1] and a resonance frequency of 300 kHz. Samples with ultrasmooth surface were prepared with a microtome in liquid nitrogen.

Oscillatory rheological measurement of TPE was performed in an AR-G2 rotational rheometer at 230[degrees]C using a parallel plate geometry. The gap and diameter of the plates were 1 mm and 25 mm, respectively. A frequency sweep from 0.1 to 100 rad [s.sup.-1] under constant strain was applied for each sample.

The non-isothermal crystallization kinetics was investigated under a [N.sub.2] atmosphere using a PE differential scanning calorimeter (DSC-2). For non-isothermal crystallization, a sample was first heated from room temperature to 240[degrees]C at 30[degrees]C [min.sup.-1], and held there for 5 min to eliminate its thermal history. Subsequently, the sample was cooled to room temperature at 5, 10, 20, and 40[degrees]C [min.sup.-1], respectively.

RESULTS AND DISCUSSION

EVA-g-MA was added into Nylon/EVM blends to improve compatibility, the effect of its content on the mechanical properties of the blends is shown in Fig. 1, and the data are summarized in Table 1.

With increasing EVA-g-MA content, the tensile strength and elongation at break of Nylon 1010/EVM vulcanizates increased rapidly and reached the maximum values of 11.0 MPa and 223%, respectively, when the compatibilizer content was 15 wt%. When further increasing EVA-g-MA content to 20 wt%, the mechanical properties became poor. Hence, the optimum EVA-g-MA content was 15 wt%. Compatibilizers can enhance the interaction between two components of the blends. The addition of the suitable amount of the compatibilizer improves the mechanical properties of the blends. But, over loading of the compatibilizer did not favor to the improvement of the mechanical properties anymore because the compatibilizer surrounded the rubber phase was saturated. In Nylon/EVM blends, chemical reactions would take place between EVA-g-MA and Nylon 1010 macromolecules, which improved the interfacial interaction. A small amount of chemical bonds existed between Nylon 1010 and rubber macromolecules, the mechanical properties of the blends should be improved. A similar result was reported by Liu et al. [9, 19].

To study the enforcement of Si[O.sub.2] for the blends, 20 and 40 phr Si[O.sub.2] were added into the blends. The mechanical properties of the resultant Nylon 1010/EVMs are shown in Table 2. Compared with the blend without Si[O.sub.2] (Nylon/EVM/DCP = 30/70/ 0.8), the tensile strength of the blends was increased from 4.7 MPa to 7.1 MPa (TPE with 20 phr Si[O.sub.2]) and 8.8 MPa (TPE with 40 phr Si[O.sub.2]), respectively.

Different amounts of Si[O.sub.2] were introduced into Nylon/EVM/ DCP/EVA-g-MA (30/70/0.8/15) blend. The tensile strength of the blend increased after adding Si[O.sub.2]. When the Si[O.sub.2] loading increased to 40 phr, the tensile strength of the blend reached 16.3 MPa. This value was much higher than that of the blend without Si[O.sub.2], indicating Si[O.sub.2] is a good reinforcing filler for the blend. The elongation at break of the blend decreased after adding Si[O.sub.2], which might be resulted from the stress concentration of Si[O.sub.2].

Because of its high polarity and large surface area, Si[O.sub.2] is difficult to be homogeneously dispersed in polymers. Silane coupling agents are often used to decrease the strong filler-filler interactions and increase the filler-rubber interactions. Herein, KH550 was used as a coupling agent with a loading about 10 wt% of Si[O.sub.2] content correspondingly. A blend without coupling agent (Nylon/EVM/EVA-g-MA/DCP = 30/70/15/0.8) was prepared, and the mechanical properties were given in Table 2. This blend showed a tensile strength of 5.8 MPa and elongation at break of 30%. However, after adding the coupling agent (KH550), the tensile strength and elongation at break increased to 16.3 MPa and 180%, respectively, which could be resulted from better dispersion of Si[O.sub.2] and stronger filler-rubber interaction in the presence of KH550.

Tan [delta] curves of Nylon 1010/EVM TPVs are shown in Fig. 2 and the data of [T.sub.g] (glass transition temperature) are summarized in Table 3. The Nylon/EVM blends showed two tan [delta] peaks corresponding to [T.sub.g] of Nylon and EVM. As the loading of compatibilizer increased, [T.sub.g] peaks of EVM and Nylon moved closer each other, indicating better compatibility. It indicates that EVA-g-MA could improve the compatibility of the Nylon/EVM blends significantly. The two separated tan [delta] peaks imply that the blends are still phase separated and the addition of compatibilizer could not make the blends completely miscible.

SEM morphology of the Nylon/EVM TPEs are shown in Fig. 3. In Fig. 3a, for the blend without any compatibilizer, clear contour of EVM phase can be distinguished. However, in Fig. 3b, larger size rubber phase with rough surface appeared and the phase boundary between the rubber phase and the Nylon matrix is blurry, indicating that the interfacial adhesion between the Nylon 1010 matrix and EVM phase is enhanced. The larger size rubber phase in Fig. 3b should be the aggregate of some smaller rubber particles. The agglomerate surface indicates that the incorporation of compatibilizer can lead to size reduction of rubber phase [20],

SEM observations were also performed to investigate the effect of the coupling agent (KH550) on the dispersion of Si[O.sub.2] in the blends. As shown in Fig. 4a, in the blend without KH550, the agglomeration of Si[O.sub.2] particles can be observed clearly. This implies an uneven dispersion of Si[O.sub.2] in the absence of KFI550 and poor interaction between polymer matrix and Si[O.sub.2]. After adding the coupling agent KH550, as shown in Fig. 4b, the Si[O.sub.2] was dispersed uniformly in the blends. The white Si[O.sub.2] particles became blurred, which might be because some polymer chains wrapped on the particles and led to a better interaction between polymer matrix and Si[O.sub.2] particles. It proved that the coupling agent KH550 was necessary for dispersion Si[O.sub.2] for the Nylon/EVM TPVs [21].

The localization of Si[O.sub.2] in the polymer blend could be clearly seen from TEM image as shown in Fig. 5, in which the light and gray parts correspond to discrete EVM and matrix Nylon phases, respectively. It can be seen that most Si[O.sub.2] particles were dispersed in EVM phase and some Si[O.sub.2] particles were located at the interface of the two phases. There were few Si[O.sub.2] particles dispersed in Nylon phase, indicating Si[O.sub.2] particles present a greater affinity for EVM than for Nylon.

The morphology was investigated by AFM as well. As shown in Fig. 6, the crosslinked rubber phase (white) was dispersed in the Nylon matrix (dark). The size of dispersed phase (EVM) was larger than 5 [micro]m in Fig. 6a and less than 1 [micro]m in diameter in Fig. 6b, respectively. This indicates that the addition of EVA-g-MAH could improve the distribution homogeneity of the rubber particles as well as decreased the rubber particle size.

As shown in Fig. 7, the complex viscosity of all the blends decreased significantly with increasing shear frequency, indicating all the blends showed a non-Newtonian behavior. The complex viscosity of Nylon 1010/EVM/DCP (30/70/0.8) was higher than that of Nylon/EVM (30/70), which was resulted from the crosslinking of EVM phase. The viscosity values of the blends with EVA-g-MA as a compatibilizer were between that of Nylon 1010/EVM (30/70) and Nylon 1010/EVM/DCP (30/70/0.8). The viscosity values of the blends increased with increasing the compatibilizer content. This could be interpreted by that the graft reactions between compatibilizer and Nylon leading to a higher viscosity as increasing the compatibilizer loading. However, the complex viscosities of three compatibilized samples were lower than that of Nylon 1010/EVM/DCP (30/70/0.8). The possible reason is that EVA-g-MA might introduce a plasticization effect accompanying the compatibilization effect.

The effect of DCP content on the non-isothermal crystallization behavior of Nylon/EVM blend was studied. Figure 8 shows the non-isothermal crystallization exotherms of Nylon/EVM (30/ 70) and Nylon/EVM/DCP (30/70/0.8) blends at different cooling rates. It can be seen that all the Nylon/EVM and Nylon/EVM/ DCP blends show a single crystallization peak around 180[degrees]C. The peak temperature ([T.sub.p]) of Nylon/EVM/DCP was higher than that of Nylon/EVM with the same cooling rate, indicating that the heterogeneous nucleation effect of crosslinked rubber particles was more notable that the uncrosslinked rubber phase for Nylon. Comparing different cooling rates, [T.sub.p] of each blend shifted to low temperature as increasing the cooling rate, which implied that there was no enough time to activate the nuclei at high temperature when crystallized at high cooling rate.

It is well known that isothermal crystallization kinetics of polymers is commonly studied by the Avrami method [22].

1 - [X.sub.t] = exp(-[Z.sub.t][t.sup.n]) (1)

where the Avrami exponent n contains information on nucleation and crystal growth, [Z.sub.t] is crystallization rate constant, [X.sub.t] is the relative degree of crystallinity at different temperatures.

Several methods based on the Avrami equation have been developed successively. For example, Ozawa [23] assumed that the non-isothermal crystallization process was composed of infinite small isothermal crystallization steps and extended the Avrami equation to the non-isothermal process. Ozawa's theory can be expressed as:

1 - C(T) = exp [-K(T)/[R.sup.m]] (2)

where C(T) is the relative degree of crystallinity at temperature T, K(T) is the cooling crystallization function, R is the cooling rate, and m is the Ozawa exponent which is related to the mechanism of nucleation and dimension of crystal growth. Equation 2 can be rewritten as

log[-ln(1 - C(T))] = log K(T) - m log R (3)

By plotting log[-ln(1 - C(T))] against log R, a straight line should be obtained if the Ozawa method is valid and kinetics parameter (m and K(T)) can be derived from the slope and the intercept, respectively. Later on, Jeziomy [24] directly adopted the Avrami equation (Eq. 1)

log[-ln (1 - [X.sub.t])] = log [Z.sub.t] + n log t (4)

to the non-isothermal crystallization kinetics of polymers.

Mo and coworkers [25] developed a new model for non-isothermal crystallization kinetics by combining the Avrami equation with the Ozawa equation. In this case, the relationship of t, T, and R can be expressed as:

t = ([T.sub.0] - T)/R (5)

where [T.sub.0]) is the initial crystallization temperature, T is the crystallization temperature at time t, and R is the cooling rate. Therefore, curves of [X.sub.t] versus T (Fig. 9) can be converted into curves of [X.sub.t] versus t, which are shown in Fig. 10.

Combining Eqs. 3-5, the following equation can be obtained at a given crystallinity degree:

log X = log F(T) - [alpha] log t (6)

where F(T) = [[K(T)/[Z.sub.t]]/sup.1/m] is defined as the cooling rate to obtain a certain relative crystallinity in one unit of time, representing the crystallization rate of polymers, [alpha] = n/m, in which n and m are the Avrami exponent and the Ozawa exponent, respectively.

According to Eq. 6, a good linear relationship between log R and log t for the two blends at a given crystallinity degree appeared as shown in Fig. 11. The intercept and the slope obtained from the line represent F(T) and [alpha], respectively, and are listed in Table 4. From Table 4, the cooling rate needed for Nylon/EVM/DCP to obtain a certain relative crystallinity in one unit of time was lower than that for Nylon/EVM. To obtain the same crystallinity in one unit of time, the cooling rates for the Nylon/EVM blend need to be higher than that of Nylon/EVM/ DCP. This indicated that the crosslinked rubber particles in the blends promoted the crystallization of Nylon, leading to higher crystal growth rate compared to that of Nylon/EVM blend, [alpha] value slightly changed from 1.00 to 1.03 and from 0.96 to 0.99 for Nylon/EVM and Nylon/EVM/DCP, respectively. Therefore, Eq. 6 successfully described the non-isothermal crystallization of Nylon/EVM blends.

CONCLUSIONS

TPEs based on Nylon 1010/EVM have been successfully prepared through dynamic vulcanization using DCP as curing agent. The addition of compatibilizer EVA-g-MA and Si[O.sub.2] could effectively improve the compatibility and the mechanical properties of the blends. DMA analysis revealed the EVA-g-MA could improve the compatibility of the blends. SEM and AFM analysis indicated that EVA-g-MA could decrease the size of the crosslinked rubber particles. KH550 could promote the dispersion of Si[O.sub.2] and enhance the interaction between Si[O.sub.2] and polymer matrix. The Nylon/EVM/DCP (30/70/0.8) TPE with 15 phr EVA-g-MA, 40 phr Si[O.sub.2], and 4 phr KH550 had the highest tensile strength of 16.3 MPa and elongation at break of 180%. The addition of DCP promoted the crystallization of Nylon in the non-isothermal crystallization process of Nylon/EVM blend.

REFERENCES

[1.] P. Sengupta and J.W.M. Noordermeer, Macromol. Rapid Coalman., 26, 542 (2005).

[2.] R.R. Babu and K. Naskar. Adv. Rubber Compos., 239, 219 (2011).

[3.] Y. Kikuchi, T. Fukui, T. Okada, and T. Inoue, J. Appl. Polym. Sci.: Appl. Polym. Sympos., 50, 261 (1992).

[4.] S. Kawabata, S. Kitawaki, H. Arisawa, Y. Yamashita, and X. Guo, J. Appl. Polym. Sci.: Appl. Polym. Sympos., 50, 245 (1992).

[5.] J. Oderkerk, G. De Schaetzen, B. Goderis, L. Hellemans, and G. Groeninckx, Macromolecules, 35, 6623 (2002).

[6.] J. Oderkerk, G. Groeninckx, and M. Soliman, Macromolecules, 35, 3946 (2002).

[7.] T. Crisenza, H.J. Butt, K. Koynov, and R. Simonutti, Macromol. Rapid Commun., 33, 114 (2012).

[8.] G. Naderi, M. Razavi-Nouri, E. Taghizadeh, P.G. Lafleur, and C. Dubois, Polym. Eng. Sci., 51, 278 (2011).

[9.] X. Liu, H. Huang, Z. Xie, Y. Zhang, Y. Zhang, K. Sun, and L. Min. Polym. Test., 22, 9 (2003).

[10.] S.L. Zhang, G.B. Wang, Z.H. Jiang, D. Wang, R.T. Ma, and Z.W. Wu, J. Polym. Sci. Part B: Polym. Phys., 43, 1177 (2005).

[11.] H. Chen, B. Yang, and H. Zhang, J. Appl. Polym. Sci., 77, 928 (2000).

[12.] H. Yu, Y. Zhang, and W. Ren, Polym. Eng. Sci., 49, 2393 (2009).

[13.] H. Yu, Y. Zhang, W. Ren, M. Hoch, and S. Guo, J. Appl. Polym. Sci., 121, 3340 (2011).

[14.] H. Yu, Y. Zhang, and W. Ren, J. Polym. Sci. Part B: Polym. Phys., 47, 434 (2009).

[15.] H. Yu, W. Ren, and Y. Zhang, J. Appl. Polym. Sci., 113, 17 (2009).

[16.] H. Yu, Y. Zhang, and W. Ren, J. Appl. Polym. Sci., 113, 181 (2009).

[17.] X.W. Fang, X.H. Li, L.G. Yu, and Z.J. Zhang, J. Appl. Polym. Sci., 115, 3339 (2010).

[18.] R. Rajesh Babu, N.K. Singha, and K. Naskar, Polym. Eng. Sci., 50, 455 (2010).

[19.] L. Cui, S. Wang, and Y. Zhang, J. Appl. Polym. Sci., 104, 3337 (2007).

[20.] Y. Chen, C. Xu, L. Cao, Y. Wang, and X. Cao, Polym. Test., 31, 728 (2012).

[21.] W. Wu, C. Wan, and Y. Zhang, J. Appl. Polym. Sci., 130, 338 (2013).

[22.] M. Avrami, J. Client. Phys., 8, 212 (1940).

[23.] T. Ozawa, Polymer, 12, 150 (1971).

[24.] A. Jeziorny, Polymer, 19, 1142 (1978).

[25.] T. Liu, Z. Mo, S. Wang, and H. Zhang, Polym. Eng. Sci., 37, 568 (1997).

Xianbo Lu, Hongmei Zhang, Yong Zhang

State Key Laboratory of Metal Matrix Composites, 129 Chemistry Building, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan RD, Minhang District, Shanghai 200240, China

Correspondence to: Yong Zhang; e-mail: yong_zhang@sjtu.edu.cn

Contract grant sponsor: National Natural Science Foundation of China; contract grant number: 51073092.

DOI 10.1002/pen.23920

Published online in Wiley Online Library (wileyonlinelibrary.com).

TABLE 1. Effect of EVA-g-MA content on the mechanical properties of
Nylon 1010/EVM vulcanizates.

EVA-g-MA   Tensile
content    strength    Elongation    Stress at 100%     Set at
(phr)       (MPa)     at break (%)   extension (MPa)   break (%)

0            4.7           27              --             5.0
5            7.3           96              --             18
10           9.5          179              8.1            50
15           11.0         223              8.2            89
20           9.4          158              8.0            60

Basic formulation: Nylon 30; EVM 70; DCP 0.8; EVA-g-MA variable.

TABLE 2. Mechanical properties of Nylon 1010/EVM thermoplastic
elastomers with different amount of Si[O.sub.2].

                                                            Stress
EVA-g-MA   Si[O.sub.2]    KH550    Tensile    Elongation    at 100%
content      content     content   strength    at break    extension
(phr)         (phr)       (phr)     (MPa)        (%)         (MPa)

0              20           2         7.1         68           --
0              40           4         8.8         89
15              0           0        11.0        223          8.2
15             10           1        11.6        137          8.7
15             20           2        12.8        154          9.3
15             30           3        13.6        168          9.8
15             40           4        16.3        180         11.0
15             40           0         5.8         30           --

TABLE 3. [T.sub.g] of Nylon 1010/EVM TPV
with different compatibilizer content.

                 [T.sub.g]    [T.sub.g] (Nylon
EVA-g-MA           (EVM,         1010,
content (phr)   [degrees]C)   [degrees]C)

0                  -20.5         72.4
5                  -20.5         68.7
10                 -19.1         66.3
15                 -18.2         65.8

Basic formulation: Nylon 30; EVM 70;
DCP 0.8; EVA-g-MA variable.

TABLE 4. Values of F(T) and [alpha] for Nylon/EVM and Nylon/EVM/DCP
blend.

Sample          [X.sub.t] (%)   log F(T)   F(T)   [alpha]

Nylon/EVM            10           1.58     38.2    1.00
                     30           1.59     39.3    1.00
                     50           1.61     40.9    1.01
                     70           1.62     42.2    1.02
                     90           1.65     44.9    1.03

Nylon/EVM/DCP        10           1.47     29.6    0.96
                     30           1.49     31.1    0.97
                     50           1.50     32.0    0.97
                     70           1.52     33.5    0.98
                     90           1.55     35.8    0.99
COPYRIGHT 2015 Society of Plastics Engineers, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2015 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Lu, Xianbo; Zhang, Hongmei; Zhang, Yong
Publication:Polymer Engineering and Science
Article Type:Report
Date:Mar 1, 2015
Words:4312
Previous Article:Melt-blended halloysite nanotubes/wheat starch nanocomposites as drug delivery system.
Next Article:Preparation and properties of monomer casting nylon-6/PEO blend prepared via in situ polymerization.
Topics:

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters