动态硫化制备PA/SAN/NBR合金冲击性能的研究

采用酚醛树脂（PF）、DCP和硫磺等硫化体系对PA／SAN／NBR共混体系进行动态硫化,研究了该共混体系的缺口冲击强度、冲击行为和分散相形态。结果发现,PF比其它硫化体系更有效,可制得超韧的PA／SAN／NBR（50／25／25）合金;SEM照片表明,随着PF用量增加,共混体系中分散相粒子变小,形态变规则,动态硫化体系的相容性变好。     

Properties and morphologies of PVC/nylon terpolymer blends

A new kind of blends of polyvinyl chloride (PVC)/nylon terpolymer was reported in this article. Two compatibilizers were used in this study: one is a terpolymer of ethylene–n‐butyl acrylate–monoxide (EnBACO); the other is terpolymer of EnBACO grafted with maleic anhydride (EnBACO‐g‐MAH). The observation of scanning electron microscope (SEM) reveals that the PVC/nylon terpolymer blends have a two‐phase structure; and the nylon terpolymer phase is the continuous phase, and PVC domains in the PVC/nylon terpolymer/EnBACO‐g‐MAH blends have fine dispersion over a broad range of the PVC/nylon terpolymer ratio. EnBACO‐g‐MAH is more compatible with the nylon terpolymer than EnBACO. EnBACO and EnBACO‐g‐MAH have different effects on the glass transition temperatures of the PVC phase and nylon terpolymer phase in the blends. The notched Izod impact strength, tensile strength, elongation at break, Vicat softening temperature (VST), and melt flow index (MFI) critically depend on PVC/nylon terpolymer ratio, the kinds and concentration of the compatibilizers. The PVC/nylon terpolymer/EnBACO‐g‐MAH blends display a good combination of high toughness, high flowability, and high VST under low load. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2823–2832, 2001     

共混比对丁腈橡胶/氯醚橡胶性能的影响

研究了共混比时常规共混及动态硫化共混丁腈橡胶(NBR)／氯醚橡胶(ECO)的力学性能及加工流变性能的影响。结果表明,共混比对NBR／ECO胶料的力学性能及加工流变性能影响显著。NBR经动态硫化后,压缩永久变形及挤出胀大明显减小,拉伸强度提高,表现黏度随ECO用量的增大而减小。共混比对常规共混胶的表观黏度影响不大。动态硫化有利于改善NBR／ECO胶料的加工性能。     

Morphology and physical properties of SAN/NBR blends: The effect of AN content in NBR

Poly(styrene‐co‐acrylonitrile) (SAN), of which the content of acrylonitrile (AN) repeating unit is 32 wt % (SAN32), was blended with poly(butadiene‐co‐acrylonitrile) (NBR). The effects of AN repeating unit content in NBR on the miscibility, morphology, and physical properties of SAN32/NBR (70/30 by weight) blends were studied. Differential scanning calorimetry and the morphology observed by transmission electron microscopy showed that the miscibility between SAN32 and NBR was increased as the AN content in NBR was increased up to 50 wt %. The impact strength and some other mechanical properties of the blends had the maximum value when the AN content in NBR was 34 wt %. In the measurement of viscoelasticity at melt state, SAN32/NBR blends showed yield behavior at low shear rate, and this behavior was most evident when the AN content in NBR was 34 wt %. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1861–1868, 2000     

三元尼龙对丁腈橡胶力学性能及耐介质性的影响

采用三元尼龙改性丁腈橡胶（NBR）,研究尼龙用量对NBR混炼胶加工工艺性能和硫化胶力学性能、耐老化性能、耐介质性能的影响。结果表明：尼龙的添加有效地提高了NBR硫化胶的强度以及耐磨性能,老化性能也得到改善,拉伸强度基本上是随着尼龙用量的增加而增大,其中尼龙用量为5phr时,硫化胶的综合物理机械性能较好;耐油系数亦随阻尼用量的增加而逐渐增大,尼龙的加入提高了硫化胶的耐热油性;耐混合溶剂后的体积变化率随着尼龙用量的增加而逐渐降低。     

氯化聚乙烯对三元乙丙橡胶与丁腈橡胶并用胶物理机械性能的影响

研究了氯化聚乙烯对EPDM／NBR并用胶物理机械性能的影响。结果发现，加入氯化聚乙烯后，并用胶的混合平衡扭矩降低，达到平衡扭矩所需的时间缩短，且无论用硫黄硫化还是用过氧化物硫化，硫化胶的物理机械性能都提高，表明氯化聚乙烯对EPDM／NBR并用胶有一定的增容作用。同时也发现用过氧化物硫化的EPDM／NBR并用胶物理机械性能优于硫黄硫化的并用胶物理机械性能。     

官能化高乙烯基聚丁二烯橡胶与丁腈橡胶共混胶的性能

以氢化钠为活性剂、马来酸酐为改性剂,通过负离子反应对高乙烯基聚丁二烯橡胶(HVBR)进行官能化改性制备了官能化HVBR(FHVBR)。考察了FHVBR与丁腈橡胶(NBR)共混的质量比对FHVBR/NBR共混胶硫化特性、力学性能、耐热氧老化性能和电性能的影响,并通过差示扫描量热仪和扫描电子显微镜探讨了共混胶的两相相容性。结果表明,随着NBR用量的增加,FHVBR/NBR共混胶的硫化时间缩短、硫化效率提高,定伸应力和硬度增大,耐老化性能得以改善。NBR用量的增加使得FHVBR/NBR共混胶对不同频率下的微波吸收能力增强,共混胶的电阻率下降,导电性增强。然而,NBR用量增加导致共混胶的拉伸强度略有下降。     

Properties of ASA/SAN/NBR ternary blends: effect of AN content in NBR

Abstract

Nitrile–butadiene rubbers (NBRs) with different acrylonitrile (AN) contents were used to toughen acrylonitrile–styrene–acrylic terpolymer/styrene–acrylonitrile copolymer (ASA/SAN) blends. The properties of the ASA/SAN/NBR ternary blends were investigated via dynamic mechanical analysis, heat distortion temperature, Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). The effects of AN content in NBR on physical properties, heat resistance and morphology of the ternary blends were studied. Heat distortion temperature of the blends decreased with increasing AN content of NBR. The impact strength reached the maximum value when 20 phr NBR with 26 wt-%AN content was added. Images (SEM) were in accordance with results of mechanical properties.     

Physical properties of polyamide 6/H‐NBR blends and the effects of dynamic vulcanization on them

Polyamide 6 (PA 6) and hydrogenated nitrile rubber (H‐NBR) were blended with various blend ratios in a brabender plasticoder at 240°C/100 rpm. The processing characteristics with a mixing torque of the blends were investigated. The effect of the blend ratio on physical properties such as tensile strength, Young's modulus, elongation at break, permanent set, hardness, and swelling behavior of blends was analyzed. Most mechanical properties were found to decrease with an addition of H‐NBR. The morphology of the blends was observed, and the results show a two phase system where the component with high proportions exists as a continuous phase. A cocontinuous phase was observed in blend ratios of 50/50 and 40/60. Dynamic mechanical properties were observed to study a viscoelastic property of the blends. In addition, the effect of dynamic vulcanization with peroxide on physical properties was studied, and the influence of peroxide on PA 6 was also examined. It was found that the peroxide can have an effect on PA 6 as well as act as a crosslinker to H‐NBR. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Compatibilization of nitrile‐butadiene rubber/ethylene‐propylene‐diene monomer blends by mercapto‐modified ethylene‐vinyl acetate copolymers

Mercapto‐modified ethylene‐vinyl acetate (EVASH) has been employed as a reactive compatibilizing agent for nitrile‐butadiene rubber (NBR)/ethylene‐propylene‐diene monomer (EPDM) blends vulcanized with a sulfur/2,2′‐dithiobisbenzothiazole (MBTS) single accelerator system and a (sulfur/MBTS/tetramethylthiuram disulfide (TMTD) binary accelerator system. The addition of 5.0 phr EVASH resulted in a significant improvement in the tensile properties of blends vulcanized with the sulfur/MBTS system. In addition to better mechanical performance, these functionalized copolymers gave rise to a more homogeneous morphology and, in some cases, better aging resistance. The compatibilization was not efficient in blends vulcanized with the S/MBTS/TMTD binary system, probably because of the faster vulcanization process occurring in this system. The good performance of these EVASH samples as compatibilizing agents for NBR/EPDM blends is attributed to the higher polarity of these components that is associated with their lower viscosity. Dynamic mechanical analysis also suggested a good interaction between the phases in the presence of EVASH. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1404–1412, 2004     

PP/EVA共混物的动态硫化研究

研究了动态硫化对聚丙烯/乙烯-醋酸乙烯酯共聚物(PP/EVA)共混物的性能和结构的影响。结果表明:动态硫化使PP/EVA共混物的力学性能(尤其是韧性)获得显著提高;通过对交联剂BIPB用量和助硫化剂S用量的合理控制可制得综合性能优异的PP/EVA动态硫化共混物;动态硫化可细化分散于PP基体中的EVA颗粒粒径,改善EVA的分散效果。最终制得的抗冲PP料主要性能均达到或超过国外同类产品水平。     

Thermoplastic elastomeric blend of nitrile rubber and poly(styrene‐co‐acrylonitrile). I. Effect of mixing sequence and dynamic vulcanization on mechanical properties

The effects of dynamic vulcanization and blend ratios on mechanical properties and morphology of thermoplastic elastomeric (TPE) compositions, based on blends of nitrile rubber (NBR) and poly(styrene‐co‐acrylonitrile) (SAN), were studied. The TPE composition prepared by adding a rubber‐curatives masterbatch to softened SAN yields higher mechanical properties than that prepared by adding curatives to the softened plastic–rubber preblend. The blends having a higher rubber–plastic ratio (60 : 40 to 80 : 20) display thermoplastic elastomeric behavior, whereas those having a higher plastic–rubber ratio (50 : 50 to 90 : 10) display the behavior of impact‐resistant plastics. DSC studies revealed that NBR and SAN are thermodynamically immiscible. SEM studies of the thermoplastic elastomeric compositions show that SAN forms the matrix in which fine particles of NBR form the dispersed phase. It was further confirmed by dynamic mechanical thermal analysis. Dynamic vulcanization causes a decrease in the size of dispersed particles and improvement in mechanical properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1976–1987, 2003     

Influences of the phenolic curative content and blend proportions on the properties of dynamically vulcanized natural rubber/acrylonitrile–butadiene–styrene blends

The vulcanization of natural rubber (NR)‐blended acrylonitrile–butadiene–styrene (ABS) was carried out with a phenolic curing agent by a melt‐mixing process. The NR compound was first prepared before blending with ABS. The effects of the phenolic curative contents (10, 15, and 20 phr) and blend proportions (NR/ABS ratio = 50 : 50, 60 : 40, and 70 : 30) on the mechanical, dynamic, thermal, and morphological properties of the vulcanized NR/ABS blends were investigated. The tensile strength and hardness of the blends increased with increasing ABS content, whereas the elongation at break decreased. The strength property resulting from the thermoplastic component and the vulcanized NR was an essential component for improving the elasticity of the blends. These blends showed a greater elastic response than the neat ABS. The thermal stability of the blends increased with increasing ABS component. Scanning electron micrographs of the blends showed a two‐phase morphology system. The vulcanized 60 : 40 NR/ABS blend with 15‐phr phenolic resin showed a uniform styrene‐co‐acrylonitrile phase dispersed in the vulcanized NR phase; it provided better dispersion between the NR and ABS phases, and this resulted in superior elastic properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42520.     

Mechanical properties and microstructure of acrylonitrile–butadiene rubber vulcanizates reinforced by in situ polymerized phenolic resin

The phenolic resin (PF) was incorporated into acrylonitrile–butadiene rubber (NBR) vulcanizates by in situ polymerization during the vulcanization process. It was found that the tensile strength, tearing strength, and tensile strength (300% elongation) could be considerably enhanced 59.4, 80.2, and 126.4%, respectively, at an optimum PF content of only 15 phr, but the elongation at break and shore A hardness were only slightly affected on the basis of silica‐reinforced NBR vulcanizates. A systematic study of the PF structure formed within the NBR matrix using various experimental schemes and procedures has revealed that the PF resin would form the localized discontinuous three‐dimensional interconnected network structures in the NBR matrix. The substantial reinforcement of PF on the mechanical properties of vulcanized NBR were attributed to the morphology, high flexibility, and moderate stiffness of the PF phases and their excellent bonding with rubbers through “rubber to rubber” and interface layer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Preparation and properties of PC/SAN alloy modified with styrene‐ethylene‐butylene‐styrene block copolymer

A polycarbonate (PC)/ poly (styrene‐co‐acrylonitrile) (SAN) alloy modified with styrene‐ethylene‐butylene‐styrene (SEBS) block copolymer was prepared and the influence of SEBS content, PC content, and types of modifier on Izod notched impact strength, tensile strength, flexural strength, and Vicat softening temperature was studied. The results showed that the addition of SEBS could obviously increase the Izod notched impact strength and the elongation at break and decrease the tensile and flexural strength and Vicat softening temperature. PC/SAN alloy modified with SEBS had better mechanical properties than the PC/SAN alloy modified with ABS. DSC analysis and SEM photographs revealed that the SEBS was not only distributed in the SAN phase but also distributed in PC phase in a PC/SAN/SEBS alloy while the ABS was mainly distributed in SAN phase in a PC/SAN/ABS alloy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

DMA analysis of the damping of ethylene–vinyl acetate/acrylonitrile butadiene rubber blends

The mechanical and damping properties of blends of ethylene–vinyl acetate rubber (VA content > 40% wt) (EVM)/acrylonitrile butadiene rubber (NBR), with 1.4 phr BIPB [bis (tert‐butyl peroxy isopropyl) benzene] as curing agent, were investigated by DMA and DSC. The effect of chlorinated polyvinyl chloride (CPVC), silica, carbon black, and phenolic resin (PF) as a substitute curing agent, on the damping and mechanical properties of EVM/NBR blends were studied. The results showed that 10 phr CPVC did not contribute to the damping of EVM700/NBR blends; Silica could dramatically improve the damping of EVM700/NBR blends because of the formation of bound rubber between EVM700/NBR and silica, which appeared as a shoulder tan δ peak between 20 and 70°C proved by DMA and DSC. This shoulder tan δ peak increased as the increase of the content of EVM in EVM/NBR blends. The tensile strength, modulus at 100% and tear strength of the blend with SiO₂ increased while the elongation at break and hardness decreased comparing with the blend with CB. PF, partly replacing BIPB as the curing agent, could significantly improve the damping of EVM700/NBR to have an effective damping temperature range of over 100°C and reasonable mechanical properties. Among EVM600, EVM700, and EVM800/NBR/silica blend system, EVM800/NBR/silica blend had the best damping properties. The EVM700/NBR = 80/10 blend had a better damping property than EVM700/NBR = 70/20. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Morphology development by reactive compatibilisation and dynamic vulcanisation of nylon6/EPDM blends with a high rubber fraction

Binary nylon6/rubber blends with 50 or 60 weight percent of an EPDM rubber exhibit co-continuous morphologies and thereby relatively poor mechanical properties. This paper describes methods to develop nylon6/EPDM blends with a high amount of finely dispersed rubber particles embedded in a nylon matrix. Using a suitable compatibiliser and by slightly crosslinking the rubber phase during melt-mixing, it was possible to disperse up to 60 wt% rubber in the nylon matrix and to improve the mechanical properties markedly. These materials are called thermoplastic vulcanisates and exhibit good elastic properties with a thermoplastic processability. The influence of the compatibiliser, the crosslinking agent and the viscosity ratio rubber/thermoplastic on the blend phase morphology is investigated using transmission electron microscopy. It was found that the viscosity ratio rubber/nylon plays a crucial role in order to achieve a nylon6/rubber TPV with a fine rubber dispersion. The viscosity of the nylon phase should be low enough to shift the phase inversion towards higher rubber content. On the other hand, if the viscosity of the nylon is too low, a coarse blend morphology was achieved resulting in poor mechanical properties.     

The phase inversion and morphology of nylon 1010/polypropylene blends

Noncompatibilized and compatibilized blends of nylon 1010/PP blends having five different viscosity ratios were prepared by melt extrusion. Glycidyl methacrylate-grafted-polypro-pylene (PP-g-GMA) was used as the compatibilizer to enbance the adhesion between the two polymers and to stabilize the blend morphology. The effect of the viscosity ratio on the morphology of nylon 1010/polypropylene blends was investigated, with primary attention to the phase-inversion behavior and the average particle size of the dispersed phase. The relationship between the mechanical properties and the phase-inversion composition was investigated as well. Investigation of the morphology of the blends by microscopy indicated that the smaller the viscosity ratio (ηpp/ηpa) the smaller was the polypropylene concentration at which the phase inversion took place and polypropylene became the continuous phase. The compatibilizer induced a sharp reduction of particle size, but did not have a major effect on the phase-inversion point. An improvement in the mechanical properties was found when nylon 1010 provided the matrix phase. © 1996 John Wiley & Sons, Inc.     

硫化剂PDM对NBR／CM共混物性能的影响

研究了N,N′-间苯撑双马来酰亚胺（PDM）对丁腈橡胶（NBR）/氯化聚乙烯（CM）共混物性能的影响。结果表明,随着PDM用量增加,NBR/CM共混物的正硫化时间（t90）缩短,硫化速度[1/（t90-t10）]增大,硫化程度（MH-ML）增加;共混物的松弛时间变短,胶料交联密度增大;当硫化剂PDM用量为1.2～2.0份时,共混物具有较好的物理性能。另外红外谱图的变化也充分说明助交联剂PDM打开分子链上的双键参与了CM与NBR的交联反应。     

Effect of butyl rubber type on properties of polyamide and butyl rubber blends

Polyamide‐12 was blended with butyl rubber, bromobutyl rubber, and chlorobutyl rubber with and without a sulfur curing system. Mechanical properties for dynamically vulcanized blends generally exceed those made with no vulcanization. Chlorobutyl‐containing blends prepared by dynamic vulcanization have higher tensile strength and elongation at break values in comparison to those made from other butyl rubbers. For a variety of polyamide/rubber blends made by dynamic vulcanization, there is very little effect of rubber percentage unsaturation and Mooney viscosity on the mechanical properties of the blends. In chlorobutyl‐containing blends prepared by dynamic vulcanization, the swelling index values attributed to the rubber portion decrease as rubber content decreases, and it is likely that the polyamide phase completely surrounds the rubber particles at compositions exceeding approximately 25% polyamide. Swelling index results can be correlated with elongation at break values for similar blends. The results of differential scanning calorimetry suggest that the polyamide phase is not a neutral component in high shear mixing with butyl rubbers with or without curing agents. Rheological studies indicate strong non‐Newtonian behavior for all blends of polyamide‐12 with butyl rubbers. Scanning electron microscopy on polyamide‐12/butyl rubber blends indicates compatibility for butyl rubbers in the order of chlorobutyl > bromobutyl > butyl rubber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1423–1435, 2004