硅烷偶联剂对三元乙丙橡胶/硅橡胶并用胶性能的影响

研究硅烷偶联剂KH570和WD-10对三元乙丙橡胶(EPDM)/硅橡胶(MVQ)并用胶性能的影响。结果表明:偶联剂KH570能同时增强填料间、填料-橡胶间的相互作用,但不利于填料分散和降低胶料生热;偶联剂WD-10不能明显增强填料-橡胶间的相互作用,但惰性长链烷基的存在可以使填料的分散更为稳定;偶联剂KH570与WD-10并用时,能获得综合物理性能和耐高温老化性能优异的EPDM/MVQ耐高温复合材料。     

硅烷偶联剂对纳米二氧化硅/硅橡胶复合材料界面作用及性能的影响

利用单官能团偶联剂六甲基二硅氮烷(HMDS)及双官能团偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)分别对纳米Si O2进行表面改性,制备了改性Si O2/甲基乙烯基硅橡胶(MVQ)复合材料,研究了2种偶联剂对Si O2的改性效果,表征了改性Si O2在MVQ中的分散状态,且考察了2种偶联剂对复合材料结合胶、动态力学性能、交联密度及拉伸性能的影响。结果表明,HMDS和KH-570都能实现对Si O2改性接枝,且2种改性Si O2具有相同的摩尔接枝率;HMDS改性Si O2分散于基体中,且存在一定量团聚体,而KH-570改性Si O2的分散性较好,部分达到原生粒子级分散,颗粒与基体相容性提高;低应变条件下,Si O2经改性后,复合材料的储能模量(G')和损耗因子(tanδ)下降,且KH-570改性体系的G'低于HMDS改性体系,而tanδ高于HMDS改性体系;在高应变条件下,未改性与改性Si O2/MVQ复合材料的G'趋于一致,而KH-570改性体系的tanδ低于HMDS改性体系;改性Si O2/MVQ复合材料具有更高的交联密度和拉伸性能,且KH-570改性体系的交联密度和拉伸性能均高于HMDS改性体系。     

石英粉表面处理对硅树脂复合材料性能的影响

分别以六甲基二硅氮烷(HMDS)、γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH 570)、γ-(2,3-环氧丙氧)丙基三甲氧基硅烷(KH 560)、正十二烷基三甲氧基硅烷(WD-10)为改性剂,对2种粒径的石英粉进行表面改性,然后用于制备硅树脂复合材料。研究了石英粉用量、配比和改性剂种类对硅树脂复合材料性能的影响。结果表明,随着石英粉用量的增加,硅树脂复合材料的螺旋流动长度减小,当325目与3000目石英粉按质量比1∶1复配时材料弯曲强度最高。HMDS、KH 570、KH 560改性石英粉制得的硅树脂复合材料相较于未改性弯曲强度有所提升,吸水率下降。WD-10改性石英粉制得的硅树脂复合材料吸水率大幅下降,降幅最大为42. 91%。硅烷改性降低了石英粉表面极性,硅烷改性石英粉制备的硅树脂复合材料体积电阻率均升高,升幅最大为50%。     

三种硅烷偶联剂改性磷石膏在HDPE中的应用

使用三种硅烷偶联剂:3-氨基丙基三乙氧基硅烷(KH550)、3-(2,3-环氧丙氧)丙基三甲氧基硅烷(KH560)、3-(甲基丙烯酰氧)丙基三甲氧基硅烷(KH570)对磷石膏进行改性,将改性后磷石膏与高密度聚乙烯(HDPE)熔融共混制备改性磷石膏/HDPE复合材料。利用红外光谱测试改性磷石膏红外特征吸收,分析改性剂结构对接触角、吸油值的影响,通过扫描电镜考察改性磷石膏在HDPE基体中分散情况,并测试材料的力学性能。结果表明,改性磷石膏填料到HDPE基体后的弯曲和拉伸强度得到明显提升;经具有疏水端且长烷基链的KH560和KH570改性后的磷石膏在吸油值、接触角和基体中分散性都优于链端为氨基的KH550。     

偶联剂改性氧化铈提高硅凝胶的耐热氧性能

针对硅凝胶在使用过程中发生的变硬变脆等老化问题,本文以乙烯基硅油为基胶,含氢硅油为交联剂,氧化铝为填料制备了相应的硅凝胶弹性体。通过热重分析和马弗炉等温失重确定了硅凝胶基胶的热氧老化方式和氧化铈的抗热氧老化性能,并用三种不同类型的偶联剂对氧化铈进行了表面改性,探究了偶联剂改性氧化铈对硅凝胶耐热氧老化性能的影响。结果表明,添加偶联剂改性氧化铈可以明显提高硅凝胶的耐热性能,250℃老化8天,添加1%（质量分数）纳米氧化铈硅凝胶的拉伸强度与老化前相比增加了7.8倍,与此同时,添加1%（质量分数）KH560、6121和7707型偶联剂改性氧化铈的硅凝胶拉伸强度分别增加了2.5倍、4倍和4.7倍。综上,在老化前期,添加KH560偶联剂改性氧化铈的硅凝胶力学性能变化最小,抗热氧老化性能最佳。     

DMC补强EPDM/MVQ并用胶的性能研究

采用添加短纤维的不饱和聚酯（DMC）填充EPDM／基乙烯基硅橡胶（MVQ）并用胶。研究其物理性能和耐热老化性能。结果表明，添加DMC后。EPDM／MVQ并用胶的邵尔A型硬度和拉伸强度大幅提高，耐热老化性能较好，兼具EPDM，MVQ和DMC的优点。EPDM／MVQ并用胶的较优配方为：EPDM25，MVQ75，DMC80，白炭黑40，氧化锌5，防老剂D1，硫化剂DCP6，促进剂DM0．8。     

白炭黑对丁苯橡胶的补强作用

使用炭黑和白炭黑作填料可明显改善弹性网络的力学性能。力学性能在很大程度上与诸如体积分数、粒子的形状与尺寸以及填料-填料和填料-母体之间的相互作用等大量参数有关。但更重要的是填料粒子与橡胶母体之间的相互作用。导致聚合物链吸附到粒子表面的这种相互作用可以通过改变聚合物-填料界面性能来加以控制,在填料对聚合物粘附较差的情况下,如白炭黑填充的烃类橡胶,可用硅烷偶联剂来提高填料在弹性体母体中的分散作用,以改善两相间的粘附性能。偶联剂通常都含有双官能团分子,它们能在聚合物母体和填料表面间的界面处搭起分子桥。用这种方法,提高了橡胶-填料的粘附作用,从而增强了白炭黑的补强能力。对于硫黄硫化的非炭黑填料填充的胶料而言,硫基丙基三甲氧基硅烷（Dynasi-lan）是最有效的偶联剂之一。     

“胶乳共混法”制备天然橡胶／二氧化硅纳米复合材料及其性能

采用γ-甲基丙烯酰氧基丙基三甲氧基硅烷（KH570）改性纳米二氧化硅（SiO2）,然后通过乳液聚合接枝上聚甲基丙烯酸甲酯（PMMA）,再将其与甲基丙烯酸甲酯（MMA）改性的天然胶乳,通过胶乳共混法制备天然橡胶／二氧化硅纳米复合材料,结果显示,纳米二氧化硅表面接枝上了PMMA,二氧化硅在橡胶基体中分散良好,粒径在60～100nm之间,得到的胶膜力学性能有很大的提高。     

改善EPDM耐热性和加工性能的研究

研究了EPDM与甲基乙烯基硅橡胶(MVQ)共混,探讨了不同共混比和不同种类的增塑剂及用量对共混胶硫化特性、力学性能和老化性能的影响。结果表明,随着MVQ用量的增加,EPDM/MVQ共混胶的力学性能降低,老化性能增加,当EPDM/MVQ共混比为70/30时,综合性能最佳;共混胶中加入增塑剂,门尼粘度和交联密度均有所降低,添加20份石蜡油2280时,共混胶综合性能最好。     

相容剂对LDPE/MVQ并用胶热老化性能的影响

以低密度聚乙烯（LDPE）、相容剂、甲基乙烯基硅橡胶（MVQ）混炼胶为主要原料,加入自由基捕捉剂和硫化剂过氧化二异丙苯（DCP）,在双辊上将各组分进行熔融共混,通过平板硫化机将共混物硫化,制备出了LDPE／MVQ并用胶。本文重点研究了相容剂对LDPE／MVQ并用胶的力学性能和热老化性能的影响。结果表明,适量相容剂可以改善并用胶中LDPE和MVQ的相容性,提高材料的力学性能,而过多相容剂会阻碍LDPE与MVO共硫化反应的进行,降低并用胶机械强度和热老化性能。随着相容剂用量的增加,并用胶的拉伸强度、断裂伸长率和撕裂强度及热老化系数先增大后减小,其用量为15hpr时并用胶的综合性能最好。     

Oxidation‐grafting surface modification of waste silicone rubber composite insulator powder: Characterizations and properties of EPDM/modified waste powder composites

In order to broaden the applications of waste silicone rubber composite insulator powder (WSP), modified waste powder (WSP‐KH570) was prepared by a two‐step treatment process involving improved surface oxidation approach by using acidic H₂O₂ solution and subsequently grafting of KH570. Fourier transform infrared spectroscopy in the attenuated total reflection mode (FTIR‐ATR) analysis revealed the presence of KH570 on the powder surface. The result was confirmed by thermogravimetric analysis (TGA). Blends of ethylene propylene diene monomer (EPDM) with WSP‐KH570 were prepared. The effects of WSP‐KH570 on mechanical properties and thermal properties of the blends were investigated. The WSP‐KH570 showed an observed improvement in tensile strength and elongation at break of EPDM/WSP‐KH570 blends compared with corresponding compositions of EPDM/WSP blends. The TGA cure showed that EPDM filled with WSP‐KH570 had higher thermal stability at 210–380 °C than EPDM/WSP. Dynamic mechanical analysis indicated EPDM and WSP‐KH570 were better miscible with the blend ratio (90/10). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45438.     

Structure and mechanical properties of nanodispersed fibrous silicate‐reinforced ethylene–propylene–diene monomer nanocomposites

In this study, ethylene–propylene–diene monomer (EPDM)/fibrillar silicate (FS) nanocomposites were successfully prepared by mechanically blending EPDM with FS, which was modified by silane coupling agent KH570 containing methacryloxy group. The effects of silane content and modified FS on the dispersion of FS and mechanical properties of the composites were investigated. The impact of water in FS on mechanical properties of the composites was also evaluated. The results showed that modified FS could be dissociated into nanofibers dispersing evenly in the EPDM matrix by increasing substantially the loading of silane through the mechanical blending. The optimum loading level of silane coupling agent was up to 24 phr/100 phr FS. Silane KH570 could improve the dispersion of FS and strengthen nanofibers–rubber interfacial adhesion even at the loading of as high as 50 phr FS, making FS to exhibit excellent reinforcement to EPDM. Too much FS could not be completely dissociated into nanofibers, slowing down further improvement. The EPDM/FS composites exhibited the similar stress–strain behavior and obvious mechanical anisotropy with short microfiber‐reinforced rubber composites. With the increase in silane coupling agent and modified FS, the number of nanofibers increased because of the exfoliation of FS microparticles; thus, the mechanical behaviors would become more obvious. It was suggested that the free water in FS should be removed before mechanically blending EPDM with FS because it obviously affected the tensile properties of the composites. Regardless of whether FS was dried or modified, the EPDM/FS composites changed little in tensile strength after soaked in hot water. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis of silane‐grafted ethylene vinyl acetate copolymer and its application to compatibilize the blend of ethylene‐propylene‐diene copolymer and silicone rubber

Vinyltrimethoxysilane‐grafted ethylene vinyl acetate copolymer (EVA‐g‐VTMS) was synthesized and applied to compatibilize ethylene‐propylene‐diene copolymer (EPDM)/methyl vinyl silicone rubber (MVQ) blends. The silane‐grafting was successfully proved by differential scanning calorimetry, FTIR spectroscopy and XPS spectroscopy. The additive amount of the compatibilizer (EVA‐g‐VTMS) was optimized to be 10 phr (parts per hundred of rubber in weight) based on analysis of scanning electron microscopy, mechanical properties, aging properties, dynamic mechanical properties, rheological properties and thermal properties. Compared with the blend without EVA‐g‐VTMS, results show that the blend with 10 phr of EVA‐g‐VTMS exhibits the finest morphology. Tensile strength, elongation at break, modulus at 100% elongation, tear strength and TE index increase by 82.5%, 16.9%, 60.0%, 40.9%, and 41.9%, respectively. Dynamic mechanical analysis reveals storage modulus increase and glass transition temperatures of EPDM and MVQ move closer to each other. Rheological analysis shows a decrease in complex modulus and complex viscosity, and the processibility of the blend was improved. Furthermore, thermogravimetric analysis shows enhancement of thermal stability. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers     

分散剂和偶联剂对白炭黑填充硅橡胶性能的影响

研究锌皂分散剂、偶联剂KH-560及其并用对白炭黑填充硅橡胶性能的影响。结果表明,锌皂分散剂和偶联剂KH-560均能弱化填料网络结构,促进白炭黑的分散,减小胶料在低应变下的储能模量,且二者并用效果更佳;结合胶质量分数增大表明偶联剂KH-560和锌皂分散剂并用能够提高填料与硅橡胶间的相互作用;锌皂分散剂的加入明显缩短了胶料的正硫化时间,在保证操作安全的前提下,显著加快了硫化速率;偶联剂KH-560改性白炭黑体系中加入少量的分散剂,硫化胶的硬度、100%和300%定伸应力、拉伸强度呈增大趋势,拉断伸长率减小。     

Some interesting phenomena in silica‐filled HNBR with the addition of silane coupling agent

Hydrogenated nitrile rubber (HNBR)/silica nanocomposites were prepared by in‐situ modification dispersion technology, and the silane coupling agent γ‐methacryloxypropyl trimethoxy silane (KH570) was chosen to promote the interfacial strength between silica particles and HNBR matrix and further improve the dispersion of silica particles. Rubber Process Analyzer (RPA2000) was used to test the Payne effect of HNBR/silica compounds, from which some interesting phenomena were found: the Payne effect became stronger after KH570 was added to HNBR/silica compound at room temperature, which was a contrary result compared to SBR/silica system. However, after stored for a month at room temperature, the Payne effect weakened, which was contrary to the traditional phenomenon of storage hardening of filled rubber. All these results are related to filler–filler interaction and filler–rubber interaction. The modulus at small strain amplitude of HNBR/silica compound with KH570 gradually decreased with the increase of times of circulatory strain sweep but that of compound without KH570 had almost no change, which was explained by Fourier Transform Infrared (FTIR) results that the reaction between silica and KH570 almost completed at the test condition: 80°C and about 1 h. The effects of silane amount, heat‐treated temperature and time on the Payne effect of compounds and the mechanical properties of vulcanizates were also investigated. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

车用耐高温三元乙丙橡胶密封胶垫的研制

介绍了采用三元乙丙橡胶为主要原料,制备汽车水箱用耐高温密封胶垫.结果表明,当EPDM 100(质量份);硫化剂2～4;补强剂20～50;软化剂0～10;防老剂2～4;其它助剂10～12时,该混炼胶具有优异的耐热、耐水蒸气和压缩永久变形,可满足汽车水箱、暖风机等部件的使用要求.     

PP-硅橡胶-LLDPE三元共聚物的合成及性能研究

以聚丙烯(PP)为基体树脂,硅橡胶为增韧剂,线性低密度聚乙烯( LLDPE)为辅增韧剂,制备了一系列的PP/硅橡胶LLDPE的三元共聚物,考察了PP填充不同配比的硅橡胶共混物的力学性能.结果表明,随着硅胶含量不断的增加,样条的断裂伸长率,弹性模量,冲击强度逐渐增加,样条的拉伸强度随着硅胶的增加而逐渐减少;LLDPE的加入量为15％时,PP/硅橡胶/LLDPE的三元共混体系力学性能最佳;硅橡胶的加入量为20％时,PP/硅橡胶/LLDPE的三元共混体系具有良好的拉伸性能和冲击强度.     

Composites based on CB/CF/Ag filled EPDM/NBR rubber blends with high conductivity

For many applications of conductive rubbers, it is desirable to endow the conductive rubber with high conductivity at low conductive filler loading. In this work, composites based on ethylene‐propylene‐diene monomer (EPDM) rubber and nitrile‐butadiene rubber (NBR) were prepared using carbon blacks, carbon fibers, and silver powders as fillers. As the weight fraction of silver powder increased, the hardness of composites increased gradually while the tensile strength and elongation at break decreased. SEM revealed that the EPDM/NBR blends exhibited a relatively co‐continuous morphology. The differential scanning calorimetry (DSC) curves reported the EPDM/NBR rubber blends were incompatibility. The thermogravimetry (TG) studies showed that adding a small amount of silver powder could improve the thermal stability of composites. These conductive composites exhibited good electrical property. At room temperature, when the total volume fraction of fillers was 15.20%, the volume resistivity of EPDM/NBR blend was only 0.0058 Ω cm. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41357.     

The morphology and property of ultra‐fine full‐vulcanized acrylonitrile butadiene rubber particles/EPDM blends

A novel UFNBRP/EPDM blend was prepared by compounding ultra‐fine full‐vulcanized acrylonitrile butadiene rubber particles (UFNBRP) with ethylene–propylene–diene monomer (EPDM) matrix. The morphology, dynamic property, and curing property of the blend were discussed in detail. TEM and SEM observations showed that, no matter how high the blend ratio of UFNBRP to EPDM matrix was, UFNBRP particles always kept being in the dispersion phase because of its extremely high viscosity resulting from self‐crosslinking, but were not dispersed as nanosize units, as expected. Dynamic properties, illustrated by DMTA, further demonstrated that two phases exhibited two separate glass transition temperatures, indicating distinct phase separation and weak phase interaction. Rubber processing analyzer results showed that inorganic filler as well as UFNBRP particles in EPDM matrix formed a network and blocked the flow properties of the compound. At the same time, the introduction of UFNBRP particles evidently affected the vulcanization of EPDM, when sulfur was used as a vulcanizing agent, and improved the mechanical properties of EPDM. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3673–3679, 2006