剪切和拉伸流场对动态硫化EPDM/PP的力学性能与结晶结构的影响

利用以拉伸流场为主的叶片挤出机(VE)和以剪切流场为主的双螺杆挤出机(TSE)分别制备了不同组分比的动态硫化三元乙丙橡胶/聚丙烯(EPDM/PP)热塑性弹性体。通过对2种流场作用下共混物的力学性能、结晶熔融行为以及晶体形貌和晶体结构的对比分析,研究了拉伸流场对动态硫化EPDM/PP结构与性能的影响。结果表明,与双螺杆挤出机相比,由于拉伸流场更好的分散混合效果,EPDM/PP热塑性弹性体中的PP相能在较低温度结晶,共混物中PP相的晶体尺寸更小,分布更均匀,EPDM相与PP相界面结合更好,共混物的力学性能得到了显著提高;拉伸流场对EPDM/PP热塑性弹性体中PP相的晶格结构无影响,但对PP的结晶度影响较大。     

EPDM/PP热塑性弹性体研究进展

对动态硫化EPDM /PP热塑性弹性体的研究作了简要回顾 ,介绍了动态全硫化制备EPDM /PP热塑性弹性体的方法 ,重点讨论在动态硫化中影响EPDM /PP热塑性弹性体的力学性能、流变性能、相态结构和结晶性能的一些因素     

动态硫化EPDM/PP热塑性弹性体

本文详细讨论了三种硫化体系对动态硫化EPDM／PP热塑性弹性体力学性能及加工性能的影响，并介绍了动态硫化EPDM／PP硫化体系的新进展。     

动态硫化EPDM/PP热塑性弹性体应力松弛的研究

从相态结构角度讨论动态硫化EPDM／PP共混物的应力松弛行为,并与纯PP以及静态硫化EPDM的应力松弛相比较,研究了制备工艺对动态硫化EPDM／PP共混物应力松弛的影响,结果表明,动态硫化EPDM／PP应力松弛主要由PP连续相决定的,EPDM分散相对共混物应力松弛有一定的影响。随橡塑化和软化剂用量的增加,EPDM／PP应力松弛明显降低,增大硫化剂用量,EPDM／PP应力松弛相对较小。     

NR／HDPE共混热塑性弹性体的结构与性能研究

用抽提法、流变仪、示差扫描量热仪、热重法、动态粘弹谱仪、扫描电镜等仪器研究了ＮＲ／ＨＤＰＥ共混热塑性弹性体（ＴＰＥ）的结构与性能。实验结果表明，动态和静态硫化共混物的交联程度相近。控制ＮＲ的交联程度可改善共混物的流动性。ＮＲ／ＨＤＰＥ共混热塑性弹性体中、ＨＤＰＥ结晶度则随ＮＲ的增加而略微降低。只要ＨＤＰＥ足以包裹胶胶粒子就就可以形成连续相。动态硫化增加了共混物中ＮＲ与ＨＤＰＥ相界面间的结合力。     

防水卷材用改性胶粉/EPDM/PP热塑性弹性体的制备与性能研究

以乙丙橡胶(EPDM)、胶粉和聚丙烯(PP)等为主要原料,采用共混的方法制备了改性胶粉/EPDM/PP热塑性弹性体,研究了胶粉的改性剂、充油EPDM用量和胶粉用量等对改性胶粉/EPDM/PP热塑性弹性体性能的影响。结果表明:橡胶再生剂RV2和酚醛树脂并用改性胶粉所制得的改性胶粉/EPDM/PP热塑性弹性体综合性能最优;使用7.5份充油EPDM所制得的弹性体综合性能最优;随着胶粉用量的增加,热塑性弹性体的综合性能下降,使用15份改性胶粉时性价比最高,同时满足国标GB/T 27789—2011要求。对微观结构进行分析,经过橡胶再生剂RV2和酚醛树脂改性后的胶粉与橡胶基体和PP间形成了良好的结合。     

AT/APP/ASO阻燃剂在EPDM/PP弹性体中的应用研究

采用动态硫化工艺,制备三元乙丙橡胶(EPDM)/聚丙烯(PP)热塑性弹性体,研究凹凸棒土(AT)、聚磷酸铵(APP)、氨基硅油(ASO)对弹性体力学性能和阻燃性能的影响。研究表明:添加5份AT的EPDM/PP弹性体力学性能最佳,AT的加入可提高EPDM/PP弹性体的阻燃性能;随着APP的用量增加,EPDM/PP弹性体的拉伸强度、撕裂强度和最大伸长率均下降,氧指数增大;随着ASO的用量增加,EPDM/PP弹性体的拉伸强度、撕裂强度下降,最大伸长率先上升后下降,氧指数增大。     

动态全硫化热塑性弹性体EPDM／PP拉伸蠕变行为的研究

Santoprene是当前颇具代表性的动态全硫化共混型热塑性弹性体EPDM/PP品种,其EPDM形成分散相,PP形成连续相。本文依据它的这种结构特征,引用高柳素夫模型,计算出模型中各单元的重量比、体积比和拉伸蠕变柔量,由此推论它的蠕变行为。     

动态硫化EPDM／PP热塑性弹性体动态力学性能的研究

应用动态热力学分析仪测定了动态硫化EPDM／PP共混物的动态力不宪为,Tg峰的变化,表明P的非晶部分与EPDM具有部分互溶性,同时讨论了共混物动态模量的特点,研究了不同橡塑比,硫化剂和软化剂用量对动态硫化EPDM／PP共混物动态力学性能的影响。     

轿车传动轴用EPDM/PP热塑性弹性体的应用开发研制

1997年12月湖北大学承担了国家高技术研究发展计划(863计划)“轿车传动轴用EPDM/PP热塑性弹性体的应用开发”课题研究。该项目是以三元乙丙橡胶(EPDM)和聚丙烯(PP)为主要原料,采用完全硫化和物理共混技术,制得具有特定性能指     

动态光交联法制备PP/EPDM热塑性弹性体的力学及热性能

采用动态光交联法制备了PP/EPDM热塑性弹性体。动态力学热分析(DM TA)和扫描电子显微镜(SEM)及力学性能测试表明:动态光交联能明显提高PP与EPDM间的相容性,从而显著提高PP/EPDM热塑性弹性体的拉伸性能和缺口冲击强度。并结合DM TA、差热扫描量热仪(DSC)等手段,证实了动态光交联过程中产生了少量的接枝共聚物PP-g-EPDM。     

Use of Differential Scanning Calorimetry (DSC) in the Characterization of EPDM/PP Blends

New polyolefinic thermoplastic elastomers based on the ethylene–propylene-diene monomer (EPDM) and polypropylene (PP) containing an EPDM elastomer of the last generation (Nordel NDR 47130), obtained by polymerization in the gaseous phase with metallocene catalysis, were prepared and characterized. The melting and crystallization behavior of these blends was investigated by differential scanning calorimetry. It is observed that the melting temperature, crystallization temperature, and crystallinity degree increase with an increase of PP loading. The influence of the blend composition on the physico-mechanical characteristics was discussed using statistical processing of the experimental data. Two compatibilizing procedures were utilized to improve the physico-mechanical characteristics of the samples: an addition method using different compatibilizing agents and dynamical vulcanization with three types of crosslinking systems. Significant improvements of the tensile strength and tear strength were noted by dynamic crosslinking, and the best results were obtained using a crosslinking system based on phenolic resin and tin chloride.     

动态交联热塑性弹性体增韧聚丙烯合金

用动态交联方法制备聚烯烃热塑性弹性体（ＴＰＯ）增韧聚丙烯，制备了具有低温冲击性能良好、综合力学性能比较均衡的聚丙烯合金。同时，研究了ＴＰＯ组成、工艺及基体组成与ＴＰＯ增韧聚丙烯共混物力学性能的关系。并通过差热扫描量热计和扫描电镜考察了共混物的形态结构。     

EPDM动态硫化增韧PP的性能和形态研究

采用羟甲基叔丁基酚醛树脂及２,５－二甲基－２,５－二叔丁基过氧基己烷／硫黄作交联剂,研究了三元乙丙橡胶动态硫化对增韧聚丙烯性能的影响。实验证实,随酚醛树脂用量增加共混物的抗冲韧性显著提高,但流动性明显下降。过氧化物既能有效硫化橡胶,又能使聚丙和解,从而得到高韧性和高流动性的共混物。扫描电镜分析表明,交联剂用量增加,共混物中橡胶相粒径显著减小,这归因于橡胶相的交联和在橡界面形成接枝或嵌段共聚物。     

Scanning electron microscopy studies on tensile failure of thermoplastic elastomers from polypropylene-natural rubber blends

The tensile properties of thermoplastic polypropylene [pp]-natural rubber [NR]blends have been evaluated with special reference to the effect of blend ratios and dynamic cross-linking of the elastomer phase. The effects of silica filler and silane coupling agent on the tensile properties of the 30:70 PP:NR blend have also been studied. Analysis of the stress-strain curves and scanning electron microscopic examination of the tensile fracture surfaces of the blends have been used to correlate the test results on tensile properties.     

Highly toughened polypropylene/ethylene–propylene-diene monomer/zinc dimethacrylate ternary blends prepared via peroxide-induced dynamic vulcanization

Polypropylene (PP)/ethylene–propylene-diene monomer (EPDM)/zinc dimethacrylate (ZDMA) blends with remarkable toughness and extensibility were successfully prepared via peroxide dynamical vulcanization. A unique structure with the EPDM particles surrounded by a transition zone containing numerous polymerized ZDMA (PZDMA) nano-particles was observed for the first time by using transmission electron microscopy (TEM) examination, which contributed to the dramatically increase of Izod impact strength. Dynamic mechanical analysis (DMA) confirmed that the possible PZDMA graft products resulted from peroxide dynamical vulcanization improved the compatibility between EPDM and PP phases. The specific morphology of the PP/EPDM/ZDMA blends indicated that ZDMA can lead to size reduction and good distribution uniformity of the crosslinked rubber particles and the increase of adhesion between PP matrix and EPDM phases during deformation. The synergic effect of the increase in the effective volume of the EPDM phase, the improved compatibility and adhesion between EPDM and PP phases and the deformation of those fine rubber particles is believed to result in the remarkable high toughness and extensibility of the PP/EPDM/ZDMA blends. Particularly for the PP/EPDM ratio of 70/30, the PP/EPDM/ZDMA (70/30/9, w/w/w) ternary blends with the Izod impact strength nearly 2 times higher than PP/EPDM (70/30, w/w) binary blends and 15–20 times higher than PP are achieved; besides, the elongation at break of PP/EPDM/ZDMA ternary blends is 4–5 times higher than that of PP/EPDM binary blends.     

采用β成核动态硫化PP/EPDM共混物增韧聚丙烯

采用β成核的动态硫化iPP/EPDM共混物即热塑性硫化胶(TPV)改性聚丙烯,并与通用增韧剂聚烯烃弹性体(POE)、三元乙丙橡胶(EPDM)增韧聚丙烯进行比较,考察了增韧体系的力学性能、热性能和相形态.结果表明,随增韧剂含量的增加,增韧体系的拉伸屈服强度和弯曲模量均有所下降,而冲击强度提高.TPV改性体系的强度、模量和...     

Effect of crosslinking on morphology and phase inversion of EPDM/PP blends

This study investigates the effect of cross-linking on morphology and phase inversion of EPDM/PP blends. Several EPDM/PP blends without and with cross-linking agent were prepared in a Haake batch mixer under constant conditions. The morphology was studied by electronic microscopy (SEM and TEM), and cross-linking was followed by EPDM gel content and swelling. The results showed that the position of the phase inversion region is essentially governed by composition, being independent of the viscosity ratio of the EPDM/PP blend. The TPVs’ morphology of the EPDM/PP blend, with 70 and 50 wt% of PP, consists of EPDM cross-linked particles dispersed in the PP matrix. For EPDM-rich composition (30 wt% of PP), the TPVs’ morphology appears to be co-continuous. Even though dynamic vulcanisation of the rubber phase always improves the dispersion of the EPDM phase, complete phase inversion (from fully dispersed PP in the EPDM matrix to EPDM fully dispersed in the PP matrix) was achieved only with low viscosity EPDM.