三元乙丙橡胶/甲基丙烯酸锌复合材料的多重交联网络结构在拉伸压缩高温作用下的变化  

Multiple Crosslinking Network Changes of Zinc Methacrylate/EPDM Composites Under Tensile, Compression and High Temperatures

作　　者：张书槐 熊光超 席彤彤 王涛[1] 熊英[1] 郭少云[1] Shuhuai Zhang;Guangchao Xiong;Tongtong Xi;Tao Wang;Ying Xiong;Shaoyun Guo(Polymer Research Institute of Sichuan University,Sichuan Provincial Engineering Laboratory of Plastic/Rubber Complex Processing Technology,Chengdu 610065,China;Chengdu Macko Macromolecule Materials Co.,Ltd,Chengdu 610065,China)

机构地区：[1]四川大学高分子研究所四川省橡塑材料复合成型技术工程实验室 [2]成都迈科高分子材料股份有限公司,四川成都610065

出　　处：《高分子材料科学与工程》2022年第5期112-120,共9页Polymer Materials Science & Engineering

基　　金：国家自然科学基金重大项目子课题(51790501)。

摘　　要：反应性增强填料甲基丙烯酸锌(ZDMA)能够赋予三元乙丙橡胶(EPDM)硬度高、弹性大、内耗低、强度高及伸长率高等特点,但目前关于EPDM/ZDMA复合体系交联网络的组成以及在拉伸、压缩外力和高温环境的作用下,交联网络各组分所承载的功能方面还处于空白。因此,文中首先采用差示扫描量热分析和红外光谱测试证实了EPDM/ZDMA复合橡胶体系的交联网络主要由离子键交联网络和共价键交联网络两部分构成;然后采用溶胀平衡法及酸解抽提的方式详细研究了EPDM/ZDMA复合体系中离子键交联密度(v_(r1))和共价键交联密度(v_(r2))在拉伸和压缩应力作用下以及不同温度老化作用下的变化情况。结果表明,在拉伸应力作用下,体系的v_(r1)和v_(r2)均会出现不同程度的降低,ZDMA含量较低时,v_(r1)下降幅度较大,而ZDMA含量较高时,v_(r2)下降更多。在压缩应力作用的初期,v_(r1)和v_(r2)均发生了较大幅度的降低,但随着压缩时间延长,离子键交联网络仍在继续被破坏,而共价键交联网络则得以保持。EPDM/ZDMA复合体系的离子键交联网络在90~120℃之间存在一个敏感温度,低于90℃,24 h的老化对离子键交联密度几乎无任何影响,但当温度超过120℃后,24 h老化使其迅速降低。The reactive enhanced filler zinc methacrylate(ZDMA)can endow EPDM with characteristics of high hardness,high elasticity,low internal friction,high strength and high elongation at break.However,the specific compositions of EPDM/ZDMA and the structural changes of crosslinked network under the action of tensile,compression forces or high temperature are still not clear.Therefore,in this paper,differential scanning calorimetry(DSC)and Fourier transform infrared spectroscopy(FT-IR)were used to confirm that the total crosslinked network of EPDM/ZDMA composite is mainly composed of ionic crosslinked network and covalent crosslinked network.The changes of covalent bond crosslinking density(v_(r1))and ionic bond crosslinking density(v_(r2))in EPDM/ZDMA composite under tensile,compression force and aging at different temperatures were studied through the combination of swelling equilibrium and acid extraction method.The results indicate that both v_(r1) and v_(r2) decrease in different degrees under tensile stress.When ZDMA content is low,v_(r1) decreases greatly,while v_(r2) decreases more when ZDMA content is higher.At the initial stage of compression stress,both v_(r1) and v_(r2) decrease greatly,but with the extension of compression time,the ionic crosslinked network continues to be destroyed,while the covalent crosslinked network is maintained.The ionic bond crosslinking network of EPDM/ZDMA composite system has a sensitive temperature between 90℃and 120℃.When the temperature is lower than 90℃,the ionic bond crosslinking density has almost no effect after 24 h aging.However,when the temperature is higher than 120℃,the ionic bond crosslinking density decreases rapidly after 24 h aging.

关 键 词：三元乙丙橡胶 甲基丙烯酸锌 交联网络 拉伸应力 压缩应力 高温作用 

分 类 号：TQ333.4[化学工程—橡胶工业]