摘要
用悬浮接枝共聚合法合成了乙烯／1-丁烯共聚物（PEB）与甲基丙烯酸甲酯（MMA）／N烯腈（AN）的接枝共聚物（PEB-g-MAN），并用其增韧苯乙烯／丙烯腈共聚物（SAN）。研究了SAN／PEPrg-MAN共混物的力学性能、增韧机理和相结构。结果表明：PEB-g-MAN是SAN树脂的优良增韧剂，当PEB用量为25％时，SAN／PEB-g-MAN的缺口冲击强度达63．3kJ／m^2，约为SAN树脂的60倍。SAN／PEB-g-MAN共混物在PEB含量为15％～20％时发生脆韧转变。脆韧转变前、脆韧转变过程中和脆韧转变后的冲击断面形态的SEM分析表明，共混物的增韧机理先是裂纹支化终止和空穴化，随后为高度空穴化，再为基体剪切屈服兼空穴化，最后转变为空穴化为主，剪切屈服为辅。TEM分析表明，PEB均匀分散于SAN连续相中，两相界面模糊，具有良好的相容性，且随着PEB含量的增加，共混物的相结构由“海-岛”结构转变为“双连续相”结构。
PEB-g-MAN, synthesized by suspension grafting copolymerization of methyl methacrylate and acrylonitrile onto PEB, was blended with styrene-acrylonitrile copolymer （SAN）. The mechanical properties, phase structure, and toughening mechanism of the SAN/PEB-g-MAN blends were studied using SEM and TEM. The notched impact strength of the blends （25%PEB） reached 63.3 kJ/m^2, which was nearly 60 times that of neat SAN. When the content of PEB was between 15 %～20 %, a brittle ductile transition was observed. TEM and SEM showed that SAN/ PEB-g-MAN were partially compatible. When the PEB content was low, the toughening mechanism of the blends was crack branching and termination with slight cavitation. As the PEB content increasing, the toughening mechanism shifted to extensive cavitation, and further to shear yielding accompanied by cavitation.
出处
《中国塑料》
CAS
CSCD
北大核心
2009年第10期40-44,共5页
China Plastics
