悬浮法PEB-g-MAN/SAN共混物的热性能与耐老化性能研究

用悬浮接枝共聚法制备了乙烯-1-丁烯共聚物（PEB）与甲基丙烯酸甲酯和丙烯腈共聚物的接枝共聚物（PEB-g-MAN），并用其增韧苯乙烯-丙烯腈共聚物（SAN）。用动态力学分析、热重分析、人工气候老化和热氧老化试验等方法研究了PEB-g-MAN/SAN共混物的热性能与耐老化性能。结果表明，PEB-g-MAN/SAN共混物的PEB组分和SAN组分的玻璃化转变温度（Tg）之差明显低于PEB弹性体与SAN树脂的Tg之差，表明PEB-g-MAN与SAN树脂具有良好的相容性；PEB-g-MAN/SAN共混物的热稳定性明显优于SAN树脂，耐气候老化黄变性能和热氧老化后缺口冲击强度保持率明显优于丙烯腈-苯乙烯-丁二烯共聚物（ABS），而热氧老化后的拉伸、弯曲强度则稍逊于ABS。

Thermal Performance and Aging Properties of the PEB-g-MAN/SAN Blends Synthesized by Suspension Polymerization

PEB-g-MAN, synthesized by suspension grafting copolymerization of methyl methacrylate and acrylonitrile onto poly(ethene-co-1-butene) (PEB), was prepared to toughen styrene-acrylonitrile copolymer(SAN). Thermal performance and aging properties of the PEB-g-MAN/SAN blends were studied using DMA, TG/DTG, accelerated weathering aging, and thermal oxidative aging tests. DMA analysis showed that the differences of glass transition temperature (Tg) between PEB phrase and SAN phrase in PEB-g-MAN/SAN blends were apparently less than those between PEB elastomer and SAN resin, indicating PEB-g-MAN and SAN were partially compatible. TG/DTG results revealed that PEB-g-MAN/SAN blends performed better thermal stability than SAN resin. The aging test demonstrated the weatherability and yellowing resistance properties of PEB-g-MAN/SAN blends were much better than those of ABS. After thermal oxidation aging test, the retention of notched impact strength of PEB-g-MAN/SAN blends was superior to ABS, while the tensile strength and the flexural strength were slightly less than ABS.