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离子改性对宽分子量分布聚丙烯黏弹性能影响OA北大核心CSTPCD

Effect of ion modification on viscoelasticity of broad molecular weight distribution polypropylene

中文摘要英文摘要

宽分子量分布聚丙烯(BMWDPP)PP1经离子改性剂处理后得到PP4.通过凝胶渗透色谱(GPC)与平板旋转流变、拉伸流变和熔体强度测试研究了PP1和PP4的分子结构与流变性能的变化.离子改性过程中的自由基诱发PP降解会降低BMWDPP的分子量大小及多分散性;虽未形成真正的长支链结构,但由于接枝在PP分子链上的金属盐之间靠离子相互作用造成"类长支链"效果,PP4可产生拉伸应变硬化现象;PP4因大分子量组分的降解削弱缠结及小分子量组分的降解增强塑化,导致黏弹性低于PP1.拉伸应变硬化对熔体强度增高的影响强于分子量降低对熔体强度削弱的影响,故PP4的熔体强度在不同的温度下皆高于PP1;在低温下呈现线形大分子量分子链PP特点,而在高温下呈现长支链PP特点.

PP4 was obtained through treating polypropylene with a wide molecular weight distribution(BMWDPP)PP1 using an ion modifier.The molecular structures and rheological properties of PP1 and PP4 were investigated by gel per-meability chromatography(GPC),plate rotational rheology,stretch rheology,and melt strength tests.The PP degrada-tion induced by free radicals reduced the molecular weight and polydispersity of BMWDPP.There was no real long branch chain structure generated due to the"long-like branched chain"effect of the ionic interaction between the metal salts on the PP chain segment.PP4 exhibits a stretch hardening phenomenon.The large molecular weight components could weaken the molecular entanglement,whereas the small molecular weight components could enhance the plasticiz-ing effect due to the degradation of PP4.This makes its viscoelasticity lower than that of PP1.The influence of stretch strain hardening on the enhancement of melt strength is stronger than the effect of molecular weight reduction on the weakening of melt strength.Therefore,the melt strength of PP4 is higher than that of PP1 at different temperatures.This indicated that the PP was featured with linear large molecular chains at low temperature and long branched chains at high temperature.

徐耀辉;唐伊文;郭鹏;吕明福

中石化(北京)化工研究院有限公司,北京 100013

化学工程

宽分子量分布聚丙烯离子改性黏弹性拉伸应变硬化熔体强度

broad molecular weight distribution polypropyleneion modificationviscoelasticitystretch hardeningmelt strength

《中国塑料》 2024 (001)

7-13 / 7

中国石油化工股份有限公司资助项目(421037-1)

10.19491/j.issn.1001-9278.2024.01.002

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