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Elucidation of Static and Dynamic Properties of Highly Branched Polymers

阐明高度支化聚合物的静态和动态性能

基本信息

批准号：
14550844
负责人：
YAMAGISHI Tada-aki
金额：
$ 2.11万
依托单位：
Kanazawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14550844/
关键词：
Phenolic resin Highly branched polymer Dilute solution properties Conformation Methylene linkage pattern Dynamic birefringence measurement Stress optical coefficient Segment orientation mechanism 置換基効果ミセル状分子

项目摘要

Highly branched polymer was prepared by the condensation of phenol with paraformaldehyde in acetic acid using HC1 as catalyst. Linear polymer was prepared by the condensation of o-cresol with paraformaldehyde in acetic acid using HC1 as catalyst. The molecular weight dependence of intrinsic viscosity [η] and mean-square radius of gyration <S^2> for the highly branched and linear polymers were determined and the effect of side chain on the molecular conformation in solution was elucidated, respectively. For the linear polymer with lauroyl group, the phenolic main chain was aggregated in the center of molecule and the alkyl side chain was external to the molecule in n-octane. The conformation was like a micelle. On the other hand, the phenolic main and alkyl side chain coexisted and the conformation was extended in MIBK. For the highly branched polymer the effect of side chain on the conformation is not remarkable. This is due to the flexibility of linear polymer.A graft copolymer having … More poly(2-vinylpyridine) trunk and sixty-eight polystyrene branches was prepared by anionic coupling method. The trunk span between branching points was about two times wider than the Rouse segment size for linear polystyrene. Dynamic birefringence and dynamic viscoelastic measurements around Tg zone showed that the complex Young's modulus and the strain optical coefficient of the copolymer was similar to those of linear polystyrene. The stress optical coefficients for the rubbery and the glassy components, respectively, agreed with those for linear polystyrene, meaning that no indication of microphase separation was ideologically detected over a whole rang of frequencies studied. The effect of branching was not observed in the frequency dependence of the glassy component. In the rubbery zone, the mode observed at short times was attributed to motion of polystyrene branches, and the other mode at long times was related to the motion of poly(2-vinylpyridine) trunk. Although Mw of poly(2-vinylpyridine) was much higher than the molecular weight of entanglement strands of linear polystyrene, the rubbery plateau zone was not clearly observed, possibly due to inhibition ofentanglements by branching. Less

以苯酚和多聚甲醛为原料，在冰醋酸中，盐酸为催化剂，合成了高度支化的聚合物。以邻甲酚和多聚甲醛为原料，在冰醋酸中，以盐酸为催化剂进行缩合反应，合成了线性聚合物。测定了超支化和线型聚合物的特性粘数[η]和均方回转半径<S^2>与分子量的关系，阐明了侧链对溶液中分子构象的影响。对于含月桂酰基的线型聚合物，正辛烷中酚基主链聚集在分子中心，烷基侧链在分子外。构象类似胶束。另一方面，在MIBK中，酚基主链和烷基侧链共存，构象扩展。对于高度支化的聚合物，侧链对构象的影响不显著。这是由于线性聚合物的柔性。 ...更多信息采用阴离子偶联法制备了聚2-乙烯基吡啶主干和68个聚苯乙烯支链。分支点之间的主干跨度比线性聚苯乙烯的劳斯段尺寸宽约两倍。动态双折射和动态粘弹性测量表明，该共聚物的复杨氏模量和应变光学系数与线性聚苯乙烯相似。的橡胶和玻璃组分的应力光学系数，分别与线性聚苯乙烯，这意味着没有迹象表明微相分离的意识形态检测在整个范围内的频率研究。在玻璃组分的频率依赖性中没有观察到支化的效果。在橡胶区，在短时间内观察到的模式归因于聚苯乙烯支链的运动，而另一种模式在长时间内与聚（2-乙烯基吡啶）主干的运动有关。虽然聚（2-乙烯基吡啶）的Mw比线性聚苯乙烯的缠结链的分子量高得多，但没有清楚地观察到橡胶态平台区，可能是由于支化抑制了缠结。少