Solid-state modification of isotactic polypropylene (iPP) via grafting of styrene. I. Polymerization experiments
Solid-state modification of isotactic polypropylene (iPP) via grafting of styrene. I. Polymerization experiments
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DOI：
10.1002/app.12503
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发表时间：
2003-09-19
影响因子：
3
通讯作者：
Magusin, P
中科院分区：
文献类型：
--
作者：
Picchioni, F;Goossens, JGP;Magusin, P
将乙烯基单体以固态（即低于熔点）接枝到等规聚丙烯（iPP）上，与熔融或溶液接枝工艺相比具有多种优势，例如 iPP 的降解可以忽略不计并且无需任何溶剂。这种 iPP 改性或实际增容的 PP 共混物的最终性能取决于新聚合物在 iPP 基质中的分散情况，这在很大程度上由接枝程度与形成的游离均聚物的量控制。在本工作中，从单体聚合行为的角度研究了苯乙烯对 iPP 的固态改性。为了确定苯乙烯转化率和新形成的 PS 相沿 iPP 粉末颗粒半径的分布，通过红外 (FTIR) 和拉曼光谱对反应产物进行了表征。通过选择性溶剂萃取对反应产物进行分级，可以测定接枝效率 (Phi)。结果表明，除了接枝PS之外，还形成了另外两种类型的PS，即PP粉末孔中的游离PS均聚物和无定形PP相中的游离PS。 Phi 显示了作为进料过氧化物组成和进料速率的函数的最佳值。 (C) 2003 年 Wiley 期刊公司。
Grafting of vinyl monomers onto isotactic polypropylene (iPP) in the solid state, that is, below the melting point, displays several advantages over melt or solution grafting processes, such as negligible degradation of the iPP and absence of any solvent. The final properties of such iPP modifications or actually compatibilized PP blends are dependent on the dispersion of the new polymer into the iPP matrix, which is controlled to a large extent by the degree of grafting versus the amount of free homopolymer formed. In the present work, the solid-state modification of iPP by styrene has been investigated from the point of view of the monomer polymerization behavior. In order to determine the styrene conversion and the distribution of the newly formed PS phase along the radius of the iPP powder particles, the reaction products were characterized by infrared (FTIR) and Raman spectroscopy. Fractionation of the reaction products via selective solvent extraction allowed the determination of the grafting efficiency (Phi). It was shown that besides the grafted PS two additional types of PS are formed, that is, free PS homopolymer in the pores of the PP powder and free PS in the amorphous PP phase. Phi shows an optimum as a function of the feed peroxide composition and the feeding rate. (C) 2003 Wiley Periodicals, Inc.