Investigation of the Chain Structure and Thermal Property of Xylene Solubles of Impact Polypropylene Copolymers
LUO Hua-lin1, ZHAO Ying1*, WU Jin-guang2, WANG Du-jin1
1. Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China 2. College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
Abstract：Impact polypropylene copolymers (IPC) are in-situ blends of polypropylene homopolymer and ethylene-α-olefin copolymers formed in the reactor, which is a multiphasic complex material with isotactic polypropylene (iPP) as a matrix in which poly(ethylene-α-olefin) elastomeric copolymer is finely dispersed, and ethylene-α-olefin random copolymer (EPR) acts as an elastomer to improve the impact resistance properties of iPP at room temperature and low temperature. In the present, the content of xylene soluble is used to evaluate the content of EPR rubber phase in IPC. The content, the chain structure, and glass transition temperature (Tg) of EPR rubber are critical to the toughness of IPC. In the present report, Fourier transform infrared spectroscopy(FTIR), nuclear magnetic resonance (NMR) and differential scanning calorimetry(DSC) were utilized to study the comonomer content, chain structure and thermal property of xylene soluble of two IPC prepared by different catalysts. The results indicated that there are small amount of ethylene-propylene segmented copolymers containing short methylene sequence that is crystallizable in the xylene soluble in addition to the ethylene-propylene random copolymers. And the sequence length of crystallizable methylene group of ethylene-propylene segmented copolymers in these two kinds of xylene soluble is different. The random distribution degree of ethylene and propylene monomer in the ethylene-propylene copolymers in these two kinds of xylene soluble is similar. The xylene soluble with lower content of PPP sequence and higher content of ethylene monomer has lower Tg, which will benefit the improvement of impact resistance property of polypropylene.
罗华林1，赵 莹1*，吴瑾光2，王笃金1 . 抗冲共聚聚丙烯中二甲苯可溶物的链结构与性能研究 [J]. 光谱学与光谱分析, 2012, 32(12): 3363-3366.
LUO Hua-lin1, ZHAO Ying1*, WU Jin-guang2, WANG Du-jin1 . Investigation of the Chain Structure and Thermal Property of Xylene Solubles of Impact Polypropylene Copolymers. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2012, 32(12): 3363-3366.
