超临界CO2协助马来酸酐对聚丙烯的接枝共聚

利用超临界流体插嵌技术协助苯乙烯和马来酸酐共单体对聚丙烯膜进行接枝改性。在制备过程中采用“两步法”,有利于研究超临界CO2的溶胀、渗透和携带作用,并且能够控制成本。临界CO2的插嵌压力、插嵌温度以及引发剂浓度是影响接枝率的主要因素。在压力10 MPa、温度42℃条件下,接枝率具有极大值,约为4.7%。对接枝前后聚丙烯膜的FT-IR、DSC、SEM表征,进一步证明了共单体确实接枝在聚丙烯膜基质上,并且随着接枝率的提高,接枝聚丙烯膜的表观结晶度和熔点均下降。

Graft Copolymerization of Polypropylene by Maleic Anhydride with the Assistant of Supercritical CO2

The polypropylene （PP） film is grafted by comonomers consist of maleic anhydride （MAH） and styrene （St） with the assistant of supercritical CO2. The＂two- step method＂used in this process is favor of investigating the swelling, penetrating and carrying actions of supercritical CO2, as well as controlling the cost. The factors which influence the grafting ratio mainly include the concentration of initiator, pressure and temperature. Under the condition of 10 MPa,42 ℃, the grafting ratio reaches a maxium, about 4.7 %. The grafted PP film is characterized by FT - IR, DSC, SEM. It shows that the graft copolymerization really take place on the PP chains. In addition, the melting point and apparent crystallinity decrease with a increase in grafting ratio.