内循环撞击流反应器中聚丙烯固相接枝共聚改性研究

Solid phase graft copolymerization of PP in the internal circulating impinging stream reactor

在内循环撞击流反应器中对固相接枝共聚法制备马来酸酐(MAH)接枝改性的聚丙烯过程进行了研究,内容主要包括两部分:其一为冷态实验,考察撞击流反应器中锥底至中心导管间距、气体流量对PP颗粒循环的影响,结果表明,随着空气流量、锥底与下加速管间距的增加,撞击流反应器中颗粒循环量先增后降,存在最大值,空气流量为8.0～12.0m3/h、间距为30～35mm时较合适;其二为热态实验,考察了各种不同的反应条件对MAH在PP上的接枝率的影响。结果表明,接枝时间增加,接枝率增加,60～75min后基本趋于一定值;接枝温度升高,接枝率增加,115℃时达到最大值;单体浓度增高,接枝率增加;减小聚丙烯颗粒,有利于提高接枝率。

Polypropylene-maleic anhydride graft copolymers (MAH-g-PP) were produced utilizing the technique of solid phase graft copolymerization in the internal circulating impinging stream reactor (ISR). The study included two parts: (1) the cool model experiments, in which the effects of the distance between the bottom of the cone and the center tube in ISR and the air flow rate on the circulation of PP particles were investigated, by which the optimal structural parameters and operation conditions were obtained; (2) the thermal model experiments, in which the effects of several operation conditions on the degree of graft of MAH on PP particles were studied. The results of cool model experiments showed that the circulation of PP particles in the ISR increased first and then decreased with the increases of the air flow rate and the distance between the bottom of the cone and the center tube, and the ranges of the air flow rate 8.0～12.0 m^3/h and the distance 30～35 mm were recommended; The results of thermal model experiments gave the optimal operations: (1) the operation time 60～75 min, (2) the operation temperature 115 ℃. The experiments also showed that the graft degree would increase with increasing the concentration of MAH monomer and decreasing the PP particles' diameter.