【摘要】 以未添加助剂的聚丙烯(PP)粉料为原料,三羟甲基丙烷三丙烯酸酯(TMPTA)为接枝单体,采用热引发熔融接枝的方法制备长链支化聚丙烯(LCBPP)。当支链分子量大于PP的临界分子量(Me=5 600)的2倍时,对流变性能有很大的影响,称为流变学长支链。研究了二硫化四甲基秋兰姆(TMTD)在熔融接枝体系中的调控作用。研究结果表明,加入TMTD后,单体的接枝量降低,但是支化效率提高。理论计算表明,在同样条件下加入TMTD后,改性样品的长支链频率由0.03升至0.34。更多还原

【Abstract】 Trimethylol propane triacrylate(TMPTA) and polypropylene(PP) powder without any additives were used to prepare long chain branched polypropylene by in situ heat-induction melt-grafting.The long chain branches of PP with molecular mass over twice the molecular mass between successive entanglements(>2Me) have dramatic effect on the rheological properties.The effect of tetramethylthiuram disulfide(TMTD) on the heat-induction melt-grafting was studied.It was found that the grafting degree of TMPTA decreased but the branching efficiency increased when TMTD was added to the system.According to the result of theoretic calculation,the branching frequency increased from 0.03 to 0.34 when TMTD was employed under the same conditions.更多还原