辐射增感交联的某些影响因素研究

A RESEARCH ON SOME FACTORS AFFECTING RADIATION SENSIBILIZED CROSS-LINKING

本文研究多官能团单体聚烯烃辐射交联增感的某些影响因素。首先研究了原料中不饱和结构的特征和数量对辐射增感交联的影响,结果表明,聚乙烯中亚乙烯基(RR’=CH_2)双键有加速交联的作用,对此种双键含量较高的聚乙烯,多官能团单体增感辐射交联的作用很小。其次探讨了抗氧剂对辐射交联的影响,选用阻位酚类(1010和3114)和小分子酚类(PG)抗氧剂进行实验,结果发现1010和3114在抗氧化降解的同时,阻滞聚乙烯的辐射交联反应,推迟凝胶化。而PG则相反,既有抗氧化降解的作用,又能促进聚乙烯的辐射交联。质谱分析给出,PG的辐解中间体为活泼自由基OH,它可以引发链自由基的产生,从而起到促进交联的作用。当加入多官能团单体时,观察到对含阻位酚类抗氧剂的聚乙烯有增感作用,而对含PG的聚乙烯则基本上不起作用,其原因可能与二者对链分子竞争反应有关。

The influence of unsaturation of various polyethylene on the radia-tion cross-linking, with and without polyfunctional monomers, was investigated.The results showed, that the suspended double-bonds of vinylidene has highercontribution to the radiation cross-linking. The polyethylene contained a bit moredouble-bonds possessed auto-sensibilized cross-linking action. The sensibilizing agentadded outside posses has very small influence on the acceleration of radiation cross-linking. The effects of three autioxidants (1010, 3114 and PG) on the radiation cross-linking efficiency of LDPE were studied. Experimental results showed, both 1010 and3114 decreased the amount of crosslinking at a given dose, contrarily, the PG increasedit. PG decomposed by radiation and produced OH radical which could accelerate theradiation cross-linking. When the polyfunctional monomer was added to the system, the radiation cross-linking of LDPE containing 1010 was accelerated. However, for sample cotaining PGthe sensibilizer exhibited very small influence on the radiation cross-linking.