【摘要】 采用酸凝固工艺和微生物凝固工艺分别制备了5种天然橡胶(NR)样品。为探讨5种NR样品在贮存过程中其特性的变化,采用加热的方法来模拟其贮存老化过程,并研究了5种NR样品的分子量、凝胶含量和塑性初值(Po)的变化规律。研究发现,加速贮存过程中,NR的分子量都有一定的增加趋势;盐酸羟胺的加入,可以抑制NR分子链的交联;随着加速贮存时间的延长,NR的凝胶含量增加;盐酸羟胺的加入,明显降低了NR的凝胶含量;NR的Po缓慢增加,其中微生物凝固的NR-2、NR-3和NR-4的Po较酸凝固的NR-1高,经盐酸羟胺处理的NR-5样品的Po最低。研究结果表明,微生物凝固NR的凝胶含量和Po较酸凝固NR高,盐酸羟胺的加入能够抑制NR分子链的交联、并降低凝胶含量和Po。更多还原

【Abstract】 Five kinds of natural rubbers (NR) were prepared by using acid-coagulation and microbial coagulation technology. In order to explore the properties change of the NR samples during storage,the aging processes were imitated by heating method and the variation of molecular weight, gel content and plasticity number were studied during accelerated storage. The researches showed that the molecular weight of NR samples played an increasing tendency during accelerated storage. With the addition of hydroxylamine hydrochloride,the crosslinking between molecular chain can be inhibited. With the prolonging of the accelerated storage,the gel contents decreased evidently and the plasticity numbers of NR samples increased slowly. With the addition of hydroxylamine hydrochloride, all the gel contents of NR samples increased. Besides, Po of NR-2, NR-3 and NR-4, which were prepared by microbial coagulation, was higher than NR-1 prepared, and Po of NR-5 treated with hydroxylamine hydrochloride was the lowest. The preliminary results above showed that the gel contents and the plasticity numbers of microbial coagulation were higher than acid-coagulation. Furthermore, with the addition of hydroxylamine hydrochloride,was the crosslinking between molecular chain will be inhibited, and gel contents and Po will be decreased.更多还原