天然橡胶的化学造粒工艺及性能研究

采用硫酸铝对天然胶乳进行化学造粒,研究了胶乳pH值、胶乳浓度、凝聚剂浓度等因素对化学造粒效果的影响,测试了产品的性能。结果表明,胶乳pH值为9.5～9.7,硫酸铝浓度为10%,硫酸铝用量为4.0～4.4%较宜；当天然胶乳pH较高、浓度较低时,都要适当提高硫酸铝用量。与酸凝天然橡胶相比,化学造粒天然橡胶的灰分含量、氮含量、P0较高,PRI较低；硫化胶的拉伸强度、定伸应力较高；热重分析表明,化学造粒天然橡胶热稳定性稍低于酸凝天然橡胶。;Natural Rubber was prepared by Chemical Granulation with Al2(SO4)2 as granulation agent, and the effects on granulation conditions have been investigated. The results showed that the optimum conditions were: the pH of natural rubber latex was 9.5～9.7, the quantity of Al2(SO4)2 was 4.0~4.4% and the mass concentration of Al2(SO4)2 was 10%. With concentration of natural rubber latex decreasing or the pH of that increasing,the quantity of Al2(SO4)2 should increased. Ash content, nitrogen content and Po of NR prepared by Chemical Granulation(NR-G) were all higher than that of acid coagulated natural rubber(NR-A), while PRI was lower. After being vulcanized,The tensile strength and stretching stres of NR-G was larger than that of NR-A