粉末天然橡胶的性能研究

研究粉末天然橡胶(PNR)的性能，并与酸凝天然橡胶(NR)进行对比。结果表明：与酸凝NR相比，PNR的灰分质量分数、氮质量分数、挥发分质量分数、塑性初值和塑性保持率较高，杂质质量分数、丙酮溶物质量分数和门尼粘度较低；PNR混炼胶的流动性较好，M_L稍低，M_H稍高，t_s1和t_s2较小，t₁₀、t₅₀和t₉₀较大，硫化速率较慢；PNR硫化胶的拉伸强度、300%和500%定伸应力较大，拉断伸长率较小。隔离剂的用量宜为2～3份。;The properties of powdered NR(PNR) were investigated，and compared with those of acid coagulated natural rubber (NR-a).The results showed that，compared with NR-a，the ash content，nitrogen content，volatile content，initial plasticity and plasticity retention index of PNR were higher，and the impurity content，acetone soluble content and Mooney viscosity were lower.Compared with NR-a，the PNR mix possessed higher M_H，t₁₀，t₅₀ andt₉₀，lowerM_L，t_s1 and t_s2，and had a lower curing rate.The tensile strength，the moduli at 300% and 500% elongation of PNR vulcanizate were higher than those of NR-a vulcanizate，but the elongation at break was lower.The optimum addition level of release agent was 2～3 phr