环保型促进剂二苄基二硫代氨基甲酸锌对天然胶乳硫化胶膜性能的影响

Effects of environment-friendly accelerator zinc dibenzyl dithiocarbamate on properties of vulcanized natural rubber latex film

选择二苄基二硫代氨基甲酸锌(ZBDC)、二异丙基黄原聚硫、二硫化四苄基秋兰姆作为天然胶乳(NRL)的硫化促进剂,采用正交试验确定了NBL的硫化配方及最佳工艺,对比了促进剂ZBDC及传统促进剂二乙基二硫代氨基甲酸锌(ZDC)对NRL硫化胶膜性能的影响,考察了贮存时间对NRL硫化程度及硫化NRL黏度、机械稳定性的影响。结果表明,硫化NRL的最佳配方及工艺:促进剂ZBDC、硫黄、氧化锌用量分别为0.75,1.25,0.50份,硫化温度为70℃,硫化时间为2.5 h;随着促进剂ZBDC用量的增加,NRL硫化胶膜的交联密度逐渐增大,而300%定伸应力、500%定伸应力、700%定伸应力、拉伸强度均呈现先增大后减小的趋势;当促进剂ZBDC与ZDC并用时,硫化胶膜的300%定伸应力、500%定伸应力、700%定伸应力和交联密度都达到了最大值,但拉伸强度和撕裂强度比采用最优方案制得硫化胶膜小;随着促进剂ZBDC用量的增加,NRL硫化胶膜的耐老化性能先提高后又下降;无论ZDC与ZBDC并用还是单独使用,硫化胶膜的耐老化性能都较优;随着贮存时间的延长,无论是使用环保型促进剂ZBDC还是使用促进剂ZDC,NRL的硫化程度均增加,硫化NRL的黏度均逐渐增大,而机械稳定性先稍有提高后下降。

The curing formula and process condi- tions of natural rubber latex （NRL） were optimized by orthogonal experiment with zinc dibenzyl dithio- carbamate（ZBDC） , A-IO, TBzTD as accelerator, the effects of ZBDC and conventional accelerator ZDC on properties of vulcanized NRL films were compared, and effects of storage time on NRL curing degree and viscosity and mechanical stability of vul- canized NRL were investigated. The results showed that the best vulcanization formula and process con- ditions of NRL were 0. 75, 1.25, 0.50 phr of pro- moter ZBDC, sulfur, zinc oxide, 70 ℃ of curing temperature, 2.5 h of vulcanization time respective- ly. With increasing ZBDC amount, crosslinking density of vulcanized NRL film increased gradually, and modulus at 300% , modulus at 500% , modulus at 700% and tensile strength increased first and then decreased. And the modulus at 300% , modulus at 500%, modulus at 700% and crosslinking density reached the maximum with blending ZBDC and ZDC, but the tensile strength and tear strength was smaller than those of vulcanized NRL film with the optimum formula. With increasing ZBDC, aging re- sistance of vulcanized NRL film increased first and then decreased, whether blending ZDC and ZBDC or using ZDC alone, aging resistance of vulcanized NRL film was better. With the extension of storage time, whether using ZBDC or adding ZDC, curing degree of NRL increased gradually, viscosity of vul- canized NRL gradually increased, and the mechani- cal stability improved slightly first and then reduced.