制备工艺对NR性能的影响

Effect of Preparation Processes on Properties of NR

采用新鲜天然胶乳分别制备乙酸凝固NR(NR-1)、微生物凝固NR(NR-2)、乙醇胺混合微生物凝固NR(NR-3)和蛋白酶混合自然凝固NR(NR-4),研究制备工艺对NR性能的影响。结果表明:NR-1和NR-2生胶的耐热老化性能和热稳定性好于NR-3和NR-4生胶;NR-4胶料的MH最大,t90最短,NR-3胶料的MH较小,t90最长;NR-4硫化胶的定伸应力和拉伸强度较大,拉断伸长率较小,NR-1硫化胶的定伸应力和拉伸强度较小;NR-4生胶、混炼胶和硫化胶的弹性转矩(S′)和剪切储能模量(G′)最大,损耗因子(tanδ)最小,NR-1生胶、混炼胶和硫化胶的S′和G′最小,tanδ值最大。

Four kinds of NRs were obtained by coagulating the fresh NR latex（NRL） with dif-ferent processes：NRL coagulated by acetic acid（NR-1）,NRL coagulated by microorganism（NR-2）,ethanolamine-blended NRL coagulated by microorganism（NR-3）,and protease-blended NRL coagulated naturally（NR-4）.The effect of preparation processes on the properties of NR was investigated.The results showed that,the raw NR-1 and NR-2 possessed better thermal aging property and thermal stability than the raw NR-3 and NR-4.The MH of NR-4 compound was the highest,and its t90 was the shortest.The MH of NR-3 compound was lower,and its t90 was the longest.The NR-4 vulcanizate possessed higher modulus and tensile strength,lower elongation at break.The NR-1 vulcanizate possessed lower modulus and tensile strength.The raw rubber,compound and vulcanizate of NR-4 exhibited the highest elastic torques（S′） and shear storage modulus（G′） and the lowest loss factors,whereas the lowest S′ and G′ and the highest loss factors were observed from those of NR-1.