稀土掺杂高耐磨炭黑填充型粉末NR研究 (Ⅱ)交联密度

Study on(HAF carbon black-rare earth)-filled powdered NR (Ⅱ) Crosslink density

以溶胀指数SI(Swelling Index)为指示参数,研究了稀土用量及炭黑用量对稀土掺杂高耐磨炭黑填充型粉末天然橡胶[P(NR/N330-Ln)]硫化胶的交联密度的影响,并与无稀土粉末胶[P(NR/N330)]及无稀土块胶(MNR/N330)的硫化胶做对比。结果表明,随着稀土用量的增加,硫化胶的溶胀指数(SI)的变化出现4个阶段,这是N330粒子上的稀土对硫化胶表观交联密度的贡献有两种相反的作用,即阻碍生成炭黑凝胶从而降低表观交联密度的作用,增大N330-Ln的表面效应,提高稀土结合橡胶的生成量从而提高表观交联密度的作用的综合结果。随着炭黑用量的增加,P(NR/N330)和P(NR/N330-Sm)硫化胶的交联密度高于MNR/N330硫化胶,各种硫化胶在炭黑填充量为100份时的交联密度几乎相同。

Measured by SI（Swelling Index）, the effects of the content of rare earth and HAF on the crosslink density of rare earth-doped HAF-filled powdered nature rubber [ P （NR/N330-Ln） ] vulcanizate were investigated, whereas HAF-filled powdered nature rubber[ P（NR/N330） ] and HAF-filled bale nature rubber （MNR/N330） were used as comparisons. The results showed that the curves of SI versus Ln exhibited four stages, which was the co-effect of two opposite apparent crosslink density effects contributed by rare earth on N330 particles. One of the effects is the blocking effect of rare earth,which decrease apparent crosslink density by blocking the formation of carbon gel, the other effect is surface effect of rare earth, which could increase apparent crosslink density by increasing the content of Ln-NR. With the increase of the content of carbon black, the crosslink density of P （NR/N330） and P （NR/N330-Sm） vulcanizates was higher than that of MNR/N330, all vulcanizates＇ s crosslink density were same when HAF content was equal to 100 phr.