超临界二氧化碳中再生硫化天然橡胶的影响因素及脱硫效果  

Influence factors and devulcanization effect of reclaiming vulcanized natural rubber in supercritical carbon dioxide

作　　者：葛佑勇[1] 李晓林[1] 辛晓[1] 伍社毛[1] 张立群[1] 

机构地区：[1]北京化工大学北京市新型高分子材料制备与成型加工重点实验室,北京100029

出　　处：《合成橡胶工业》2010年第5期370-373,共4页China Synthetic Rubber Industry

摘　　要：以二苯基二硫化物(DD)为脱硫剂,在超临界CO2作用下对硫化天然橡胶(NR)进行了脱硫再生,考察了CO2密度、反应温度和压力以及反应时间等对脱硫作用的影响,并对脱硫降解产物进行了相对分子质量测定和核磁共振表征。结果表明,采用超临界CO2流体为溶剂可以实现对硫化NR的脱硫降解,脱硫降解条件为CO2的密度不小于0.4722g/cm3、反应温度不低于160℃、反应时间不少于90min;溶胶率随降解温度的提高和时间的延长而增大;在降解过程中除了S—S、S—C断裂外还发生了部分主链断裂,降解后橡胶相对分子质量下降;脱硫剂DD能有效打开硫交联键,脱硫降解后再生胶分子中引入了少量的苯环结构。The vulcanized natural rubber （NR） was devulcanized in supercritical CO2 fluid by using diphenyl disulfide （DD） as a devulcanizing reagent. The effects of CO2 density, temperature, pressure and reaction time on the devulcanization were dis- cussed. The degradation products from the devulea- nization were characterized by gel permeation chro- matography and nuclear magnetic resonance. The re- sults showed that the vulcanized NR was devulca- nized when supercritical CO/ used as solvent under the conditions in which the density of the supercriti- cal CO2 fluid was over 0. 472 2 g/cm3 , the tempera-ture was above 160℃ ,and the reaction time should be lasted to more than 90 min. The sol ratio in- creased with the increase of reaction temperature and time. In devulcanization, besides S--S and S--C, a part of main chain was cloven, leading to the relative molecular mass of the reclaiming rubber decreased. The devulcanizing reagent DD could open crosslinked bond effectively, and there was a little benzene ring structure introduced in the reclaiming rubber.

关 键 词：超临界二氧化碳 天然橡胶 硫化胶 二苯基二硫化物 脱硫 再生 

分 类 号：TQ330.13[化学工程—橡胶工业]