【作者】 孙玉海；

【导师】 张培新； 刘剑洪；

【作者基本信息】 广西大学 ， 应用化学， 2004， 硕士

【摘要】 本文利用裂解气相色谱-质谱(Py-GC-MS)联用技术研究了天然橡胶、异戊二烯橡胶和顺丁二烯橡胶的裂解产物和裂解温度的关系。并通过对裂解产物的分析研究了天然橡胶、异戊二烯橡胶和顺丁二烯橡胶的裂解机理。 利用热重分析(TG)和微商热重分析(DTG)研究了天然橡胶、异戊二烯橡胶和顺丁二烯橡胶的热解动力学。利用不同升温速率下相同失重量下的不同失重速率和温度的关系求解了裂解反应活化能。同时利用示差扫描量热法(DSC)研究了天然橡胶、异戊二烯橡胶和顺丁二烯橡胶裂解时的热能变化。也利用不同升温速率下最大放热峰温度值求解了裂解表观活化能。 结果表明：裂解温度对裂解产物影响较大，随着裂解温度的增加，裂解产物中单体和二聚体增加。当裂解温度较高的时候还会出现少量的无规断裂碎片。天然橡胶的裂解过程和异戊二烯橡胶的裂解过程基本相同，生成了大量的异戊二烯单体和1，4-二甲基-4-乙烯基环己烯。顺丁二烯橡胶裂解生成了大量的顺丁二烯单体和乙烯基环己烯。随着升温速率的提高TG曲线起始温度和DTG曲线峰值温度都逐渐提高。利用TG—DTG数据计算的裂解表观活化能表明，天然橡胶和异戊二烯橡胶的裂解表观活化能基本相同，天然橡胶的裂解表观活化能E=240.skJ/m。卜1;异戊二烯橡胶的裂解表观活化能E二248.0kJ/mo卜1。E，二2 1 9.5kJ/mo}一1顺丁二烯橡胶第一步裂解的表观活化能第二步裂解的表观活化能已二229.2 kJ/mol一1。DSC曲线的峰值温度也随升温速率的增加而增加。利用OSc数据计算的裂解表观活化能与利用TG一DTG数据计算的裂解表观活化能相比误差较大。更多还原

【Abstract】 The relationship between pyrolysis production and temperature of nature rubber isoprene rubber and butadiene rubber was investigated by Pyrolysis Gas-Chromatography-Mass Spectrometry(Py-GC-MS) . The pyrolysis mechanism of nature rubber, isoprene rubber and butadiene rubber was analysis by pyrolysis production.The pyrolysis dynamics of nature rubber , isoprene rubber and butadiene rubber was investigated by thermogravimetry analysis(TG)and differential thermogravimetry analysis(DTG). Use the relationship between the different weight-loss rate at the same weight-loss under different heating rate and time to calculate the activation energy. The heat energy of pyrolysis was studied by differential scanning calorimetry (DSC) at same time. The activation energy was also calculated by the temperature of peak on DSC curve at different heating rates.The results turned out that pyrolitic temperature has great affection on the out come of pyrolysis. The monomer and di- monomer in the out come increase with the adding of heating rate. There are few random rupture fragments in the production at the higher temperature. Thepyrolitic mechanism of nature rubber is similar with it of isoprene rubber. There are mainly isoprene monomer and 1,4-dimethyl-4-ethenyl cyclohexene in the out come of pyrolysis of nature rubber and isoprene rubber. There are mainly butadiene and 4-ethenyl cyclohexene in the out come of pyrolysis of butadiene rubber. The temperatures of peak in TG curves and DTG curves all increase with the adding of heating rate. The pyrolitic activation energies of nature rubber and isoprene calculated by TG-DTG date are similar. The activation energy of nature rubber pyrolysis is E=240.8 kJ/mol-1, the activation energy of isoprene rubber pyrolysis is E=248.0 kJ/mol-1. The activation energies of two step butadiene rubber pyrolysis is El=219.5 kJ/mol-1 E2=229.2 kJ/mol-1 respectively. The temperatures of peak on the DSC curves increase with the increase of heating rate. The activation energy calculated by DSC date is bigger error than it calculated by TG-DTG date.更多还原