碳酸二甲酯与1,5-戊二醇制备聚(碳酸1,5-戊二醇酯)二醇预聚反应的热力学计算与分析  

THERMODYNAMICS OF PREPOLYMERIZATION BETWEEN DIMETHYL CARBONATE AND 1,5-PENTANEDIOL TO POLY(1,5-PENTANEDIOL)CARBONATE DIOL

作　　者：王丽苹[1] 赵粒成 兰开顺 解都 

机构地区：[1]曲靖师范学院化学与环境科学学院,云南曲靖655011

出　　处：《精细石油化工》2017年第1期64-69,共6页Speciality Petrochemicals

基　　金：云南省应用基础研究计划项目(2013FZ108)

摘　　要：利用Benson基团贡献法和Joback基团贡献法对以DMC与1,5-戊二醇为原料制备聚(碳酸1,5-戊二醇酯)二醇预聚反应的焓变(△_rH~θ)、熵变(△_rS~θ)、反应吉布斯自由能变(△_rG~θ)及平衡常数(K_p)进行了计算。结果表明,在373~473 K,主反应的焓变均为负值,为放热反应,升高温度不利于反应的进行。甲基羟戊基碳酸酯(MHPC)与1,5-戊二醇反应的平衡常数明显比MHPC歧化反应的大,这表明MHPC上羟基的反应活性低于1,5-戊二醇分子上的羟基。因此,DMC与1,5-戊二醇预聚反应的可能机理是1,5-戊二醇分子上的羟基氧进攻DMC分子上的羰基碳反应生成MHPC,MHPC进一步与1,5-戊二醇反应生成预聚体二羟戊基碳酸酯。Group contribution methods were used to analyze the enthalpy changes,entropy changes,Gibbs free changes and equilibrium constants in the prepolymerization between dimethyl carbonate and 1,5-pentanediol to poly（1,5-pentanediol）carbonate diol.The results show that main reactions are exothermic and higher temperature is unfavorable for the reactions.The equilibrium constant of reaction between methyl hdroxypentyl carbonates（MHPC）and 1,5-pentanediol is higher than that of dismutase reaction between MHPCs,which exhibits that the reactivity of hydroxyl radical in MHPC is lower than that of hydroxyl group in 1,5-pentanediol.So the possible mechanism is that oxygen atom of hydroxyl group in 1,5-pentanediol attack carbon atom of carbonyl group in dimethyl carbonate to form methyl hdroxybutyl carbonate（MHPC）,and MHPC react with 1,5-pentanediol to form bishdroxypentyl carbonate（BHPC）.

关 键 词：碳酸二甲酯 1 5-戊二醇 甲醇 基团贡献法 

分 类 号：TQ323.41[化学工程—合成树脂塑料工业]