RIM聚氨酯弹性体预聚物的反应动力学研究

Reaction Kinetics of RIM Pu Prepolymer

在四个不同的温度下研究了四氢呋喃聚醚（ＰＴＭＧ），三羟甲基丙烷混合多元醇和甲苯二异氰酸酯（ＴＤＩ）的反应。无论是催化的还是非催化的反应，异氰酸根和羟基的反应均遵循二级反应力学，但４－位和２－位异氰酸根具有不同的反应活性。计算了４－位，２－位异氰酸根分别和羟基反应的速度常数ｋ１，ｋ２。活化参数Ｅａ１，Ｅａ２，△≠Ｓ１，△≠Ｓ２。随着反应体系的温度升高和催化剂ｍ－乙氧基三苯基铋（ｍ－ＯＥＴ－ＴＰＢ）的加入，ｋ１／ｋ２的比值减小。

The uncatalyzed and catalyzed bulk polymerizations of polytetrahydrofuran (PTMG) and trimethylolpropane(TMP) with toluene diisocyanate had been studied at four different tempertures. Discontinuity was obtained in the second order plots ofuncatalyzed and catalyzed reaction. The rate constants( k 1,k 2 ) and the activation parameters( Ea 1,Ea 2,Δ ≠S 1,Δ ≠S 2) for the isocyanate groups at the 4 and 2 positions were respectively calculated. The rate constant k 2 increased faster than k 1 and the ratio of k 1/k 2 decreased with added catalyst(m OET tribenzene bismuth) and increased temperture of the reaction system.