【摘 要】
:
Tolylene-2,4-diisocyanate(2,4-TDI)1 reacts with methanol through two simultaneous paths in the polyurethane reaction,which involve two different intermediates-t
【机 构】
:
Key Laboratory of Fine Chemicals(Shandong Province),Science and Technology Office,School of Chemical
【基金项目】
:
the National Natural Science Foundation of Shandong Province;国家自然科学基金
论文部分内容阅读
Tolylene-2,4-diisocyanate(2,4-TDI)1 reacts with methanol through two simultaneous paths in the polyurethane reaction,which involve two different intermediates-tolylene-4-caxbamatic-2-isocyanate 2 and tolylene-2-carbamatic-4-isocyanate 3,and the final product is tolylene-2,4-dicarbamate 4.The-CH3 chemical shifts in benzene ring in compounds 1,2,3 and 4 can be easily tested and well distinguished,through which those four compounds are quantified and their kinetics are investigated.It shows that four rate constants for the tolylene-2,4-diisocyanate-methanol reaction in CCl4 at 50℃ are k1 =9.6×10-2h-2mol-2min-1k2=1.4×10-2h-2mol-2min-l,k3=4.0×10-3h-2mol-2min-1,k4=1.4×10-3h-2mol-2min-1.(k1 is the reaction rate constant from compounds 1 to 2; k2 is the reaction rate constant from compounds 1 to 3; k3 is the reaction rate constant from compounds 3 to 4; k4 is the reaction rate constant from compounds 2 to 4).
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