STUDIES ON CHAIN TRANSFER TO SUCCINIC ANH YDRIDE OF THF POLYMERIZATION

During the polymerization process of THF, active center can transfer t o succinic anhydride and produce polyether-ester block copolymer, If T DI is added into the system, the relative velocity of polymerization a nd chain transfer reaction can be controlled, It is found that when th e molar ratio of TDI/catalyst is it the polymerization can be accelera ted, while the transfer rate decreases during the latter period of the reaction, However, when this ratio is 5/1, the propagation rate chang es little, but the transfer rate increases, In the systems without TDI , with one time and five times moles of TDI as the mole of catalyst at 8 degrees C, the apparent propagation rate constants of THF, k(p) are 5.55 x 10(-3), 7.10 x 10(-3) and 8.10 x 10(-3) L/(mol . s), respectiv ely; the transfer rate constants k(tr) are 1.33 x 10(-3), 0.43 x 10(-3 ) and 5.55 x 10(-3) L/(mol . s), respectively.