CHAIN EXTENSION REACTION OF PA1010 BY 2,2'-BIS(2-OXAZOLINE)

摘要

The reaction behavior of 2,2'-bis(2-oxazoline) (BOZ) has been studied to evaluate its coupling effects as the chain extender for polyaimde1010 (PA1010). It has been observed that the torque of PA1010 melt increased dramatically with the increase of reaction time. The maximal torque of PA1010 melt also increased with increasing the content of BOZ. However, addition of excess amount of BOZ led to more blocking reaction, not coupling reaction, indicating that the PA1010 of not-so-much-increased molecular weight but much-decreased carboxyl concentration would be produced. The PA1010, with end carboxyl group concentration of 52.8 eq/10{sup}6g and melt torque of 0.7 Nm at 240°C with a rotor speed of 40rpm, was added 0.84wt% BOZ to carry out a chain extension reaction. The resultant PA1010 having end carboxyl concentration of 8.2 eq/10{sup}6g and melt torque of 3.3Nm was achieved, after an optimal reaction time. The effect of temperature on the chain extension reaction rate accords with the Arrhenius exponential formula. In addition to temperature, the shear rate also has some effects on the chain-extension rate, which indicated that the higher the shear rate, the higher the reaction rate.