The Research On Copolymerization Of N-Phenylmaleimide And Styrene

N-substituted maleimides can polymerize with vinyl monomers duing to their unique plane five-spot chain strctures to gain the functional polymers. The heat-resistant capabilities of polymers obtained with N-substituted maleimides are markedly improved but its other capabilities steadly. So N-substituted maleimides are usually used as heat-resistors. In this aticle, several methods of synthesis and the developing trends of the methods of N-substituted maleimides were summarized.At preasent much investigation of copolymerization of N-phenylmaleimde and styrene has been taken. Many investigators have proved that there are the charge-transfer complexes in the polymerization and received alternating copolymers. Then, the copolymerization of styene and N-phenylmaleimide investigated with multifunctional initiators.The alternative copolymers of N-phenylmaleimide and styrene (P-NPMI-St)(mol ratio: 1:1) with end functional group were synthesized successfully in tetrahydrofuran, and the polydispersities are Mw/Mn=1.8. The result was proved by the measure of infrared spectroscopy (IR), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). Gel permeation chromatography analysis showed that the molecular weight were above 105 and the molecular weight decreases was narrow polydispersities.The thermodynamic properties of P-NPMI-St were researched by different scanning calorimrtry (DSC) and thermogravimetry (TG). It showed that the polymers were well heat-resisitant and the T10% and T50%of P-NPMI-St were 393℃and 426℃. Then, the polymers are decompounded completely without the pollution to environment.The kinetics of the polymerization was carried out, as well as the mechanism of every step of radical reaction and the style of chain-ending were analysted. The influence of the time, the concentration of initiator, the temperature to the molecular weightand polymerization rate was inspected. The reaction energy were determined. And the result indicated that the polymerization rate increases with increasing the time, the concentration of initiator, as well as the reaction temperature. But the molecular weight decreases with the concentration of initiator and the reaction temperation. The connection of time with coversion and the value of Ln[M]₀/[M]_t was researched in low coversion rate. And the results showed that with the time increased, the conversion and the value of Ln[M] t /[M] 0 increased linearly. All these results proved that there was the free radical during the processing of the polymerization.. The equation of the polymerization rate was Rp=K[ACVA]^0.59[M] with the apparent activation energy of 53.80kJ/mol for N-phenylmaleimde and styrene copolymerization.