Polymerization of N-acryloyl pyrrolidone

Abstract

N-acryloyl pyrrolidone was synthesized by the reaction of pyrrolidone with acryloyl chloride. First, the polymerization of N-acryloyl pyrrolidone and copolymerization of N-acryloyl pyrrolidone with styrene were carried out at $60^\circ C$, using 2,2``-azobisisobutyronitrile as an initiator. Kinetic studies showed that the rate of polymerization could be expressed by : $$R_p=\mbox{K(AIBN)}^{\frac{1}{2}}\mbox{(NAP)}$$ The reactivity of N-acryloyl pyrrolidone was found to be larger than that of N-methacryloyl pyrrolidone. The overall activation energy was calculated to be 24.3 kcal $mol^{-1}$. The following monomer reactivity ratio and Q,e value were obtained : NAP(Ml)-St(M2) ; r1=1.5, r2=0.35, Q1=0.42, and el=1.6. Second, ring-opening polymerization of pyrrolidone using N-acryloyl pyrrolidone as an activator was carried out. Third, graft copolymers were synthesized by reacting pyrrolidone, in the presence of catalytic amount of its potassium salt, with poly(acryloyl pyrrolidone-styrene). The pair of cobaltous chloride with N,N-dimethylaniline(DMA) has been investigated as an initiator for the polymerization of acrylamide in aqueous media 30, 40, and $50^\circ C$ in a nitrogen atmosphere. The rate of polymerization was found to be proportional to the $\mbox{(monomer)}^P1.0}$ over the range of $0.5-2.0\times10^{-2}M$. The reaction order related to the cobaltous chloride concentration was 0.53, which indicated a bimolecular mechanism for the termination reaction in the range of $0.2-2.0\times10^{-4}M$. The rate of polymerization and the maximum conversion falled as the temperature rised above $40^\circ C$. The apparent activation energy was 9.38 kcal/mol in the temperature range of 30-$50^\circ C$. Methanol decreased the rate of polymerization and polymerization was completely stopped when benzoquinone was added during an induction period. The reaction mechanism was proposed on the basis of the experimental data.