Ammonium salt catalyzed copolymerization of 2‐hydroxy‐4‐(2,3‐epoxypropoxy)benzophenone with phthalic anhydride

Abstract

Ammonium salt catalyzed copolymerization of 2-hydroxy-4-(2,3-epoxypropoxy)benzophenone with phthalic anhydride was studied. The conversion curves could be linearized by the first order equation and the experimental rate constants kup for the initiation by various ammonium salts were determined. The rate of copolymerization was found to depend on the size of the cation but not on the type of anion. kexp is a function of the first power initiator concentration but is independent of epoxide and anhydride concentration. The activation energy for the cetyltrimethylammonium bromide (CAB) initiated copolymerization in nitrobenzene was determined to be 733 kJ/mol. The kinetic scheme of copolymerization, which agrees welt with the experimental results, was solved. The rate constant of the copolymerization of 2-hydroxy4(2,3-epoxypropoxy)benzophenone with phthalic anhydride catalyzed by CAB in nitrobenzene was found to be 2,76. lo-' 1. mol-I * s-'. The ratio of rate constants for both propagation steps, i.e. reaction of carboxylate anion with epoxide (k3) and reaction of alkoxide anion with anhydride (k'), was determined to be k3/k2 = 0,2 f 0,l.

Degradation and Stabilization of Polymers

“…In addition, they may phaseseparate on the polymer surface. The physical chemistry of polymer additives has been extensively discussed (Billingham and Calvert, 1980;Billingham, 1990;Moisan, 1985;Luston, 1980).…”

Kinetics of the Condensation Reaction of Epoxide with Phenol: Linear Chain Growth versus Branching

“…This condition is included to allow for the possibility of both primary and secondary alcohols forming upon opening of the oxirane ring. From these expressions, the rate of change of each component can be expressed in general terms as (5) where = 1 or 2, allowing for a catalytic effect of the Bisphenol A on the reaction rates. When eq 5 is divided by eq 4 and integrated with the boundary condition that initially P = 1.0 and 0\ = 0.0, we obtain Oj ^£j[l -P(ill,-1)] P £: -1 (6) where = k2¡¡2/kith• Equation 3 can be rearranged to df 'M1 6,(tl«-l) J Similarly, eq 3 and 4 can be combined to yield (£o-a = (r0-P)…”

Effect of crosslinking density on the diffusion of antioxidant in XLPE matrices

“…Powdered LDPE was dry blended with dicumyl peroxide in concentrations of 1,2,4,6,8 and 10 percent. The dry blends were homogenized on a two-roll mill at 115°C.…”

“…A comprehensive review on physical loss of antioxidants from polymers was given by Luston (1). Factors including distribution of stabilizers in polymers, mutual compatibility, volatility, extractability, and diffusion rates of the antioxidants were discussed.…”