Radical copolymerizations of β‐propiolactone with acrylonitrile and with styrene

Abstract

Radical copolymerizations of β‐propiolactone (denoted 2) with acrylonitrile (denoted 1) and with styrene (also denoted 1) and the structures of the resulting copolymers were studied. The bulk copolymerization with acrylonitrile by α,α′‐azobisisobutyronitrile at 50°C gave polyesteracrylonitriles of high enough molecular weight to form tough and transparent films, with the monomer reactivity ratios, r1 = 0.84, r2 = 0.00, and the structure of the copolymers was magnified image Radical copolymerization with the same initiator in N,N‐dimethylformamide gave polyesteracrylonitriles of the same structure as that of the bulk polymer, blended with β‐propiolactone homopolymer which was due to the competing anionic homopolymerization of β‐propiolactone. The reactivity ratios on the bulk copolymerization with styrene were r1 = 6.2 and r2 = 0.0 with benzoyl peroxide at 80°C, and r1 ≅ 32, r2 = 0 with α,α′‐azobisisobutyronitrile at 50°C. Polyesterstyrenes of intrinsic viscosity up to 0.83 were obtained.

Synthesis and properties of block poly(styrene amides) and poly(styrene esters)

“…w,d-Diaminopolystyrene. A 70-g portion of powdery w,w'-dichloropolystyrene was placed in a 700-ml steel bomb, which was sealed after intro- (1)(2)(3)(4) refer to the corresponding w, w'-dichloropolystyrenes as start-Chlorine content and intrinsic viscosity ing material prepared as given in Table I. were measured by the same methods as in Table I. (1)(2)(3)(4) refer t o the corresponding w, w'-dichloropolystyrene as starting Chlorine content was measured by the same material prepared as given in Table I.…”

“…method as in Table I. (1)(2)(3)(4) refer to the corresponding number of the starting material in Table I. duction of excess liquid ammonia.…”

“…Copolymers of various structures were studied from two points of view: (1) preparation and characterization of copolymers of a pair of definite monomers but with different configurations such as b r a n~h e d ,~.~ endblock,a10 block,11-16 graft,17-21 and random1.6J2-14~22~23 copolymers; (2) syntheses and characterizations of copolymers having comonomer units each of which polymerizes in itself by a different polymerization mechanism or by the same mechanism, such as additi~n-addition,l,~.~~-~~.~~ ring-opening-ring-opening? condensation-condensation,5.22 additi~n-ring-opening,~O,~~-~~ addition-condensation,l5 condensation-ring-opening,ll polyaddition-c~ndensation,~,~,~J~ and polyaddition-condensation-ring-openings copolymerizations.…”

A Rare Example of the Formation of Polystyrene‐Grafted Aliphatic Polyester in One‐Pot by Radical Polymerization

“…During copolymerization with vinyl monomers, such as acrylonitrile and styrene (St), b-PL showed a large difference in reactivity, with the formation of blocky statistical copolymers, possessing long blocks of the vinyl polymer separated by one ester unit from b-PL. [8] In an attempt to utilize free-radical copolymerization reactions of b-PL with vinyl monomers (e.g. styrene) for the formation of degradable functional polymers, we observed the formation of an unusual polymer architecture (graft copolymers (PSt-g-b-PL)) in one step, depending upon the feed composition.…”

“…[6] The first radical polymerization of b-PL was reported by Ohse et al, [7] without structural and mechanistic clarifications. Katayama et al [8] provided the mechanism for RROP of b-PL, showing the formation of ester (-C(O)OCH 2 CH 2 -) repeat units. During copolymerization with vinyl monomers, such as acrylonitrile and styrene (St), b-PL showed a large difference in reactivity, with the formation of blocky statistical copolymers, possessing long blocks of the vinyl polymer separated by one ester unit from b-PL.…”