It is highly desirable to produce elastomeric foams directly from liquid components. Flexible urethanes, the only technologically important elastomeric foams that are commercially available, are enjoying rapid growth. An essential feature of a successful foam system is the ability to attain the appropriate balance between gas generation and cure reaction. We report here a completely new system which allows syrups, consisting of polymer dissolved in free-radically polymerizable monomers, to be foamed directly using certain azo compounds. Our preliminary results show that a number of different azo compounds may be utilized to produce elastomeric foams over a wide density range. The variables which can effectively control the foaming and curing reaction are discussed, but there has been no attempt to optimize the physical properties of the flexible foams. Physical property evaluations will be the subject of future publications. We illustrate the versatility of the system and believe that properties may be easily tailored to end-use needs by appropriate selection of formulation components.

Bis(beta‐chloroethyl) vinylphosphonate and vinyl chloride were copolymerized free‐radically in water suspension and in toluene solution at 55°C. From compositional analysis of the low‐conversion copolymers, the reactivity ratios of bis(beta‐chloroethyl) vinylphosphonate (r1) and vinyl chloride (r2) were found to be 0.37 ± 0.1 and 0.26 ± 0.05, respectively, indicating that the two monomers have a marked tendency to alternate. From the Q and e values of vinyl chloride, the corresponding Q.e values for the vinylphosphonate are calculated to be 0.23 and 1.73, respectively. Interestingly, the rate of copolymerization is greater than that of homopolymerization, and is also greater when water is present. These copolymerization characteristics are deemed favorable in industrial productions. The copolymers have lower viscosities and glass temperatures than poly (vinyl chloride). From patent literature, the copolymers also show useful flame retardant properties.

SynopsisDi(t-butylperoxy) fumarate was copolymerized with styrene, butadiene, acrylonitrile, methyl methacrylate, vinyl chloride and vinyl acetate to give copolymers containing pendant peroxyester functions. Another peroxide was generally used for initiating polymerization: however, experiments were carried out with di(t-butylperoxy) fumarate as both initiating species and comonomer. The active oxygen contents and intrinsic viscosities were determined for these copolymers. A copolymer of styrene and di(t-butylperoxy) fumarate synthesized from monomers in equal weight ratio had an active oxygen content of 5.3% and a peroxide halflife of 7.7 hr. at 85OC. in benzene. This peroxide was used as a catalyst for the curing of polyester resins and as an initiator for styrene bulk polymerization. The monomer reactivity ratios for the monomer pair styrene-di(t-butylperoxy) fumarate were determined. Graft copolymers were made by grafting methyl methacrylate on a styrene-di(t-butylperoxy) fumarate copolymer and also by grafting styrene on a vinyl acetate-di(t-butylperoxy) fumarate copolymer. These graft copolymers were used to enhance the stability of homopolymer-solvent mixtures. A novel ABS type of resin was synthesized by grafting styrene and acrylonitrile on the copolymer system butadiene-di(t-butylperoxy) fumarate. Another novel resin was synthesized by grafting butadiene on the terpolymer system styrene-acrylonitrile-di(t-butylperoxy) fumarate. A homopolymer of di(t-butylperoxy) fumarate was also prepared and used as a catalyst for the curing of polyester resins.

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