No abstract

Experimental evidence is presented that during the conditions of aqueous heterophase polymerization radical generation and subsequent polymerization are induced by the interfacial energy. A comprehensive study of the emulsion polymerization of styrene at 25 °C with various types of emulsifiers and with different nonredox initiators such as potassium peroxodisulfate, 2,2′-azoisobutyronitrile, dibenzoyl peroxide, and poly(ethylene glycol)-azo-initiator reveals that the particular initiator-stabilizer combination has a strong influence on the achievable final conversion and the latex properties. The deceleration of the polymerization due to the low temperature allowed the recognition of basic differences in the behavior of monomer-and water-soluble initiators, especially at low conversions during the prenucleation period.

Soluble and processable conductive copolymers of silicone tegomers and pyrrole were developed. This was easily accomplished by the oxidative polymerization of pyrrole monomer by Ce(IV) salt in the presence of silicone tegomers with hydroxyl chain ends. The resulting copolymers were soluble in dimethylformamide. The products were characterized by Fourier transform infrared, 1 H-NMR, and four-point probe conductivity, and their surface properties were investigated with contact-angle measurements.

In this study, a small amount of vinylphosphonic acid was used to produce fire‐retardant copolymers and terpolymers from acrylonitrile and methyl acrylate. The structures of copolymer and terpolymers were elucidated by 1H‐NMR and phosphorous analysis. Thermal decomposition of vinylphosphonic acid‐containing copolymers and terpolymers started at lower temperatures than of poly(acrylonitrile‐co‐methyl acrylate). Methyl acrylate contributes to the thermal resistance of the terpolymers. Poly(acrylonitrile‐co‐methyl acrylate‐co‐vinylphosphonic acid) with a phosphorous content about 0.25% burned at a slower rate and emitted less smoke compared to poly(acrylonitrile‐co‐methyl acrylate). The burning tests showed that both copolymer and terpolymers containing vinylphosphonic acid behaved as a fire‐retardant polymer. The phosphonate and phosphonic acid groups in the copolymer and terpolymers accelerate the cyclization of nitrile groups and inhibit the fire in the gas phase. Nanofibers were successfully produced by the electrospinning method from the copolymers and terpolymers containing vinylphosphonic acid moiety.

Poly(acrylic acid) with molecular weight of 5000 was produced by using 2‐aminoethanethiol hydrochloride as chain transfer agent. Amine chain end groups of the resulting polyacrylic acid were transformed into nitrilodi(methylenephosphonic acid) by reacting formaldehyde‐phosphorous acid in the presence of hydrogen chloride. 1H NMR, 31P NMR and microanalysis were used for structural analysis.The modified polyacrylic acid had much better calcium carbonate scale inhibition effect than commercial poly(acrylic acid).