Silicon-Containing Soybean-Oil-Based Copolymers. Synthesis and Properties

• Published in: Biomacromolecules 2009-09, Vol.10 (9), p.2678-2685
• Main Authors: Sacristán, Marta, Ronda, Joan C, Galià, Marina, Cádiz, Virginia
• Format: Article
• Language: English
• Subjects: Applied sciences; Copolymerization; Exact sciences and technology; Flame Retardants - chemical synthesis; Organic polymers; Physicochemistry of polymers; Polymers - chemical synthesis; Preparation, kinetics, thermodynamics, mechanism and catalysts; Silicon - chemistry; Soybean Oil - chemistry; Transition Temperature
• ISSN: 1525-7797; 1526-4602
• DOI: 10.1021/bm9006166

New silicon-containing soybean-oil-based copolymers were prepared from soybean oil, styrene, divinylbenzene, and p-trimethylsilylstyrene by cationic polymerization using boron trifluoride etherate as initiator. Soxhlet extraction and NMR spectroscopy indicate that the copolymers consist of a cross-linked network plasticized with varying amounts of oligomers and unreacted oil. This soluble fraction increases when the SiST content in the feed increases, according to a lower reactivity of this monomer. The thermal, dynamomechanical, and flame-retardant properties of these materials were examined. Thermosets with glass transition temperatures ranging from 50 to 62 °C, which are thermally stable below 350 °C, and with LOI values from 22.6 to 29.7 were obtained. Their properties suggest that these materials may prove to be useful alternatives for current non-renewable-based thermosets and that the flame-retardant properties of vegetable-oil-based thermosets can be improved by adding covalently bonded silicon to the polymer.