Determination of solubility parameters of cross-linked macromonomeric initiators based on polypropylene glycol
A Alli, B Hazer, BM Baysal
article (Uluslararası, Hakemli) | Yazar(lar): A Alli, B Hazer, BM Baysal | Yıl: 2006 | Dergi/Kurum: EUROPEAN POLYMER JOURNAL | İndeks: WOS.SCI | DOI: 10.1016/j.eurpolymj.2006.07.012 | Anahtar Kelimeler: macroinimer (macromonomeric initiator), cross-linked polypropyleneglycol (cross-linked PPG), self-condensing radical
A new type macromonomeric azo initiators also named macroinimers, MIMs, based on polypropylene glycol, PPG, with molecular weight 400 and 2000, were synthesized. Self-condensing radical polymerization of the macroinimers gave cross-linked polypropylene glycols. The solubility parameters of the cross-linked polymers determined using swelling experiments in a series of solvents have been reported. Cross-linked PPG-400 and cross-linked PPG-2000 indicated the same solubility parameter value. But their swelling ratios were different because of the differences of the chain lengths in between of the cross-points (Me) of the gels. Therefore, while the largest swelling ratio exhibited by a cross-linked PPG-2000 in tetrahydrofurane was being 19.48, this ratio was 6.84 for the cross-linked PPG-400 in the same solvent. The solubility parameters and constant alpha for these cross-linked polymers were obtained as delta(cross-linked) (PPG-400) = 9.56 (cal cm(-3))(1/2), alpha = 0.123 cm(3) cal(-1) and delta(cross-linked PPG-2000) = 8.95 (cal cm(-3))(1/2), alpha = 0.107 cm(3) cal(-1) by using the least squares regression method. (c) 2006 Published by Elsevier Ltd.