Novel Polyurethane Gels: The Effect of Structure on Gelation |
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Authors: | Pralay Maiti Ganga Radhakrishnan Palanisamy Aruna Goutam Ghosh |
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Affiliation: | 1. School of Materials Science and Technology, Banaras Hindu University, Varanasi 221 005, India;2. Polymer Science Division, Central Leather Research Institute, Adyar, Chennai 600 020, India;3. UGC-DAE Consortium for Scientific Research, Bhabha Atomic Research Centre, Mumbai 400 085, India |
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Abstract: | Novel polyurethane gels have been reported in common solvent like dimethyl formamide (DMF). Polyurethanes have been synthesized from diisocyanates, diols and rigid chain extenders. We have illustrated the influence of chemical structure of the chain extenders on gelation rate, thermal property and morphology of the gels in DMF. Gelation rate increases significantly with the rigidity of the chain extender. Introduction of more rigid chain extender molecules in polyurethane prepolymer enhanced the thermal stability of the pure polymer. On the contrary, the solvent retention power of the gels gradually decreases with increasing rigidity of chain extender presumably because of the poor dispersion/greater aggregation of the hard segments in the soft segment matrix. Morphology and formation of gelation have been discussed. |
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Keywords: | chain extender gelation morphology polyurethane thermal properties |
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