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Polyurethane networks from different soy‐based polyols by the ring opening of epoxidized soybean oil with methanol, glycol, and 1,2‐propanediol
Author(s) -
Wang ChengShuang,
Yang LiTing,
Ni BaoLian,
Shi Guang
Publication year - 2009
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.30493
Subject(s) - polyol , polyurethane , soybean oil , materials science , epoxidized soybean oil , glass transition , toluene diisocyanate , differential scanning calorimetry , thermal stability , thermogravimetry , methanol , ultimate tensile strength , hydroxyl value , polymer chemistry , organic chemistry , polymer , chemical engineering , composite material , chemistry , raw material , physics , food science , engineering , thermodynamics
Abstract A series of polyols with a range of hydroxyl (OH) numbers based on soybean oil and epoxidized soybean oil were prepared by oxirane ring opening with methanol, glycol, and 1,2‐propanediol. The polyols, with average functionalities varying from 2.6 to 4.9, were characterized. Novel cast polyurethane resins were synthesized from these polyols and 2,4‐toluene diisocyanate. The sol fraction of the network decreased as the OH number of the polyol from which it was synthesized increased. None of the samples were completely soluble. The crosslinking density of the polyurethanes correlated directly with the functionality of the polyols. The thermal and mechanical properties of the cast resins were characterized with differential scanning calorimetry and thermogravimetry. The glass‐transition temperature increased with the OH number increasing, and the thermal stability of the resins was slightly decreased with the OH number increasing. The tensile strength at break increased with the OH number increasing. Polyurethanes prepared from polyols with OH numbers higher than 170 mg of KOH/g were glassy, whereas those with OH numbers below that value were rubbery. Glassy polyurethanes displayed decent mechanical strength, whereas rubbery samples showed relatively poor elastic properties and were characterized by lower strength. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009