کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5185836 1381089 2009 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Syntheses and characterization of novel biostable polyisobutylene based thermoplastic polyurethanes
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Syntheses and characterization of novel biostable polyisobutylene based thermoplastic polyurethanes
چکیده انگلیسی

The synthesis of polyisobutylene (PIB) based thermoplastic polyurethanes (TPU) with enhanced mechanical properties have been accomplished using poly(tetramethylene oxide) (PTMO) as a compatibilizer. PIB TPUs with Shore 60-100 A hardness were prepared by employing PIB diols (hydroxyallyl telechelic PIBs) for the soft segment and 4,4′-methylenebis(phenylisocyanate) (MDI) and 1,4-butanediol (BDO) for the hard segment. The TPUs exhibited number average molecular weight (Mn) in the range of 83,000-110,000 g/mol with polydispersity indices (PDIs) = 1.8-3.1. These TPUs, however, were inferior compared to commercial TPUs such as Pellethane™ (Dow Chemical Co.) as they exhibited low tensile strength (6-15 MPa) and/or ultimate elongation (30-400%). Processing of the harder compositions was also difficult and some could not be compression molded into flat sheets for testing. Differential Scanning Calorimetry (DSC) showed the presence of high melting (≥200 °C) crystalline hard segments suggesting longer - MDI-BDO - sequences than expected based on the stoichiometry. Easily processable TPUs with excellent mechanical properties (tensile strength up to 40 MPa, ultimate elongation up to 740%) were obtained by incorporating PTMO in the soft segment. Examination of PIB-PTMO TPUs with varying hard: soft compositions (20:80, 35:65 and 40:60 wt:wt) and Shore hardness (60 A, 80 A and 95 A) indicated that substituting 10-30 wt% of PIB diol with PTMO diol is sufficient to reach mechanical properties similar to Pellethanes.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 50, Issue 15, 17 July 2009, Pages 3448-3457
نویسندگان
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