کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9694148 | 1459640 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Melting and thermal history of poly(hydroxybutyrate-co-hydroxyvalerate) using step-scan DSC
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
جریان سیال و فرایندهای انتقال
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چکیده انگلیسی
Melting behaviour and crystal morphology of poly(3-hydroxybutyrate) (PHB) and its copolymer of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with various hydroxyvalerate (HV) contents [5Â wt.% (PHB5HV), 8Â wt.% (PHB8HV) and 12Â wt.% (PHB12HV)] have been investigated by conventional DSC, step-scan differential scanning calorimetry (SDSC) and hot-stage polarised optical microscopy (HSPOM). Crystallisation behaviour of PHB and its copolymers were investigated by SDSC. Thermal properties were investigated after different crystallisation treatments, fast, medium and slow cooling. Multiple melting peak behaviour was observed for all polymers. SDSC data revealed that PHB and its copolymers undergo melting-recrystallisation-remelting during heating, as evidenced by exothermic peaks in the IsoK baseline (non-reversing signal). An increase in degree of crystallinity due to significant melt-recrystallisation was observed for slow-cooled copolymers. PHB5HV showed different crystal morphologies for various crystallisation conditions. SDSC proved a convenient and precise method for measurement of the apparent thermodynamic specific heat (reversing signal) HSPOM results showed that the crystallisation rates and sizes of spherulites were significantly reduced as crystallisation rate increased.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Thermochimica Acta - Volume 430, Issues 1â2, June 2005, Pages 183-190
Journal: Thermochimica Acta - Volume 430, Issues 1â2, June 2005, Pages 183-190
نویسندگان
L.M.W.K. Gunaratne, R.A. Shanks,