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Abstract  

High temperature pyrolysis studies of poly(phenylene vinylene)s PPVs with lateral substituents poly(ε-caprolactone) (PPV–PCL) or poly(ε-caprolactone) and alternating Br (PPV–PCL–Br) or polystyrene (PPV–PSt) clearly showed that thermal stability of both the substituent and PPV were affected by the thermal stability of the other. In all the polymers under investigation, decomposition started by the degradation of the substituent. The thermal stability of the PPV backbone increased in the order PPV–PCL–Br < PPV–PCL < PPV–PSt. When the thermal stability of the substituent was significantly lower than that of the PPV backbone, as in the case of PPV–PCL and PPV–PCL–Br, then the radicals generated at early stages of pyrolysis coupled before the temperature reached to the values necessary for complete decomposition. This inturn yielded a thermally more stable crosslinked structure. The increase in thermal stability was greater upon coupling of the radicals generated on the PPV backbone.

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Abstract  

The curing of the neat unsaturated polyester resin (UP) with benzoyl peroxide (initiator) as well as the curing of UP modified with two poly(ε-caprolactone) PCL samples (PCL2 and PCL50) of different molecular masses (M n=2⋅103 and M n=5⋅104, respectively), were investigated by non-isothermal differential scanning calorimetry (DSC), at different heating rates. The activation energy was determined from the variation of the peak exotherm temperature, T peak, upon heating rate. Besides, the degree of conversion (α) was obtained from isothermal DSC measurements at 80°C at different curing times for neat UP, UP+ PCL2 and UP+PCL50. Kinetic parameters were deduced assuming the n th order reaction kinetic model for neat UP, UP+PCL2 and UP+PCL50 systems.

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Abstract  

Poly(2-hydroxyethoxybenzoate), poly(ε-caprolactone), and random poly(2-hydroxyethoxybenzoate/e-caprolactone) copolymers were synthesized and characterized in terms of chemical structure and molecular mass. The thermal behavior was examined by DSC. All the samples appear as semicrystalline materials; the main effect of copolymerization was lowering in the amount of crystallinity and a decrease of melting temperature with respect to homopolymers. Flory's equation described well the T m-composition data. Amorphous samples (in the 20–100%2-hydroxyethoxybenzoate unit concentration range) obtained by quenching showed amonotonic decrease of the glass transition temperature T g as the content of caprolactone units is increased. The Wood's equation described the T g-composition data well.

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Abstract  

Environmentally compatible polymers such as poly(ε-caprolactone) (PCL) and polyurethane (PU) derivatives from PCL's were synthesized from saccharides, polysaccharides and lignins such as glucose, fructose, sucrose, cellulose, cellulose acetate, alcoholysis lignin, kraft lignin and sodium lignosulfonate. Flexible and rigid PU sheets and foams were also prepared by the reaction of OH groups of saccharides and lignins with isocyanates such as toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI). Glass transition temperatures (Tg's), cold-crystallization temperatures (Tcc's) and melting temperatures (Tm's) of saccharide- and lignin-based PCL's and PU's were determined by differential scanning calorimetry (DSC), and phase diagrams were obtained. Methods of controlling mechanical properties such as stress and elasticity of PU's through changing thermal properties such as glass transition temperature were established. Thermogravimetry (TG) and TG-Fourier transform infrared spectrometry (FTIR) were also carried out in order to analyze the degradation temperature and evolved gases from the above obtained polymers.

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189 Nishida, H., Tokiwa, Y. (1993) Distribution of poly(β-hydroxybutyrate) and poly(ε-caprolactone) aerobic degrading microorganisms in different environments. J. Environ. Polym. Degrad. 1

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]. Experimental Chemicals and Reagents High purity TCS was purchased from Bio Basic Canada Inc. (Markham Ontario, Canada). FBP was purchased from FDC limited (Mumbai, India). Poly-ε-caprolactone (PCL) with ̴ 14,000 molecular weight

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Interventional Medicine and Applied Science
Authors: Anand Maurya, Anurag Kumar Singh, Gaurav Mishra, Komal Kumari, Arati Rai, Bhupesh Sharma, Giriraj T. Kulkarni, and Rajendra Awasthi

LS : Curcumin-loaded poly (ε-caprolactone) nanofibres: Diabetic wound dressing with anti-oxidant and anti-inflammatory properties . Clin Exp Pharmacol Physiol 36 , 1149 – 1156 ( 2009 ) 10.1111/j.1440-1681.2009.05216.x

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