Documents disponibles écrits par cet auteur

Novel biodegradable and double crystalline multiblock copolymers comprising of poly (butylene succinate) and poly (E - caprolactone) / Liuchun Zheng in Industrial & engineering chemistry research, Vol. 51 N° 21 (Mai 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7264-7272 Titre : Novel biodegradable and double crystalline multiblock copolymers comprising of poly (butylene succinate) and poly (E - caprolactone) : Synthesis, characterization, and properties Type de document : texte imprimé Auteurs : Liuchun Zheng, Auteur ; Chuncheng Li, Auteur ; Zhaodong Wang, Auteur Année de publication : 2012 Article en page(s) : pp. 7264-7272 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Biodegradable  Crystalline  Copolymers Résumé : A series of double crystalline multiblock copolymers composed of poly(butylene succinate) (PBS) and poly(ε-caprolactone) (PCL) have been successfully synthesized with hexamethylene diisocyanate (HDI) as a chain extender. The copolymers were systematically characterized by 1H NMR, GPC, TGA, DSC, WAXD, and mechanical testing. The results indicate that the PBS segment is immiscible with the PCL segment in the amorphous region. The copolymers follow a two-stage degradation behavior, and thermal stability increases with increasing PBS content. PBS and PCL in the copolymers crystallize and melt separately. The mechanical properties of the copolymers can be conveniently adjusted from rigid plastics to flexible elastomers by changing the feed composition. The impact strength is substantially improved by the incorporation of the PCL segment. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300576z [article] Novel biodegradable and double crystalline multiblock copolymers comprising of poly (butylene succinate) and poly (E - caprolactone) : Synthesis, characterization, and properties [texte imprimé] / Liuchun Zheng, Auteur ; Chuncheng Li, Auteur ; Zhaodong Wang, Auteur . - 2012 . - pp. 7264-7272. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7264-7272 Mots-clés : Biodegradable  Crystalline  Copolymers Résumé : A series of double crystalline multiblock copolymers composed of poly(butylene succinate) (PBS) and poly(ε-caprolactone) (PCL) have been successfully synthesized with hexamethylene diisocyanate (HDI) as a chain extender. The copolymers were systematically characterized by 1H NMR, GPC, TGA, DSC, WAXD, and mechanical testing. The results indicate that the PBS segment is immiscible with the PCL segment in the amorphous region. The copolymers follow a two-stage degradation behavior, and thermal stability increases with increasing PBS content. PBS and PCL in the copolymers crystallize and melt separately. The mechanical properties of the copolymers can be conveniently adjusted from rigid plastics to flexible elastomers by changing the feed composition. The impact strength is substantially improved by the incorporation of the PCL segment. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300576z

Novel unsaturated aliphatic polyesters / Liuchun Zheng in Industrial & engineering chemistry research, Vol. 51 N° 43 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14107-14114 Titre : Novel unsaturated aliphatic polyesters : Synthesis, characterization, and properties of multiblock copolymers composing of poly(butylene fumarate) and poly(1,2-propylene succinate) Type de document : texte imprimé Auteurs : Liuchun Zheng, Auteur ; Zhaodong Wang, Auteur ; Chuncheng Li, Auteur Année de publication : 2013 Article en page(s) : pp. 14107-14114 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Aliphatic  compound Résumé : Widespread application of biodegradable polyesters is restrained by various disadvantages such as inadequate thermomechanical properties, high cost, and lack of reactive sites for further modification. Poly(butylene fumarate) (PBF), as a novel and low-cost aliphatic polyester, possesses good physical properties and reactive double bonds along with the polymer backbones which can be potentially modified to endow the polyester with specific properties. However, the biodegradation rate of PBF is too slow to meet the requirement of practical application. In this contribution, amorphous poly(1,2-propylene succinate) (PPS) was copolymerized with PBF to decrease the crystallinity (Xc) and accelerate the biodegradability of PBF via chain-extension with diisocyanate. The chemical structures of the copolymers were confirmed by 1H NMR spectra and gel permeation chromatography (GPC). The crystal structure and physicochemical properties were investigated by wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), mechanical testing, and enzymatic degradation in detail. Both the impact strength and degradation rate of the copolymers are effectively improved by the introduction of amorphous PPS; while the melting point (Tm) and crystallization temperature (Tc) are hardly reduced by the incorporation of PPS. The novel polymer may be directed used as low-cost biodegradable materials or be further functionalized with special properties for particular applications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593338 [article] Novel unsaturated aliphatic polyesters : Synthesis, characterization, and properties of multiblock copolymers composing of poly(butylene fumarate) and poly(1,2-propylene succinate) [texte imprimé] / Liuchun Zheng, Auteur ; Zhaodong Wang, Auteur ; Chuncheng Li, Auteur . - 2013 . - pp. 14107-14114. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14107-14114 Mots-clés : Aliphatic  compound Résumé : Widespread application of biodegradable polyesters is restrained by various disadvantages such as inadequate thermomechanical properties, high cost, and lack of reactive sites for further modification. Poly(butylene fumarate) (PBF), as a novel and low-cost aliphatic polyester, possesses good physical properties and reactive double bonds along with the polymer backbones which can be potentially modified to endow the polyester with specific properties. However, the biodegradation rate of PBF is too slow to meet the requirement of practical application. In this contribution, amorphous poly(1,2-propylene succinate) (PPS) was copolymerized with PBF to decrease the crystallinity (Xc) and accelerate the biodegradability of PBF via chain-extension with diisocyanate. The chemical structures of the copolymers were confirmed by 1H NMR spectra and gel permeation chromatography (GPC). The crystal structure and physicochemical properties were investigated by wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), mechanical testing, and enzymatic degradation in detail. Both the impact strength and degradation rate of the copolymers are effectively improved by the introduction of amorphous PPS; while the melting point (Tm) and crystallization temperature (Tc) are hardly reduced by the incorporation of PPS. The novel polymer may be directed used as low-cost biodegradable materials or be further functionalized with special properties for particular applications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593338