Documents disponibles écrits par cet auteur

Properties of poly(lactic acid)/poly(butylene adipate-co-terephthalate)/nanoparticle ternary composites / Jiang, Long in Industrial & engineering chemistry research, Vol. 48 N° 16 (Août 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 16 (Août 2009) . - pp. 7594–7602 Titre : Properties of poly(lactic acid)/poly(butylene adipate-co-terephthalate)/nanoparticle ternary composites Type de document : texte imprimé Auteurs : Jiang, Long, Auteur ; Bo Liu, Auteur ; Jinwen Zhang, Auteur Année de publication : 2009 Article en page(s) : pp. 7594–7602 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Poly(lactic  acid)  Flexible  poly(butylene  adipate-co-terephthalate)  Ternary  composites Résumé : Poly(lactic acid) (PLA) can be toughened by flexible poly(butylene adipate-co-terephthalate) (PBAT) at the cost of a certain degree of strength and modulus loss. In an attempt to achieve balanced overall properties, PLA ternary composites containing both PBAT and rigid nanoparticles, i.e., montmorillonite clay (MMT) or nanosized precipitated calcium carbonate (NPCC), were prepared by twin screw extrusion and subsequent injection molding. Mechanical testing demonstrated that the composites containing MMT exhibited higher tensile strength and modulus but lower elongation compared to the composites containing NPCC. Using maleic anhydride (MA) grafted PLA as a compatibilizer, the elongation of the ternary composites was substantially increased, possibly due to improved dispersion of the nanoparticles. The injection molded ternary composites were shown to have a skin−core layered structure. The skin and core layers were found to possess different microstructure, thermal behavior, and mechanical properties. The microstructure difference led to a sequential fracture behavior during tension testing: the fracture of the core layer was followed by the skin layer. The skin layer, with a higher degree of PLA chain alignment and conformational ordering than the core layer, exhibited a higher glass transition temperature, lower cold crystallization temperature, and a higher degree of perfection in crystalline structures. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900576f [article] Properties of poly(lactic acid)/poly(butylene adipate-co-terephthalate)/nanoparticle ternary composites [texte imprimé] / Jiang, Long, Auteur ; Bo Liu, Auteur ; Jinwen Zhang, Auteur . - 2009 . - pp. 7594–7602. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 16 (Août 2009) . - pp. 7594–7602 Mots-clés : Poly(lactic  acid)  Flexible  poly(butylene  adipate-co-terephthalate)  Ternary  composites Résumé : Poly(lactic acid) (PLA) can be toughened by flexible poly(butylene adipate-co-terephthalate) (PBAT) at the cost of a certain degree of strength and modulus loss. In an attempt to achieve balanced overall properties, PLA ternary composites containing both PBAT and rigid nanoparticles, i.e., montmorillonite clay (MMT) or nanosized precipitated calcium carbonate (NPCC), were prepared by twin screw extrusion and subsequent injection molding. Mechanical testing demonstrated that the composites containing MMT exhibited higher tensile strength and modulus but lower elongation compared to the composites containing NPCC. Using maleic anhydride (MA) grafted PLA as a compatibilizer, the elongation of the ternary composites was substantially increased, possibly due to improved dispersion of the nanoparticles. The injection molded ternary composites were shown to have a skin−core layered structure. The skin and core layers were found to possess different microstructure, thermal behavior, and mechanical properties. The microstructure difference led to a sequential fracture behavior during tension testing: the fracture of the core layer was followed by the skin layer. The skin layer, with a higher degree of PLA chain alignment and conformational ordering than the core layer, exhibited a higher glass transition temperature, lower cold crystallization temperature, and a higher degree of perfection in crystalline structures. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900576f

Reinforcing and toughening effects of bamboo pulp fiber on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) fiber composites / Jiang, Long in Industrial & engineering chemistry research, Vol. 49 N° 2 (Janvier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 2 (Janvier 2010) . - pp 572–577 Titre : Reinforcing and toughening effects of bamboo pulp fiber on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) fiber composites Type de document : texte imprimé Auteurs : Jiang, Long, Auteur ; Feng Chen, Auteur ; Qian, Jun, Auteur Année de publication : 2010 Article en page(s) : pp 572–577 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fiber  Composites  Hydroxybutyrate  Hydroxyvalerate. Résumé : In this work, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/bamboo pulp fiber composites were melt-compounded and injection-molded. Tensile, impact and dynamic mechanical properties of the composites were studied. In contrast to many other short natural fiber reinforced biocomposites which demonstrate decreased strain-at-break, impact toughness and tensile strength, the PHBV/bamboo pulp fiber composites displayed increased tensile strength and impact toughness, and maintained/increased strain-at-break. Microscopic study of the fracture surfaces revealed extensive fiber pullout in both tensile and impact tests. The fiber pullout suggests insufficient interfacial adhesion between the fiber and the matrix. The pullout process in the impact testing dissipated a significant amount of energy and hence substantially improved the impact toughness of the composites. With the improved interfacial adhesion provided by coupling agent polymeric diphenylmethane diisocyanate (pMDI), the strength and modulus of the composites were further increased. However, the toughness was decreased due to the inhibition of the fiber pullout. An acoustic emission test revealed a significantly different process of structural change for the composites with/without pMDI during tension test. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900953z [article] Reinforcing and toughening effects of bamboo pulp fiber on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) fiber composites [texte imprimé] / Jiang, Long, Auteur ; Feng Chen, Auteur ; Qian, Jun, Auteur . - 2010 . - pp 572–577. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 2 (Janvier 2010) . - pp 572–577 Mots-clés : Fiber  Composites  Hydroxybutyrate  Hydroxyvalerate. Résumé : In this work, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/bamboo pulp fiber composites were melt-compounded and injection-molded. Tensile, impact and dynamic mechanical properties of the composites were studied. In contrast to many other short natural fiber reinforced biocomposites which demonstrate decreased strain-at-break, impact toughness and tensile strength, the PHBV/bamboo pulp fiber composites displayed increased tensile strength and impact toughness, and maintained/increased strain-at-break. Microscopic study of the fracture surfaces revealed extensive fiber pullout in both tensile and impact tests. The fiber pullout suggests insufficient interfacial adhesion between the fiber and the matrix. The pullout process in the impact testing dissipated a significant amount of energy and hence substantially improved the impact toughness of the composites. With the improved interfacial adhesion provided by coupling agent polymeric diphenylmethane diisocyanate (pMDI), the strength and modulus of the composites were further increased. However, the toughness was decreased due to the inhibition of the fiber pullout. An acoustic emission test revealed a significantly different process of structural change for the composites with/without pMDI during tension test. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900953z

Synergetic effect of dual compatibilizers on in situ formed poly (lactic acid) / soy protein composites / Bo Liu in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6399-6406 Titre : Synergetic effect of dual compatibilizers on in situ formed poly (lactic acid) / soy protein composites Type de document : texte imprimé Auteurs : Bo Liu, Auteur ; Jiang, Long, Auteur ; Hongzhi Liu, Auteur Année de publication : 2010 Article en page(s) : pp. 6399-6406 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Composite  material  In  situ  Synergism Résumé : In this work, biobased poly(lactic acid) (PLA)/soy protein concentrate (SPC) composites were prepared by twin screw extrusion and injection molding. Poly(2-ethyl-2-oxamline) (PEOX) and polymeric methylene diphenyl diisocyanate (pMDI) were used sequentially as compatibilization agents to improve phase morphology and interfacial bonding. Properties of the PLA/SPC composites were significantly improved by the application of PEOX and pMDI. The SPC phase was refined and stretched into fine threads during processing under the compatibilization effect of PEOX. With only 0.5 part pMDI, the tensile strength of PLA/SPC composite increased significantly to approach that of pure PLA. With I part pMDI, the tensile strength was 6% higher than that of the neat PLA. Scanning electron micrographs evidenced enhanced interfacial adhesion between the two phases. Dynamic mechanical analysis tests revealed that the presence of pMDI enhanced the storage modulus of the composite, especially at temperatures above the glass-transition temperature of PLA, due to the strong interactions between the PLA and SPC phases after pMDI compatibilization. The compatibilized PLA/SPC blends also exhibited significantly reduced water uptakes. Fourier Transform Infrared Spectroscopy confirmed the occurrence of PLA grafting onto SPC molecules through pMDI compatibilization. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040395 [article] Synergetic effect of dual compatibilizers on in situ formed poly (lactic acid) / soy protein composites [texte imprimé] / Bo Liu, Auteur ; Jiang, Long, Auteur ; Hongzhi Liu, Auteur . - 2010 . - pp. 6399-6406. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6399-6406 Mots-clés : Composite  material  In  situ  Synergism Résumé : In this work, biobased poly(lactic acid) (PLA)/soy protein concentrate (SPC) composites were prepared by twin screw extrusion and injection molding. Poly(2-ethyl-2-oxamline) (PEOX) and polymeric methylene diphenyl diisocyanate (pMDI) were used sequentially as compatibilization agents to improve phase morphology and interfacial bonding. Properties of the PLA/SPC composites were significantly improved by the application of PEOX and pMDI. The SPC phase was refined and stretched into fine threads during processing under the compatibilization effect of PEOX. With only 0.5 part pMDI, the tensile strength of PLA/SPC composite increased significantly to approach that of pure PLA. With I part pMDI, the tensile strength was 6% higher than that of the neat PLA. Scanning electron micrographs evidenced enhanced interfacial adhesion between the two phases. Dynamic mechanical analysis tests revealed that the presence of pMDI enhanced the storage modulus of the composite, especially at temperatures above the glass-transition temperature of PLA, due to the strong interactions between the PLA and SPC phases after pMDI compatibilization. The compatibilized PLA/SPC blends also exhibited significantly reduced water uptakes. Fourier Transform Infrared Spectroscopy confirmed the occurrence of PLA grafting onto SPC molecules through pMDI compatibilization. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040395