Documents disponibles écrits par cet auteur

Hydrophobic thermoplastic starches modified with polyester - based polyurethane microparticles / Yamei Leng in Industrial & engineering chemistry research, Vol. 50 N° 19 (Octobre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 19 (Octobre 2011) . - pp. 11130-11135 Titre : Hydrophobic thermoplastic starches modified with polyester - based polyurethane microparticles : effects of various diisocyanates Type de document : texte imprimé Auteurs : Yamei Leng, Auteur ; Yu Zhang, Auteur ; Xiaoxia Chen, Auteur Année de publication : 2011 Article en page(s) : pp. 11130-11135 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microparticle Résumé : It is critical to prepare ductile and hydrophobic modified starch material in an effective and environmentally friendly way. In this work, polyurethane prepolymers (PUPs) with various isocyanates were synthesized and mixed reactively with thermoplastic starches (TPS) in an intensive mixer to prepare modified TPS. The effects of the isocyanates on the structure and properties of the modified TPS were then investigated by using scanning electron microscope (ESEM), tensile tester, and contact angle meter. Results showed that mechanical properties ofthe modified TPS were improved with the increase in hydrophobicity of the isocyanate. 4,4'-Methylenedi-p-phenyl diisocyanate (MDI) was hydrophobic, the NCO groups in PUPs were not easily consumed by water when modified starch was prepared, leading to a significantly increased reaction of the NCO groups with starch. As the amount of urethane bonds between starch and PUP increased, the compatibility between the two polymers was also improved, resulting in the improvement of tensile properties. Isocyanates played an important role in improving the compatibility between the starch and PUP and the properties of the modified TPS. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24573311 [article] Hydrophobic thermoplastic starches modified with polyester - based polyurethane microparticles : effects of various diisocyanates [texte imprimé] / Yamei Leng, Auteur ; Yu Zhang, Auteur ; Xiaoxia Chen, Auteur . - 2011 . - pp. 11130-11135. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 19 (Octobre 2011) . - pp. 11130-11135 Mots-clés : Microparticle Résumé : It is critical to prepare ductile and hydrophobic modified starch material in an effective and environmentally friendly way. In this work, polyurethane prepolymers (PUPs) with various isocyanates were synthesized and mixed reactively with thermoplastic starches (TPS) in an intensive mixer to prepare modified TPS. The effects of the isocyanates on the structure and properties of the modified TPS were then investigated by using scanning electron microscope (ESEM), tensile tester, and contact angle meter. Results showed that mechanical properties ofthe modified TPS were improved with the increase in hydrophobicity of the isocyanate. 4,4'-Methylenedi-p-phenyl diisocyanate (MDI) was hydrophobic, the NCO groups in PUPs were not easily consumed by water when modified starch was prepared, leading to a significantly increased reaction of the NCO groups with starch. As the amount of urethane bonds between starch and PUP increased, the compatibility between the two polymers was also improved, resulting in the improvement of tensile properties. Isocyanates played an important role in improving the compatibility between the starch and PUP and the properties of the modified TPS. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24573311

Tough thermoplastic starch modified with polyurethane microparticles / Yu Zhang in Industrial & engineering chemistry research, Vol. 50 N° 21 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11906-11911 Titre : Tough thermoplastic starch modified with polyurethane microparticles : the effects of NCO content in prepolymers Type de document : texte imprimé Auteurs : Yu Zhang, Auteur ; Yan Huang, Auteur ; Xiaoxia Chen, Auteur Année de publication : 2011 Article en page(s) : pp. 11906-11911 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microparticle Résumé : In this work, polyurethane prepolymers (PUPs) with various NCO content proportions were synthesized and mixed reactively with a starch-water mixture to prepare modified thermoplastic starch (TPS) in an environmentally friendly way. The effects of polyurethane NCO content on the structure and/or properties of the modified TPS sheets were investigated. Results revealed that the reaction ratio of PUPs used for preparing the modified TPS was 99.8%, indicating that the PUPs were almost cross-linked to the starch matrix. With an increase of NCO content in PUP, the tensile strength of the modified TPS increased from 19.3 to 37.4 MPa, and the elongation from 1.7% to 17.2%. As the PUP's NCO content increased, the amount of urethane linkage between PU microparticles and the starch matrix would increase. In addition, the compatibility of the two polymers was also improved resulting in the improvement of tensile properties. The urethane linkage between PU and starch therefore played an important role in improving the toughness of the modified TPS. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697507 [article] Tough thermoplastic starch modified with polyurethane microparticles : the effects of NCO content in prepolymers [texte imprimé] / Yu Zhang, Auteur ; Yan Huang, Auteur ; Xiaoxia Chen, Auteur . - 2011 . - pp. 11906-11911. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11906-11911 Mots-clés : Microparticle Résumé : In this work, polyurethane prepolymers (PUPs) with various NCO content proportions were synthesized and mixed reactively with a starch-water mixture to prepare modified thermoplastic starch (TPS) in an environmentally friendly way. The effects of polyurethane NCO content on the structure and/or properties of the modified TPS sheets were investigated. Results revealed that the reaction ratio of PUPs used for preparing the modified TPS was 99.8%, indicating that the PUPs were almost cross-linked to the starch matrix. With an increase of NCO content in PUP, the tensile strength of the modified TPS increased from 19.3 to 37.4 MPa, and the elongation from 1.7% to 17.2%. As the PUP's NCO content increased, the amount of urethane linkage between PU microparticles and the starch matrix would increase. In addition, the compatibility of the two polymers was also improved resulting in the improvement of tensile properties. The urethane linkage between PU and starch therefore played an important role in improving the toughness of the modified TPS. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697507