Papers by Author: Bing Tao Wang

Abstract: The paper describes the production and the mechanical characteristics of composites made completely from renewable raw materials, the corn straw fiber and the biodegradable plastic, poly(lactic acid). The effect of straw fiber content on the mechanical properties of the composites was studied and the optimum mass fraction was 15%. To enhance the mechanical properties of the composites, two different methods were tested. Maleic anhydride as the compatilizer was introduced into the composites but the changes of the mechanical properties were small. While the other method, pre-treatment for straw fiber before blending, the mechanical properties increased obviously. The tensile strength and the impact strength were 35.6 MPa and 1.67 kJ/m2, respectively.

Abstract: In situ melt copolycondensation was proposed to prepare biodegradable copolyester nanocomposites based on degradable components poly(L-lactic acid) (PLA), rigid segments poly(butylene terephthalate) (PBT), and nanoparticles polyhedral oligomeric silsesquioxanes (POSS). The morphologies and dispersions of two POSS nanoparticles (POSS-NH₂ and POSS-PEG) in the copolyester PLABT matrix and their effects on the mechanical properties were investigated. The results demonstrated that the morphologies and dispersions of POSS-NH₂ and POSS-PEG showed quite different characteristics. POSS-PEG took better dispersion in the PLABT, while POSS-NH₂ had poor dispersions and formed crystalline microaggregates. Due to the good dispersion and strong interfacial adhesion of POSS-PEG with the matrix, the tensile strength and Young’s modulus were greatly improved from 6.4 and 9.6 MPa for neat PLABT up to 11.2 and 70.7 MPa for PLABT/POSS-PEG nanocomposite. Moreover, the incorporation of POSS-PEG could impart macromolecular chains good flexibility and improve the mobility of the chains, so the the elongation at break of PLABT/POSS-PEG nanocomposite dramatically increased from 190 to 350 % compared with neat PLABT.