Improving polylactide/starch biocomposites by grafting polylactide with acrylic acid--characterization and biodegradability assessment.
In this article, the properties of a polylactide and starch composite (PLA/starch) and an acrylic acid grafted polylactide and starch composite (PLA-g-AA/starch) were compared. The composite containing PLA-g-AA was found to have much better dispersion and homogeneity of starch in the polymer matrix than the composite containing PLA, indicating better compatibility between the two phases. Better mechanical and thermal properties of the PLA-g-AA/starch composite, notably an increase in tensile strength and elongation at breakpoint, evidenced its superiority to the PLA/starch composite. Furthermore, the lower viscosity of PLA-g-AA/starch makes it easier to process than PLA/starch. Weight loss on exposure to a soil environment over a period of three months showed that the starch in the composites was almost completely biodegradable, even at a high degree of substitution (60 wt.-% starch). After three months in soil, a reduction in the mechanical properties of the blends was observed, especially in those with higher starch contents.
Wu
Chin-San
CS
Department of Biochemical Engineering and Graduate Institute of Environmental Polymer Materials, Kao Yuan Institute of Technology, Kaohsiung County, Taiwan 82101, Republic of China. cws1222@cc.kyit.edu.tw
D000179:Acrylates / Q000737:chemistry; D001673:Biodegradation, Environmental; D002152:Calorimetry, Differential Scanning; D011091:Polyesters / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D014961:X-Ray Diffraction
D000179:Acrylates; D011091:Polyesters; C033616:poly(lactide); D013213:Starch; C036658:acrylic acid