"DIFFUSED REFLECTION OF MICRO-CELLULAR FOAMED POLYLACTIC ACID (PLA)"
DIFFUSED REFLECTION OF MICRO-CELLULAR FOAMED POLYLACTIC ACID (PLA) Jung-hwan Seo1, Sung Woon Cha2,*, Hak Bin Kim1 1 Department of Mechanical Engineering, Yonsei University, Seoul 120-749, Korea 2 School of Mechanical Engineering, Yonsei University, Seoul 120-749, Korea ABSTRACT Microcellular foamed plastics have significantly contributed to the plastics industry by achieving weight reduction of the product and material cost savings. Limitations in petroleum resource reserves have lately propelled active research into foaming process. In particular, the extremely small cell size at less than 10μm and higher density for microcellular foaming process compared to the existing chemical foaming keeps its mechanical property decline small. In short, microcellular foamed plastics keep mechanical property decline to a minimum and deliver lightweight products. The research into microcellular foaming process thus far has focused on elevating foaming expansion ratio or keeping off mechanical property decline such as intensity. One of the most important trends in the polymer field nowadays is the replacement of petroleum-based polymers with bio-based ones. Among bio- based polymers, polylactic acid (PLA) and thermoplastic starch (TPS) are very attractive due to their availability, relatively low cost and their appealing physical and mechanical properties. This paper uses polylactic acid (PLA), which is a biodegradable material, to carry out foaming and describes research outcome of foamed PLA’s optical properties. Desorption time was controlled during the test to change * To whom correspondence should be addressed E-mail: (Sung Woon Cha) firstname.lastname@example.org Phone: +82 - +2 - 2123 – 4811; Fax # : +82 - +2 - 364 - 9364 cell morphology and monitor the subsequent changes in diffused reflectivity. This research is the first-ever attempt to suggest new application areas of PLA, poor in mechanical properties.