This paper describes the evaluation of the mechanical properties and flame retardancy on bio-based polymer compounds of Poly(lactic acid) (PLA) and Polyamide 11 (PA 11). A compounding technology and mechanical properties of PLA and PA 11 using a compatibilizer were firstly studied to improve the thermal resistance and the impact strength of PLA. Some compositions of PLA/PA 11 blends using a compatibilizer were investigated. After some flame retardants which were not halogenated and toxic materials were blended to the composition of PLA/PA 11/compatibilizer, the mechanical properties and flame retardancy were also evaluated as compared with the commercialized PLA and Polycarbonate (PC) alloy. The flammability test was conducted with the multi-cone calorimeter to obtain the relation between the heat release rate or the integrated heat release value and the combustion time. The PLA/PA 11/compatibilizer containing the flame retardant will be applicable for the substitution of commercialized materials of PLA and PC. The compatibilizer and flame retardancy technology were also applied for high-performance polymer alloys.

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The brittle fracture of the isotactic polypropylene (i-PP) injection molded sheet in the falling weight impact test is caused by the cracks formed along the orientation direction of the surface layer. The fracture of the i-PP sheet takes place even at room temperature at low displacement. It was well known that the i-PP involving the elastomer phase possesses enhanced toughness.
In this study, toughening mechanism of the block polypropylene (block-PP) was examined especially for the falling weight impact test at-30°C. In the block-PP sheet, the plastic deformation zone was formed in the surface layer and grew stably towards the inside of the sheet. The voids where the elastomer phase existed were found to be deformed. The aspect ratio of the voids increased from 1.42 to 2.25 after the impact test. As for the toughening mechanism of the block-PP sheet at low temperature, it was proposed that the i-PP phase between the elastomer phases is plastically deformed by releasing the restraint strain due to the Poisson's contraction between the elastomer phases.

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