폴리락타이드/개질된 실리카 나노복합소재의 다공성 구조체 제조

Abstract

Polylactide (PLA) is a bio-based aliphatic polyester derived from renewable resources which is one of the most promising polymers capable of replacing petroleum-based polymers. PLA/modified silica (m-silica) nanocomposites were prepared using a melt compounding process employing a twin-screw extruder and PLA/m-silica nanocomposites with a m-silica contents of 0, 0.5, 1, 2, 3, and 5 wt% were obtained. The m-silica nanoparticles act as thermal and mechanical reinforcement of PLA. In addition, microcellular foaming using PLA nanocomposites can improve the impact strength, crystallinity, fatigue life, toughness, thermal stability and insulating properties of PLA. In this research, microcellular PLA/m-silica nanocomposite foams were prepared in a batch process using supercritical carbon dioxide as physical blowing agent. The resultant foams were observed by scanning electron microscopy (SEM) and average cell diameter and cell density were calculated using SEM micrographs. The incorporation of m-silica nanoparticles into the PLA matrix has the effect of decreasing the cell diameter and increasing the cell uniformity and cell density. These results are considered to be the result of the cell nucleation effect of m-silica nanoparticles in the foaming process of PLA.