Preparation of polylactide by ring-opening polymerisation of lactide

This study was about to produce high molecular weight polylactide (PLA) with via ring-opening polymerisation. Ring-opening polymerisation PLA in this study as accomplished using tin(II)octoate as the catalyst with addition of small amount of luaryl alcohol as the co-catalyst. The effects of reaction temperature and pressure on synthesised polylactide were investigated. As-synthesised products were characterised by H-1-NMR, FT-IR and MALDI-TOF mass spectrometry. The results showed that as-synthesised products were very similar to PLA characteristics reported previously by other researchers. The melting temperature of polylactide was in the range of 130-145 degrees C. Furthermore, as-synthesised polylactide could not be dissolved completely in many solvents there are just some parts of PLA can be dissolved. Therefore, as-synthesised polylactide could expect to be high molecular weight. In addition, soluble part of polylactide in THF was then characterised by GPC. Moreover, insoluble polylactide was filtered and weighed. With increasing temperature and reducing pressure more residues were collected.