| 摘要 |
<p>A fully degradable and a compostable polyester based blend that is free from nondegradable organic or inorganic additives comprises (i) not less than 70% by weight of polylactic acid, (ii) between 0.5-15% by weight of a first polyester, and (iii) between 0.5-15% by weight of a second polyester wherein the second polyester has a greater average molecular weight than the first polyester. Also disclosed is the combination of polylactide, first and second polyesters where the second polyester has a higher melt flow rate (MFR) than the first. The thermal properties of the present blend are configured for optimised flow rate during process moulding via a 'flow rate enhancing component' being a relative low molecular weight biodegradable polyester. The blend also provides a resultant moulded article having the appropriate mechanical, physical and chemical properties including greatly improved toughness over existing PLA based blends. This is achieved by incorporating a `toughening component' within the blend being a relatively high molecular weight component relative to the flow rate enhancing component. The preferred embodiment consist of at least 80% by weight of PLA, up to 10% polybutylene succinate (PBS) and up to 10% polycaprolactone (PCL).</p> |
