Radiation grafting long-chain branch polylactic acid and preparation method thereof

Abstract

The invention discloses a radiation grafting long-chain branch polylactic acid which comprises a polylactic acid and 1,6-hexanediol diacrylate. The preparation method comprises the following steps: performing air blast drying on the polylactic acid, adding 1,6-hexanediol diacrylate in a molten PLA (Polylactic Acid) in a twin-screw extruder, extruding, air cooling, granulating, and performing the processing steps such as Co60 radiation irradiation under the oxygen limiting condition to obtain the long-chain branch polylactic acid. The production process is simple, the time for extruding and granulating is relatively short, the irradiation dose can be controlled, and the prepared long-chain branch polylactic acid is wide in molecular weight distribution, has relatively high storage moduli and relatively low loss angles, improves the strength of a melt made of a polylactic acid material, and is an environmental-friendly high-polymer material applied widely.

Description

Technical field [0001] The invention relates to the fields of biodegradable polymer materials and radiation processing, in particular to a radiation-grafted long-chain branched polylactic acid and a preparation method thereof. Background technique [0002] Polylactic acid (PLA), referred to as PLA, is a new generation of fully degradable polymer materials developed rapidly in the 1990s. It is made of L-lactic acid, a product of microbial fermentation, and polymerized by chemical synthesis. It is a kind of thermoplastic aliphatic resin. Polylactic acid has excellent biocompatibility and absorbability, non-toxic, non-irritating, it can be completely decomposed in a short period of time under the action of microorganisms, water, acid, alkali, etc. in nature, and the final product is CO 2 and H 2 O, no pollution to the environment, can be used as an environmentally friendly material to replace traditional polymer materials, and has received extensive attention and in-depth res...

AI Technical Summary

Problems solved by technology

However, this method is to produce products under high temperature and long-term conditions. Polylactic acid is easy to degrade under high temperature and long-term conditions. The added antioxidant will introduce new groups to polylactic acid, which is not conducive to ensuring the purity of the final product.

And the method that Chinese patent CN101735409A proposes is only applicable to the radiation modification of the PLA (molecular weight 5000-50000) of small molecular weight, is in order to improve the mechanical property and the thermal stability of small molecular weight PLA, and this method requires a long time to stay in the extruder. 0.5-3 hours, the residence time is longer; while PLA in the range of small molecular weight 5000-50000 has almost no strength, no processability, and no use value

Images