Completely-biodegrading low-mobility-plasticizer polylactic acid material and preparation method thereof

Abstract

The invention discloses a completely-biodegrading low-mobility-plasticizer polylactic acid material and a preparation method thereof. The preparation method includes following steps: (1) blending glycerin and lactic acid according to a molar ratio of 1:0.5-10; (2) adding a water-carrying agent accounting for 2-15 wt% of a total mass and a catalyst accounting for 0.1-5 wt% of the mass of the glycerin to obtain a mixed material, stirring the mixed material at 130-250 DEG C for 3-24 h, and removing the water-carrying agent and removing micromolecules which are not reacted at 50-220 DEG C under a vacuum degree of 0.5-20 kPa to obtain a low-mobility plasticizer; and (3) adding 100 parts of polylactic acid and 5-90 parts of the low-mobility plasticizer to a macromolecule blend processing device and performing a blending process at 130-220 DEG C for 3-20 min to obtain the completely-biodegrading low-mobility-plasticizer polylactic acid material. The polylactic acid material, which is modified by the low-mobility plasticizer, has high tensile strength and elongation at break, is excellent in flexibility, is low in mobility of plasticizer, is good in biodegradability, and has wide application prospects in the fields of packaging materials, medicinal and hygienic materials, daily necessities and automobile part materials.

Description

technical field [0001] The invention relates to a polylactic acid material with a completely biodegradable low-migration plasticizer and a preparation method thereof, belonging to the field of polymer materials and its preparation. Background technique [0002] Among biodegradable polymer materials, polylactic acid (PLA) is considered to be the most promising one, and has attracted extensive attention from academia and industry in recent years. Polylactic acid is an ideal substitute for traditional petroleum-based plastics. Compared with traditional petroleum-based plastics, its main features: (1) Bio-based, low-carbon effect: raw materials are derived from bio-based renewable resources, reducing the consumption of petrochemical resources According to the ISO13432 standard, every ton of polylactic acid used can reduce 2.2 tons of carbon dioxide emissions. (2) Completely biodegradable, can alleviate the problem of white pollution: polylactic acid can be 100% biodegradable, c...

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Problems solved by technology

Chinese patent CN1687233 discloses a method for plasticizing and modifying polylactic acid with tributyl citrate, but tributyl citrate has strong mobility in polylactic acid, which is not conducive to the long-term use of materials; Japanese patent JP2008-069299 discloses A method of plasticizing and modifying polylactic acid with polyglycerol fatty acid ester, the mechanical properties of this polylactic acid product will gradually decrease at room temperature

At present, the modification methods reported in these patent documents and non-patent literature have not completely solved the problems of mechanical properties, migration resistance and complete biodegradability of modified polylactic acid materials.

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