Levorotatory polylactic acid traversing column crystals and preparation method therefor

Abstract

The invention relates to levorotatory polylactic acid traversing column crystals. The levorotatory polylactic acid traversing column crystals comprise the following ingredients: 85-95% of levorotatory polylactic acid and 5-15% of levorotatory polylactic acid fibers. The preparation method comprises the following steps: firstly, levorotatory polylactic acid fibers are subjected to vacuum drying for 5-8h at a temperature of 130-150 DEG C, and levorotatory polylactic acid is subjected to vacuum drying for3-7h at a temperature of 130-150 DEG C; secondly, the polylactic acid processed in the first step is heated to 180-200 DEG C, and the state is kept for 10min; thirdly, the polylactic acid fibers processed in the first step are introduced to the polylactic acid body with an initial concentration of 0.01-0.02g/ml processed in the second step at a temperature of 130-150 DEG C; fourthly, the products in the third steps are annealed to 110-130 DEG C rapidly, the state is kept for 30-180min, and thus the products are crystallized fully; fifthly, the products after full crystallization in the fourth step are taken out and cooled to the room temperature. The preparation method is simple and easily available, the cost is low, industrial production is hopeful, and the levorotatory polylactic acid traversing column crystals have great potential economic benefits.

Description

technical field [0001] The invention belongs to the technical field of polymer material preparation, and in particular relates to a cross-column crystal of L-polylactic acid and a preparation method thereof. Background technique [0002] Polylactic acid (PLA) is a degradable linear aliphatic polyester, which is derived from renewable biological resources (such as potatoes, corn, etc.), so it has excellent biodegradability and can be decomposed into carbon dioxide and water under natural conditions. Harmless to living organisms and the environment. As its optical isomer, in addition to the above-mentioned advantages, poly-L-lactic acid (PLLA) also has excellent properties that other optical isomers of poly-lactic acid do not have. Only poly-L-lactic acid (PLLA) has physiological activity on the human body and can It is used in medicine, food and other fields. As a crystalline polymer, it also has good mechanical properties and can realize industrial production. However, the...

AI Technical Summary

Problems solved by technology

However, the shortcomings of poly-L-lactic acid, such as hard and brittle, poor toughness and thermal stability, limit its good application prospects, making it difficult to apply in industrialization. - Lactic acid's excellent properties such as degradation performance and physiological activity have adversely affected its application as a bioactive material in medicine, food and other fields

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