A kind of preparation method of modified polylactic acid material

Abstract

The present invention provides a preparation method for modified polystraphy materials, which are aggregated for melting and solid -phase, including the following steps: step s1), to obtain prefabricated clustering by lactic acid, amino acid, and polymiol through melting polymerization;Also add a certain amount of catalyst; step s2), the pre -concentration of the step 1) is heated to the higher than the glass (TG), below the melting temperature (TM), add the epoxy diluent and the catalyst to continue the reaction to get what it is described as described.Modified polystrackic acid material; the condition is the average functional degree of hydroxyl group of polyol is 2.6‑3.2.The present invention has selected a specific raw material and its ratio, especially the average hydroxygenic energy of the polyol mixture, and obtained a degradable polystracking material with excellent comprehensive performance, the first to be slower after the degradation speed, and then the general polystumin material is overcome.The degradation speed cannot meet the defects of actual needs.

Description

technical field [0001] The invention relates to the field of polymer manufacturing, in particular to a preparation method and application of modified polylactic acid. Background technique [0002] Polylactic acid (PLA), also known as polylactide, is a polyester polymerized from lactic acid. Polylactic acid has excellent biodegradability, compatibility and absorbability. Polylactic acid is a non-toxic and non-irritating synthetic polymer material. Its raw material is lactic acid, which mainly comes from the fermentation of starch (such as corn and rice), and can also be obtained from cellulose, kitchen waste or fish body waste. PLA raw materials come from a wide range of sources, and the products made from it can be directly composted or incinerated after use, and finally can completely reduce CO 2 and H 2 O, to meet the requirements of sustainable development. The good transparency, certain toughness, biocompatibility and heat resistance of PLA are the main reasons for i...

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Problems solved by technology

Patent CN104861120 discloses an environmentally friendly and long-acting antibacterial polylactic acid material, which uses toxic reagents such as acrylamide and halogenated agents in its preparation, and it is inevitably used as a food utensil, which has great potential safety hazards

And its preparation method is complicated, and raw material is expensive, is not suitable for industrialized large-scale production

Chinese patent CN1317321A discloses a preparation method of polylactic acid resin. In this method, plasticizer is directly added to polylactic acid resin for melt mixing. The flexibility of polylactic acid can be effectively improved through traditional blending and plasticization, but there is a problem of plasticization. agent migration and permeation issues

The modified polylactic acid announced by CN101362853A and CN103467950A all adopt some organic substances as cross-linking agent, which is highly toxic, which limits the application of polylactic acid products in fields such as medical treatment and food

However, these amino acid copolymerization modification technologies often have the following defects: 1, the ring-opening polymerization of lactide is adopted, the raw materials are complicated, the cost is high, and it is not conducive to industrial production, and lactide; 2, SnCl is generally used 2 As a catalyst, it is impossible to completely eliminate the toxicity of tin. As a food-grade raw material, there are still potential safety hazards, and it cannot pass the market inspection with strict requirements for safety; 3. The ring-opening reaction will produce a racemization reaction, which is difficult to prepare high molecular weight polylactic acid

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