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Method for preparing branching or micro-cross-linking polylactic acid by one kettle

A micro-crosslinking, polylactic acid technology, applied in the field of preparing branched or micro-crosslinking polylactic acid, can solve the problems of solvent toxicity, limited product application, and product molecular weight is not too high, and achieves the effect of reducing production costs

Inactive Publication Date: 2009-11-25
BEIJING UNIV OF CHEM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Among them, the product prepared by the melt polycondensation method is relatively pure, but the molecular weight of the obtained product is not too high, which needs to be improved urgently; the solution azeotropic method introduces a large amount of solvent, which increases the cost, and the solvent itself has certain toxicity, which limits the application of the product

Method used

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  • Method for preparing branching or micro-cross-linking polylactic acid by one kettle
  • Method for preparing branching or micro-cross-linking polylactic acid by one kettle
  • Method for preparing branching or micro-cross-linking polylactic acid by one kettle

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Add 475 g of D, L-lactic acid, 4.4874 g of pentaerythritol, 9.6334 g of adipic acid, and 3.2414 g of stannous octoate into a 1.5 L reaction kettle equipped with temperature control, stirring, nitrogen gas introduction pipe and vacuum pump, and feed Nitrogen for 10 minutes, heated to 150 ° C for 3 hours with stirring and dehydration. Then raise the temperature to 180°C, continue to stir, turn on the vacuum pump, and gradually reduce the system pressure to less than 1000Pa within two hours, and continue to reduce the pressure until it reaches 100Pa. Start timing when the system temperature is 180° C., polycondensate for 5 hours and discharge to obtain polylactic acid with a weight-average molecular weight of 58,600.

[0028] Calculation of the average functionality of the system: 1) lactic acid, 5.27778mol; pentaerythritol, 0.03296mol; adipic acid, 0.06592mol;

[0029] 2) Average functionality f ‾ = ...

Embodiment 2

[0031] Add 475 g of D, L-lactic acid, 4.4712 g of pentaerythritol, 9.6340 g of adipic acid, and 3.5734 g of stannous octoate into a 1.5 L reaction kettle equipped with temperature control, stirring, nitrogen gas introduction pipe and vacuum pump, and feed Nitrogen for 10 minutes, heated to 150 ° C for 3 hours with stirring and dehydration. Then raise the temperature to 180°C, continue to stir, turn on the vacuum pump, and gradually reduce the system pressure to less than 1000Pa within two hours, and continue to reduce the pressure until it reaches 100Pa. Start counting when the system temperature is 180° C., polycondensate for 6 hours and discharge to obtain polylactic acid with a weight average molecular weight of 78,400.

[0032] Calculation of the average functionality of the system: 1) lactic acid, 5.27778mol; pentaerythritol, 0.03284mol; adipic acid, 0.06592mol;

[0033] 2) Average functionality f ‾ = ...

Embodiment 3

[0035] Add 475 g of D, L-lactic acid, 4.4868 g of pentaerythritol, 9.6352 g of adipic acid, and 3.3216 g of stannous octoate into a 1.5 L reaction kettle equipped with temperature control, stirring, nitrogen gas introduction pipe and vacuum pump, and feed Nitrogen for 10 minutes, heated to 150 ° C for 3 hours with stirring and dehydration. Then raise the temperature to 180°C, continue to stir, turn on the vacuum pump, and gradually reduce the system pressure to less than 1000Pa within two hours, and continue to reduce the pressure until it reaches 100Pa. Start timing when the system temperature is 180° C., polycondensate for 8 hours and discharge to obtain polylactic acid with a weight average molecular weight of 125,700.

[0036] Calculation of the average functionality of the system: 1) lactic acid, 5.27778mol; pentaerythritol, 0.03296mol; adipic acid, 0.06593mol;

[0037] 2) Average functionality f ‾ = ...

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Abstract

The invention discloses a method for preparing branching or micro-cross-linking polylactic acid by one kettle. The average functionality degree of the system can be controlled by adding dihydroxy ethylformic acid and so on other components, a high molecular weight polylactic acid can be prepared by melting polycondensation; the average functionality degree can be controlled by theoretical calculation, the polycondensation reaction degree can be controlled during polymerization, thereby controlling the polylactic acid molecular weight; the product toughness can be improved by adding soft segment such as tetrahydrofuran polyether. The invention can obtain high molecular weight polylactic acid with strong toughness by reasonable designed prescription. Moreover, the preparing method of the invention is simple, the costs are low, the polymerization process is easy to control, under the precondition without influencing the processing performance, the high molecular weight polylactic acid product can be obtained, the method is suitable for the popularization of the polylactic acid product.

Description

technical field [0001] The invention belongs to the field of polymer materials, and in particular relates to a method for preparing branched or slightly cross-linked polylactic acid in one kettle. Background technique [0002] With the development of society, the price of crude oil on which the chemical industry depends remains high, and with the extensive use, the amount of oil available for extraction in the world is decreasing year by year. At the same time, various social and environmental problems such as pollution are likely to occur during the use and demise of petroleum products. The development of green and environmentally friendly general-purpose materials, especially the renewable raw materials, has become an urgent problem to be solved by the chemical and material industries. [0003] Polylactic acid (PLA) is a widely researched biodegradable material. Its raw material lactic acid can be obtained by biological fermentation, and the final product can be returned...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G63/60C08G63/80
CPCY02P20/582
Inventor 付志峰曹鼎石艳李从举
Owner BEIJING UNIV OF CHEM TECH