Preparation method of polyacetal resin

A technology of polyacetal resin and acetals, which is applied in the field of polyacetal resin and its preparation, can solve the problems of urgent development of inactivation process, reduction of mechanical properties of polyacetal resin, limitation of application scenarios, etc., to achieve effective splicing, The effect of simple inactivation process and simple process operation

Active Publication Date: 2020-08-04
WANHUA CHEM GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the addition of high nitrogen-containing substances will reduce the mechanical properties of polyacetal resin to a certain extent, limiting its application scenarios
[0004] Although there are a lot of work on the screening of comonomers and

Method used

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  • Preparation method of polyacetal resin
  • Preparation method of polyacetal resin

Examples

Experimental program
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Effect test

Embodiment 1

[0062] First, a certain amount of phosphotungstic acid is dissolved in methyl formate to obtain a solution with a concentration of 0.1wt%; paraformaldehyde, the methyl formate solution of phosphotungstic acid as a polymerization catalyst, and formaldehyde as a chain transfer agent Acetal and 1,3-dioxolane as a comonomer were supplied to the first continuous stirring and kneading type reactor (manufactured by List, Co-Rotating Processor (CRP) series: diameter 60mm , L / D (length-to-diameter ratio) = 18) continuous supply of the main feeding port, at 80 ° C continuous polymerization reaction. When the polymerization conversion rate is 60%, a mixed solution of pentaerythritol tetraglycidyl ether: 1,3-dioxolane = 1:1.5 is put into the feeding port at the rear of the reactor at 500g / h, and the mixture is added at 80 ℃ for further polymerization to obtain crude polyacetal powder.

[0063] Put the crude polyacetal powder and the deactivator sulfamethoxazole in a ratio of 100:1, that ...

Embodiment 2

[0069] The polyacetal resin is prepared by the method in Example 1, the difference is that when the polymerization conversion rate is 75%, it is pentaerythritol tetraglycidyl ether: 1 , 3-dioxolane=1:4 mixture; the temperature of the first continuous stirring and kneading reactor was changed from 80°C to 85°C; the temperature of the second continuous stirring and kneading reactor was changed from 100°C to 120°C , the rotation speed was changed from 30rpm to 50rpm, and the residence time was changed from 3min to 5min; the deactivator was replaced by 5-phenyl-1,3,4-oxadiazole-2-thiol from sulfamethoxazole; the deactivator and The ratio of crude polyacetal powder changed from 1:100 to 1:500.

Embodiment 3

[0071] The polyacetal resin is prepared by the method in Example 1, the difference is that when the polymerization conversion rate is 70%, it is pentaerythritol tetraglycidyl ether: 1 , 3-dioxolane=1:0.25 mixture; the temperature of the first continuous stirring and kneading reactor was changed from 80°C to 90°C; the temperature of the second continuous stirring and kneading reactor was changed from 100°C to 130°C , the rotation speed was changed from 30rpm to 60rpm, the residence time was changed from 3min to 8min; the ratio of deactivator to crude polyacetal powder was changed from 1:100 to 1:1000. The vacuum degree of each vacuum zone was replaced by 5 mbar to 10 mbar.

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Abstract

The invention provides a preparation method of polyacetal resin. The preparation method comprises the following steps: trioxymethylene, comonomer cyclic ether and/or cyclic acetal, glycidyl ether withat least two epoxy groups and an acetal chain transfer agent initiate a polymerization reaction through a heteropolyacid catalyst, and then react with an inactivator sulfur-containing functional group oxazole derivative and are extruded to obtain a product. The effective access of glycidyl ether to a polyacetal main chain can be realized by adding cyclic ether and/or a mixture of cyclic acetal and glycidyl ether with at least two epoxy groups in a specific stage of a polymerization reaction through a simple process; in addition, by improving the inactivation process, the material is mixed with an inactivator sulfur-containing functional group oxazole derivative and then subjected to reactive extrusion, so that the thermal stability and various mechanical properties of the polyacetal resinare improved.

Description

technical field [0001] The invention relates to a polyacetal resin and a preparation method thereof, belonging to the technical field of polymer materials. Background technique [0002] Polyacetal in the traditional sense is a thermoplastic crystalline engineering plastic with no side chains and excellent comprehensive properties. It has high rigidity and strong creep resistance, and is widely used in the fields of machinery, electronics and electricity. However, due to its special C-O main chain structure, polyacetal will inevitably have unstable hydroxyl ends during the synthesis process, resulting in a "zipper-type" formaldehyde removal reaction in the main chain during processing and molding, resulting in formaldehyde. Application of polyacetal resin. The use of glycidyl ether comonomers with multiple epoxy groups to generate cross-linking within the polymer and reduce the content of unstable terminals in polyacetal resins is one of the main directions developed by rese...

Claims

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Application Information

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IPC IPC(8): C08G2/22C08L59/04
CPCC08G2/22C08L59/04
Inventor 徐一麟杨晓珂王大林刘彪陈海波
Owner WANHUA CHEM GRP CO LTD
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