Method for preparing thermal stable polyoxymethylene copolymer

A copolyformaldehyde and thermally stable technology, which is applied in the preparation of thermally stable copolyformaldehyde, in the field of end group stabilization treatment in the post-treatment of copolyformaldehyde powder, can solve the problem of low production efficiency, difficult complete hydrolysis of unstable end groups, and alkaline medium. Problems such as large consumption

Inactive Publication Date: 2009-02-04
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

In this method, the polymer suspended in alkaline water is insoluble, infusible, and it is difficult to completely hydrolyze the unstable end group. In addition, the amount of alkaline medium used in the treatment process is large, the recovery process is complicated, and the production efficiency is low. It is not suitable for large-scale industrial production.

Method used

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  • Method for preparing thermal stable polyoxymethylene copolymer
  • Method for preparing thermal stable polyoxymethylene copolymer

Examples

Experimental program
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Effect test

Embodiment 1

[0036] Without adding any additives, the acetal copolymer powder is directly melted and extruded by a vented twin-screw extruder, the processing temperature is 180°C-220°C, the pressure in the vacuum zone is 0.01-0.2bar, and the screw speed is 120 rpm / min, dried at 80°C for 4 hours after granulation.

Embodiment 2

[0038] 10Kg of polyoxymethylene powder and 30 g of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester were uniformly mixed and extruded using a vented twin-screw extruder. The treatment temperature is 180°C-220°C, the pressure in the vacuum zone is 0.01-0.2 bar, the screw speed is 120 rpm, and the pellets are dried at 80°C for 4 hours.

Embodiment 3

[0040] Mix 10Kg of polyoxymethylene powder, 30g of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester, 5g of magnesium hydroxide, and 10g of deionized water, and then use the exhaust type The twin-screw extruder is melted and extruded, the processing temperature is 180°C-220°C, the pressure in the vacuum zone is 0.01-0.2bar, the screw speed is 120 rpm, and it is dried at 80°C for 4 hours after granulation.

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Abstract

The invention provides a method for preparing thermostable polyformaldehyde, which is characterized in that an exhaust double screw extruder is used for heating polyformaldehyde to the temperature between the melting point of a polymer and 240 DEG C for melt extrusion; subsequently, the extruded product is treated; alkaline matter is added to promote instable end groups to be decompounded quickly during the treatment so that the end groups of the polyformaldehyde are stabilized, thus getting a copolymerized formaldehyde resin having high thermostability and releasing little formaldehyde.

Description

technical field [0001] The invention relates to a method for preparing thermally stable polyoxymethylene copolymer, in particular to a method for stabilizing terminal groups in the post-treatment of polyoxymethylene copolymer powder, and belongs to the field of polymer preparation and processing. Background technique [0002] Polyoxymethylene copolymer is a thermoplastic engineering plastic with excellent comprehensive properties, which has been widely used in automobiles, electrical and electronic instruments, office equipment, construction machinery and other fields. Especially as a variety of power transmission parts (gears, crankshafts, bearings, etc.), it has an irreplaceable important position. [0003] In the industry, trioxane is usually used as a monomer, and the comonomer is used in the initiator BF 3 ·OEt 2 Under the action of cationic ring-opening polymerization to obtain polyoxymethylene resin. Among them, the comonomer is a cyclic acetal or cyclic ether comp...

Claims

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Application Information

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IPC IPC(8): C08G2/30B29B9/00B29C47/92B29C48/40B29C48/92
CPCB29C47/92B29C48/92B29C2948/92704B29C48/40B29C2948/9259B29C2948/92885B29C2948/92895
Inventor 向明杨锋刘国刚蔡燎原蓝方
Owner SICHUAN UNIV
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