Polycarbosilane with high molecular weight and high linearity and its preparation method and application

A technology of polycarbosilane and high molecular weight, which is applied in the field of polycarbosilane with high molecular weight and high linearity and its preparation, can solve the problems of low softening point, low strength and low yield of silicon carbide fibers, and achieve good textile performance, Effect of narrow molecular distribution and high softening point

Active Publication Date: 2021-06-29
江西信达航科新材料科技有限公司
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the current yield of synthesizing PCS precursors is low, and the synthesis cost of polycarbosilane is high; in addition, the molecular weight of PCS is difficult to increase, and the softening point is low, which leads to the low strength and molecular branching degree of the silicon carbide fibers prepared therefrom. Seriously, the spinnability of silicon carbide fiber is poor

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0022] The present invention provides a kind of preparation method of polycarbosilane with high molecular weight and high linearity, comprising the following steps:

[0023] S1: Put polydimethylsilane (PDMS) in a distillation device, carry out distillation under the protection of high-purity inert gas, and collect fractions at 102-105°C; wherein, the inert gas is nitrogen or argon, and the gas flow rate is 60-100°C. 100mL / min.

[0024] S2: Put the fraction in a three-necked flask equipped with a cracking column, a condenser and a receiving device, pass in an inert gas, raise the temperature to 400-420°C at a rate of 1-2°C / min and keep it warm for 24-30h, then cool naturally to room temperature, Take it out to get silane oligomers. Wherein, the inert gas is nitrogen or argon, and the gas flow rate is 150-200 mL / min.

[0025] S3: Dissolve the silane oligomer in xylene, place in a fume hood and stir evenly to obtain the first mixed solution; add propargyl phenolic aldehyde (PN)...

Embodiment 1

[0029] This embodiment provides a method for preparing polycarbosilane with high molecular weight and high linearity, comprising the following steps:

[0030] S1: Put polydimethylsilane (PDMS) in a distillation apparatus, carry out distillation under the protection of high-purity nitrogen, and collect fractions at 102°C; wherein, the flow rate of nitrogen is 60mL / min.

[0031] S2: Put the distillate in a three-necked flask equipped with a cracking column, a condenser and a receiving device, feed nitrogen, raise the temperature to 420°C at a rate of 2°C / min and keep it warm for 24 hours, cool it down to room temperature naturally, and take it out to obtain a silane oligomer . Wherein, the nitrogen flow rate is 200mL / min.

[0032] S3: Dissolve the silane oligomer in xylene, place in a fume hood and stir evenly to obtain the first mixed solution; add propargyl phenolic aldehyde (PN) and divinylbenzene (DVB) to the first mixed solution, heat Keep warm at 80°C and stir until most...

Embodiment 2

[0036] This embodiment provides a method for preparing polycarbosilane with high molecular weight and high linearity, comprising the following steps:

[0037] S1: Put polydimethylsilane (PDMS) in a distillation apparatus, carry out distillation under the protection of high-purity argon, and collect fractions at 105°C; wherein, the flow rate of argon is 80mL / min.

[0038] S2: Put the distillate in a three-neck flask equipped with a cracking column, a condenser and a receiving device, pass in argon gas, raise the temperature to 420°C at a rate of 2°C / min and keep it warm for 28h, cool it down to room temperature naturally, and take it out to obtain silane oligomerization things. Wherein, the inert gas is nitrogen or argon, and the gas flow rate is 150 mL / min.

[0039] S3: Dissolve the silane oligomer in xylene, place in a fume hood and stir evenly to obtain the first mixed solution; add propargyl phenolic aldehyde (PN) and divinylbenzene (DVB) to the first mixed solution, heat ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to a polycarbosilane with high molecular weight and high linearity, a preparation method and application thereof. The preparation method includes: S1: distill polydimethylsilane, collect fractions at 102-105°C; S2: decompose fractions to obtain silane oligomers; S3: dissolve silane oligomers in xylene, stir evenly, and then Add propargyl phenolic novolac and divinylbenzene, heat and stir to obtain a mixed solution; S4: crack the mixed solution, and then purify to obtain the final product. Adopting the technical scheme provided by the present invention, using polydimethylsilane (PDMS) as the main raw material, mixing silane oligomer, a low-temperature decomposition product of PDMS, with DVB and PN, heating carbon-carbon double bonds and silicon-hydrogen bonds to undergo hydrosilylation reactions, Form linear benzene ring-containing oligomers; reheat and polycondensate to form high molecular weight, high linear polycarbosilane; the product has a large molecular weight and high softening point; the degree of branching is small, and the spinnability is good. It is an ideal precursor for the preparation of SiC fibers body.

Description

technical field [0001] The invention relates to the technical field of preparing silicon carbide ceramics, in particular to a polycarbosilane with high molecular weight and high linearity, a preparation method and application thereof. Background technique [0002] Based on its ultra-high strength and modulus, as well as good high temperature resistance and ablation resistance, silicon carbide (SiC) fibers have shown great application prospects in high-tech fields such as aerospace, rocket missiles and weaponry. At the same time, the preparation of silicon carbide fibers has always been a key topic of concern to scholars at home and abroad. Among them, the preparation of precursors is one of the most widely used and most mature methods. Precursor conversion method is an important method for preparing silicon carbide fibers, and the performance of precursors has a crucial influence on the performance of silicon carbide fibers. [0003] In recent years, polycarbosilane (PCS) i...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): C08G77/60D01F9/10
Inventor 吴宝林侯振华
Owner 江西信达航科新材料科技有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap