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The double Phthalonitrile curing reaction process and its composites research

Author: DuRongHua
Tutor: LiuXiaoBo
School: University of Electronic Science and Technology
Course: Applied Chemistry
Keywords: Dual phthalonitrile Aryl ether nitrile segment Model oligomer Composites High temperature
CLC: TQ320.1
Type: Master's thesis
Year: 2010
Downloads: 84
Quote: 1
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Abstract

Bis-phthalonitrile resins are a class of high-performance thermosetting resins, and their excellent thermal stability, thermal oxidative stability, and chemical stability, flame resistance, moisture resistance, and good workability of its aerospace and other high-tech The field has a broad application prospects, its polymerization mechanism and the development of the new dual phthalonitrile resin and optimize the molding process, to improve the workability to obtain a high-performance, high-temperature composite material is of great significance. First, by controlling the model compound prepared by the reaction of the biphenyl type diphthalic terephthalic nitrile (BPH) and cuprous chloride, a model oligomer. Structural characterization results show that the feed ratio and reaction conditions herein control method can effectively double o-phenylenediamine phthalonitrile hyperbranched process from the polymerization process was spun off, and a separate study. Model oligomer core of the phthalocyanine ring is formed relatively quickly, branched phthalocyanine ring formation more slowly, and therefore, during the preparation of the bis phthalonitrile polymers, the early short period of preconditioning and the latter part of the long-term heating treatment are necessary. The model oligomer solution was subjected to long-term placement aggregation occurs, studies show that the agglomerates are composed by many of the lamellar structure is wrapped into a rod structure. Cohesion occurred model oligomer reunion is its structure containing the phthalocyanine ring and the benzene ring structure of the π-π conjugate action. Secondly, the paper as raw material 4, 4'-dihydroxy-biphenyl-2, 6 - dichlorobenzonitrile and 4 - nitro-o-benzene dicarbonitrile and synthesized by a solution reaction, an aryl ether nitrile-containing segment associated benzenoid diphthalic phthalonitrile (2PEN-BPh) and characterization of its structure and the liquid crystal behavior of the liquid crystal phase of the schlieren like nematic texture. Cured with a crosslinking agent, 2, 6 - di-4 - aminophenoxy benzonitrile (BDB) added can effectively reduce the curing reaction temperature, improve the curing reaction speed, to improve its workability. BDB content of 5wt%, and its processing temperature window up to 143oC, and have been greatly improved compared BPh. With the increase in the curing temperature and curing time, the increase in thermal stability and thermal oxidative stability. With the heat treatment, increasing the extent of the reaction. Temperature when the 2PEN-BPh polymer decomposition in nitrogen 5% to 551.00 oC, 800 oC, the char yield up to 78.43%; decomposition temperature of 549.30 oC 5% air atmosphere, the char yield of 600 oC to 88.74%. 2PEN-BPh polymer is very excellent in high-temperature materials. Finally, according to the findings of the polymerization mechanism and 2PEN-BPh reactive, respectively, by thermocompression molding process 2PEN-BPh 2PEN-BAPh (bisphenol A type), as a matrix resin to prepare a fiberglass composite. The experimental results show that the post 2PEN-BAPh / fiberglass composite handle bending strength up to 711.60MPa, the bending modulus reached 32.38GPa, excellent mechanical properties; bending strength and modulus dropped significantly after high temperature treatment, heat and oxygen poor stability. The 2PEN-BPh / fiberglass composite material post-treated bending strength of 479.07MPa, flexural modulus was 16.23GPa, after high temperature treatment, the bending strength is still 422.84 MPa, and flexural modulus 13.80GPa not only good mechanical properties, high temperature The performance is also excellent. Two glass fiber composites have excellent resistance to heat performance and corrosion resistance.

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