Copolymers and interpenetrating polymer networks of thermoreactive nitrogen-containing resins. Mini review

2020 ◽  
Vol 42 (4) ◽  
pp. 245-253
Author(s):  
A.M. Fainleib ◽  

In a short review the effective methods of optimization of structure and properties of high-performance polymers obtained from thermoreactive nitrogen-containing resins such as benzoxazines, bismaleimides, cyanate esters have been analysed. High crosslinked density copolymer thermosets are synthesized through chemical interactions between reactive functional groups, which belong to the monomers/oligomers used. The different possible processes such as copolymerization or formation of interpenetrating polymer networks are discussed. The high-performance polymers and composites from thermoreactive nitrogen-containing resins are effectively used in aerospace industry and microelectronics as materials possessing high thermal and thermooxidative stability, radiation and chemical resistance, low water absorption, low dielectric loss, high dimension stability and high adhesion to different substrate. The performance characteristics of this kind of materials can be controlled by changing their composition, temperature-time curing schedule, using catalytic systems. Keywords: copolymers, IPNs, thermoreactive resins, benzoxazine, bismaleimide, cyanate ester resins.

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 862 ◽  
Author(s):  
Jingfeng Liu ◽  
Weifeng Fan ◽  
Gewu Lu ◽  
Defeng Zhou ◽  
Zhen Wang ◽  
...  

Thermoplastic polyimide (TPI) was synthesized via a traditional one-step method using 2,3,3′,4′-biphenyltetracarboxylic dianhydride (3,4′-BPDA), 4,4′-oxydianiline (4,4′-ODA), and 2,2′-bis(trifluoromethyl)benzidine (TFMB) as the monomers. A series of semi-interpenetrating polymer networks (semi-IPNs) were produced by dissolving TPI in bisphenol A dicyanate (BADCy), followed by curing at elevated temperatures. The curing reactions of BADCy were accelerated by TPI in the blends, reflected by lower curing temperatures and shorter gelation time determined by differential scanning calorimetry (DSC) and rheological measurements. As evidenced by scanning electron microscopy (SEM) images, phase separation occurred and continuous TPI phases were formed in semi-IPNs with a TPI content of 15% and 20%. The properties of semi-IPNs were systematically investigated according to their glass transition temperatures (Tg), thermo-oxidative stability, and dielectric and mechanical properties. The results revealed that these semi-IPNs possessed improved mechanical and dielectric properties compared with pure polycyanurate. Notably, the impact strength of semi-IPNs was 47%–320% greater than that of polycyanurate. Meanwhile, semi-IPNs maintained comparable or even slightly higher thermal resistance in comparison with polycyanurate. The favorable processability and material properties make TPI/BADCy blends promising matrix resins for high-performance composites and adhesives.


2011 ◽  
Vol 236-238 ◽  
pp. 2679-2682 ◽  
Author(s):  
Hua Xu ◽  
Qian Ning ◽  
Da Hu Yao ◽  
Yu Xin He ◽  
Yu Qing Zhang

Novel interpenetrating polymer networks (IPNs) of Polydicyclopentadiene/Polystyrene (PDCPD/PS) were prepared by in-situ polymerization using Ziegler-Natta and peroxide as double catalytic systems. The structure of PDCPD/PS alloy was characterized by Soxhlet extraction, infrared spectrum (IR) and scanning electron microscope (SEM). The results showed that the polymerization of dicyclopentadiene (DCPD) was facilitated in the presence of styrene and the rate of polymerization as well as the conversion of PDCPD was improved with styrene content. The strong IR absorption peaks of PS indicated high penetration of PS within PDCPD networks, and in the process forming IPNs. There were no obvious traces of PS in the alloy brittle fracture, which prepared in liquid nitrogen and was etched by toluene. This result also demonstrated that PS was dispersed in molecular level in the polymer alloy networks and it tangled with PDCPD. The measurements mechanical properties showed that the tensile strength of the polymer alloy was improved with styrene content. This may be due to homogeneous dispersion of PS in the IPNs. The synergistic effect of PS and PDCPD also played a part in enhancing the mechanical properties of polymer alloy.


2016 ◽  
Vol 23 (6) ◽  
pp. 579-588
Author(s):  
Zhiran Chen ◽  
Yajie Lei ◽  
Hailong Tang ◽  
Xiaobo Liu

AbstractThe 2,2-bis[4-(3,4)-dicyanophenoxy phenyl]propane (BAPh)/polyarylene ether nitrile (PEN-OH) prepolymers and polymers were prepared by heat polymerization. Firstly, BAPh/PEN-OH systems were characterized using differential scanning calorimetry, dynamic rheological analysis, and thermal gravimetric analysis. The results revealed that the polymerization reaction can be controlled by various concentrations of PEN-OH and postcuring temperatures, and BAPh/PEN-OH prepolymers had low curing temperatures (229.3–300.4°C), large processing windows (∼106.5°C) with low melt viscosities, and excellent thermal stabilities. Then, the polymerization reaction and surface structures of BAPh/PEN-OH systems were investigated using Fourier transform infrared and scanning electron microscopy, respectively. The interpenetrating polymer networks were found in BAPh/PEN-OH polymers, suggesting that the addition of PEN-OH can not only promote the curing behaviors of BAPh but also increase the toughness of the polymers. The flexure strength and modulus of BAPh/PEN-OH polymers increased with the introduction of PEN-OH. The dielectric properties of BAPh/PEN-OH polymers were investigated, which had little dependence on the frequency. BAPh/PEN-OH systems can be used as a good candidate for high-performance polymeric materials.


Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3489
Author(s):  
Yashu He ◽  
Jingting Wang ◽  
Igor S. Sirotin ◽  
Vyacheslav V. Kireev ◽  
Jianxin Mu

This study reports on a series of crosslinked poly(arylene ether)s with POSS in the main chain. The fluorinated and terminated poly(arylene ether)s were first synthesized by the nucleophilic reaction of diphenol POSS and decafluorodiphenyl monomers, including decafluorobiphenyl, decaflurobenzophenone, and decafluorodiphenyl sulfone. They were then reacted with 3-hydroxyphenyl acetylene to produce phenylacetylene-terminated poly(arylene ether)s. The polymers were of excellent processability. When heated to a high temperature, the polymers converted into a crosslinked network, exhibiting a low range of dielectric constant from 2.17 to 2.58 at 1 HMz, strong resistance against chemical solutions, low dielectric losses, and good thermal and hydrophobic properties.


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