Novel acetylene‐terminated polyisoimides with excellent processability and properties comparison with corresponding polyimides

Heng, Zhou; Liu, Feng; Zhang, Yongsheng; Fan, Weiyu; Liu, Jingfeng; Wang, Zhen; Zhao, Tong

doi:10.1002/app.34718

Cited by 17 publications

(11 citation statements)

References 46 publications

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“…Typical examples of such networks are epoxy (EP) resin, phenolic resin, cyanate ester (CE) resin and unsaturated polyester resin. These materials are widely used in the construction industry [9], the chemical engineering [10], the electronic industry [11], and the aerospace industry [12]. However, the most prominent disadvantage of the thermosetting resin is its brittleness after curing, which limits its use in certain areas.…”

Section: Introductionmentioning

confidence: 99%

Study on the Relationships between Microscopic Cross-Linked Network Structure and Properties of Cyanate Ester Self-Reinforced Composites

Cao

Liu

et al. 2019

Polymers

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Bisphenol A dicyanate (BADCy) resin microparticles were prepared by precipitation polymerization synthesis and were homogeneously dispersed in a BADCy prepolymer matrix to prepare a BADCy self-reinforced composites. The active functional groups of the BADCy resin microparticles were characterized by Fourier transform infrared (FT-IR) spectroscopy. The results of an FT-IR curve showed that the BADCy resin microparticles had a triazine ring functional group and also had an active reactive group -OCN, which can initiate a reaction with the matrix. The structure of the BADCy resin microparticles was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). From the TEM results, the BADCy resin microparticles dispersed in the solvent were nano-sized and distributed at 40–60 nm. However, from the SEM results, agglomeration occurred after drying, the BADCy resin particels were micron-sized and distributed between 0.3 μm and 0.6 μm. The BADCy resin prepolymer was synthesized in our laboratory. A BADCy self-reinforced composite was prepared by using BADCy resin microparticles as a reinforcement phase. This corresponds to a composite in which the matrix and reinforcement phase are made from different morphologies of the same monomer. The DSC curve showed that the heat flow of the microparticles is different from the matrix during the curing reaction, this means the cured materials should be a microscopic two-phase structure. The added BADCy resin microparticles as reaction sites induced the formation of a more complete and regular cured polymer structure, optimizing the cross-linked network as well as increasing the interplay between the BADCy resin microparticles and prepolymer matrix. Relative to the neat BADCy resin material, the tensile strength, flexural strength, compressive strength and impact strength increased by 98.1%, 40.2%, 27.4%, and 85.4%, respectively. A particle toughening mechanism can be used to explain the improvement of toughness. The reduction in the dielectric constant showed that the cross-linked network of the self-reinforced composite was more symmetrical and less polar than the neat resin material, which supports the enhanced mechanical properties of the self-reinforced composite. In addition, the thermal behavior of the self-reinforced composite was characterized by thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). The results of DMTA also establishes a basis for enhancing mechanical properties of the self-reinforced composite.

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Section: Introductionmentioning

confidence: 99%

Study on the Relationships between Microscopic Cross-Linked Network Structure and Properties of Cyanate Ester Self-Reinforced Composites

Cao

Liu

et al. 2019

Polymers

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“…polyimides from isomeric dianhydride). [14][15][16] Some of these modifications may also exhibit beneficial effects on improving the melt processability of imide oligomers.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and properties of acetylene-terminated isoimide and imide oligomers exhibiting excellent solubility behaviors in low boiling point solvents

Xiang²,

Liu³

et al. 2017

High Performance Polymers

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A series of acetylene-terminated isoimide and imide oligomers were prepared based on 2,3,3 0 ,4 0-biphenyltetracarboxylic dianhydride, 4,4 0-(hexafluoroisopropylidene)diphthalic anhydride, 3,4 0-oxydianiline, and 1,3-bis(3-aminophenoxy)benzene as monomers. 3-Ethynylaniline was used as an end-capping reagent and trifluoroacetic anhydride served as a dehydrating agent. The main oligomer structures were confirmed by Fourier transform infrared spectroscopy, and the thermal imidization was characterized by differential scanning calorimetry. All uncured isoimide and imide oligomers exhibit excellent solubility characteristics in organic solvents such as N,N-dimethylacetamide and N-methyl-2-pyrrolidone, and most of the oligomers can be dissolved in low boiling point solvents such as acetone and ethyl acetate (more than 45 wt%). In comparison with imide analogs, the isoimide oligomers exhibited an increased solubility in low boiling point solvents which can be attributed to their unique asymmetric structures. The properties of the cured films and adhesives were evaluated by dynamic mechanical thermal analysis, thermogravimetric analysis, as well as tensile shear strength tests of the polymer adhesives. The cured films exhibited extremely high glass transition temperatures (T g) of up to 341.6 C and 5% weight loss temperatures (T d5) of up to 518.2 C in a nitrogen atmosphere. Taken in concert, the results obtained indicate that all cured films featured an excellent thermal stability and a particularly high thermal-oxidative stability. One of these oligomers was selected and formulated to form a thermosetting adhesive for further investigation of the adhesion properties. This was done in an effort to improve the high-temperature performance characteristics of composite materials.

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“…Polyimides (PIs) have been widely used in industrial applications, such as automobiles, aircraft parts, electronic packages, films, adhesives, and matrix materials because of their outstanding comprehensive properties. 1 –4 The most widespread route for preparing PIs is two-stage polycondensation with a dianhydride and a diamine in an aprotic amine-based solvent, such as N , N -dimethylacetamide (DMAc), N -methylpyrrolidone, or N , N -dimethylformamide (DMF). 5 –7 However, aprotic polar solvents generally have a high boiling point and can form complex molecules with PI.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization, and properties of thermoplastic polyimides derived from 4,4’-(hexafluoroisopropylidene)diphthalic anhydride in diethylene glycol dimethyl ether

Zhu

Liu

et al. 2017

High Performance Polymers

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By regulating the order of monomer addition, four kinds of copolymer polyimides (PIs) were prepared using diethylene glycol dimethyl ether (DEGDE) and N, N-dimethylacetamide (DMAc) as the solvents. The molecular weights of polyamide acids (PAAs) ranged from 3.8 × 105 to 9.2 × 105. All of the films displayed high glass transition temperatures ( Tgs) ranging from 313°C to 346°C. The polymer films show excellent thermal stabilities with 5% weight loss at temperatures of 505–524°C and char yields at 800°C were as high as 55% under nitrogen. The peel strengths of flexible copper (Cu) clads were in the range from 0.337 N cm−1 to 0.598 N cm−1. Compared to the molecular weight and peel strength of fresh PAA, those of PAAs prepared using DMAc significantly decreased after storage for 3 months at 0°C. However, when DEGDE was used as the solvent, the molecular weights of the PAAs and the thermal properties of the PIs were maintained after long storage time.

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Novel acetylene‐terminated polyisoimides with excellent processability and properties comparison with corresponding polyimides

Cited by 17 publications

References 46 publications

Study on the Relationships between Microscopic Cross-Linked Network Structure and Properties of Cyanate Ester Self-Reinforced Composites

Study on the Relationships between Microscopic Cross-Linked Network Structure and Properties of Cyanate Ester Self-Reinforced Composites

Synthesis and properties of acetylene-terminated isoimide and imide oligomers exhibiting excellent solubility behaviors in low boiling point solvents

Synthesis, characterization, and properties of thermoplastic polyimides derived from 4,4’-(hexafluoroisopropylidene)diphthalic anhydride in diethylene glycol dimethyl ether

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