Polyethylene glycol: An effective agent for isocyanate-based polyimide foams with enhanced foaming behavior and flexibility

Tian, Huafeng; Yao, Yuanyuan; Li, Weilin; Wang, Kai; Fu, Liwei

doi:10.1177/0954008318801906

Cited by 14 publications

(8 citation statements)

References 29 publications

(41 reference statements)

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“…The addition of graphene oxide (GO) nanosheets improved the foaming rate of PI reducing the product density by 50% to 0.075 g/cm 3 and increased the bending strength by 22.5%. Tian et al 31 mixed polyethylene glycol (as chain extender) with alcoholylated 1,2,4,5‐pyromellitic dianhydride (PMDA) and polymerized them with isocyanate. A series of PI foams were prepared by foaming and imidization.…”

Section: Introductionmentioning

confidence: 99%

Effect ofDAPBOsegment on the structure and performance enhancement of powder foamedBTDA‐ODApolyimide

Liu

Liang

et al. 2020

J of Applied Polymer Sci

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Achieving excellent thermal stability, good mechanical strength, and low-density in one product, is a big challenge in the design and synthesis of polyimide (PI) foams. We selected a rigid diamine monomer, 2-(4-aminophenyl)-5-aminobenzoxazole (DAPBO) to partially replace 4,4 0-oxydianiline (ODA) in BTDA-ODA system, and studied the effect on properties of foamed PI products. With various molar ratio between DABPO and ODA (0:5, 1:4, 2:3, 3:2, 4:1, 5:0), the diamine(s) polymerized with 3,3 0 ,4,4 0-benzophenonetetracarboxylic dianhydride (BTDA) and produced six PI precursors (PAE-0~PAE-5). After foaming and thermal imidization, corresponding PI foams (PI-0~PI-5) prepared. Among them, PI-3 has a glass transition temperature of 386 C, which is 95 C higher than PI-0, and its compressive strength reaches 1.32 MPa. Moreover, PI-3 has a uniform cell structure with an average pore size of~200 μm. The analysis results show that PI-3 is in a transition state from amorphous to partial crystalline, maintaining a balance between flexibility and rigidity. The addition of DABPO not only increases the rigidity of polymer molecular segments, but also introduces N and O atoms that can form intermolecular hydrogen bonds between molecules, which increases the packing density and arrangement regularity of polymer molecules. K E Y W O R D S DABPO, enhanced thermal stability, high mechanical strength, polyimide foam, powder foaming 1 | INTRODUCTION Foam plastic is a plastic with a large number of micropores manufactured by a foaming process. 1,2 Compared with ordinary plastics, it has lower density, smaller thermal conductivity and higher specific strength. Foam plastic also has the properties of absorbing impact loads, sound absorption, and heat insulation, and is widely used in many fields. 3-6 Polyimide (PI) is a family of polymers with the best overall evaluation among engineering plastics, possessing good thermal stability, insulation, and mechanical properties. 7-12 Monsanto and DuPont conducted the earliest research on PI foam in 1960s. 13 Subsequently, National Aeronautics and Space Administration (NASA) Langley Research Center and Unitika America collaborated on the research of PI foams and promote their commercialization. After foaming, the density of PI can be reduced by more than 90%, meanwhile its glass transition temperature (T g) increases, and thermal conductivity decreases significantly. 14-19 The reduction of weight and increase of strength are the eternal theme of material development, especially in

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Section: Introductionmentioning

confidence: 99%

Effect ofDAPBOsegment on the structure and performance enhancement of powder foamedBTDA‐ODApolyimide

Liu

Liang

et al. 2020

J of Applied Polymer Sci

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“…Foams prepared under acid catalysis favored predominantly the formation of ether linkages between phenolic compounds and the long molecular chains of PEG 400 rather than the aromatic chains. This could give more flexibility between the macromolecular segments, leading to an increased expanding ability during the foaming process and resulting in lower densities of the A-BPF foams . In contrast, B-BPF foams promoted the formation of a more dense structure (high content of aromatic groups via autocondensation reaction).…”

Section: Results and Discussionmentioning

confidence: 99%

Effect of Catalysts and Curing Temperature on the Properties of Biosourced Phenolic Foams

Issaoui

Hoyos-Martínez

Pellerin

et al. 2021

ACS Sustainable Chem. Eng.

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Biosourced phenolic foams (BPFs) based on lignin alkaline liquor and tannins were successfully synthesized without using formaldehyde and any blowing agent. The influence of three sorts of catalysis (acid, alkaline, and thermal) and different curing temperatures (80, 100, and 120 °C) on the final properties of the foams was investigated. Concerning foam morphology, scanning electron microscopy observations showed that a low-curing temperature could significantly reduce the cell size and improve the structural homogeneity of phenolic foams. It was also proved by Fourier transform infrared spectroscopy analysis that alkaline catalysis promotes aromatic functions, whereas the polycondensation reaction and ether linkages were dominant under acid catalysis. Thermogravimetric analysis, cone calorimetry, and Bunsen burner test revealed that the foams prepared under alkaline catalysis displayed the best thermal stability and fire resistance. The obtained BPFs exhibited a high compressive strength (0.11−1.65 MPa) and good thermal conductivity (41.5−50.55 mW/m•K), which are linearly proportional to the foam densities. Accordingly, they could be used as a thermal insulator for the construction or retrofitting of buildings.

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“…This modified PIF shows excellent mechanical properties compared with previous reports. 7,12,24 The amino group grafted on the surface of HGM can be connected with the polyimide matrix by chemical and hydrogen bonds. Thus, the interfacial compatibility between HGM and PIF was effectively improved to enhance the performance in PIF.…”

Section: Mechanical Propertymentioning

confidence: 99%

“…Many researchers have reported the effects of catalyst, cross-linking agent, slurry temperature, and refilled aromatic dianhydride on the morphology and properties of isocyanate-based PIF. 7–11 The results show that suitable catalyst, cross-linking agent, and foaming conditions are necessary to prepare PIF with low density, outstanding morphology, and high thermal stability. However, the poor mechanical properties and thermal insulation of PIF hinder its industrial application.…”

Section: Introductionmentioning

confidence: 99%

Modified hollow glass microsphere isocyanate-based polyimide foam composite with improved mechanical and thermal insulation properties

Liu

Fu-xing

et al. 2022

High Performance Polymers

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In this work, hollow glass microspheres (HGM) were introduced into the polyimide matrix as an effective reinforcement filler to improve the mechanical and thermal insulation properties of the polyimide foams (PIF). The HGM was surface-modified with the silane coupling agent to enhance the interfacial compatibility with PIF. Experimental results revealed that the average cellular diameter of PIF decreased obviously with the addition of the modified HGM (M-HGM). The apparent density of foams also increased from 15.85 to 18.34 kg/m3 when the M-HGM combination was changed from 0 to 12 percent (wt.%). Compared with the pure PIF, the composite foams added 8 wt.% M-HGM showed high compression strength (65 kPa) and compression modulus (1147 kPa), resulting in a distinct enhancement in mechanical properties. Furthermore, the addition of M-HGM filler also improved the thermal insulation performance of PIF, which exhibited the minimum thermal conductivity of 29.48 mW·m−1·K−1 with 8 wt.% M-HGM. Thus, considering the improved mechanical and insulation properties of the prepared PIF, it could be a promising candidate for the high temperature-resistant thermal insulating applications.

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Polyethylene glycol: An effective agent for isocyanate-based polyimide foams with enhanced foaming behavior and flexibility

Cited by 14 publications

References 29 publications

Effect ofDAPBOsegment on the structure and performance enhancement of powder foamedBTDA‐ODApolyimide

Effect ofDAPBOsegment on the structure and performance enhancement of powder foamedBTDA‐ODApolyimide

Effect of Catalysts and Curing Temperature on the Properties of Biosourced Phenolic Foams

Modified hollow glass microsphere isocyanate-based polyimide foam composite with improved mechanical and thermal insulation properties

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