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Li J, Yu N, Ding Y, Xu T, Zhang G, Jing Z, Shi X. Fabrication of rigid polyimide foams with overall enhancement of thermal and mechanical properties. J CELL PLAST 2020. [DOI: 10.1177/0021955x20956925] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Polyimide (PI) foams have been developed for decades and widely used as thermal insulation materials. However, the limited mechanical and thermal properties continually being a serious problem that restrict their further applications. In this study, a series of rigid PI foams with excellent mechanical and thermal performance were fabricated by the reaction of benzophenone-3,3',4,4'-tetracarboxylic dianhydride (BTDA) with two diamines of 2–(4-aminophenyl)-5-aminobenzimidazole (BIA) and 4,4'-diaminodiphenyl ether (ODA) with various molar ratios, and the cis-5-norbornene-endo-2,3-dicarbox-ylic acid (NA) was introduced as end-capping and foaming agent. The results demonstrate that the foaming degree decreases with increasing the BIA molar ratio in the polymer chains owing to the elevated melt viscosity of precursor. Furthermore, the prepared rigid PI foams exhibit excellent thermal and mechanical properties. When the BIA contend up to 40 mol%, the glass transition temperature ( Tg) and the temperature at 10% of weight loss ( Td 10 %) of PI foam increased ∼80°C and ∼35°C in comparison with the pristine PI-0, respectively. In addition, the compressive strength and modulus at 10% strain of PI-4 reached to 5.48 MPa and 23.8 MPa, respectively. For the above-mentioned advantages, the prepared rigid PI foams are promising candidates as thermal insulation and structure support composite materials in the aerospace and aviation industries.
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Affiliation(s)
- Jianwei Li
- School of Materials Science and Engineering, Xi’an Polytechnic University, Xi’an, China
| | - Ni Yu
- MOE Key Laboratory of Applied Physics and Chemistry in Space, Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi’an, China
| | - Yuanqing Ding
- School of Materials Science and Engineering, Xi’an Polytechnic University, Xi’an, China
| | - Tianle Xu
- School of Materials Science and Engineering, Xi’an Polytechnic University, Xi’an, China
| | - Guangcheng Zhang
- MOE Key Laboratory of Applied Physics and Chemistry in Space, Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi’an, China
| | - Zhanxin Jing
- MOE Key Laboratory of Applied Physics and Chemistry in Space, Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi’an, China
| | - Xuetao Shi
- MOE Key Laboratory of Applied Physics and Chemistry in Space, Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi’an, China
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Azdast T, Hasanzadeh R. Increasing cell density/decreasing cell size to produce microcellular and nanocellular thermoplastic foams: A review. J CELL PLAST 2020. [DOI: 10.1177/0021955x20959301] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Nowadays, polymeric foams have attracted particular attention in scientific and industrial societies due to their unique properties, such as high strength to weight ratio, excellent thermal and sound insulation, and low cost. Researchers have shown that the extraordinary properties of polymeric foams such as superior thermal insulation, can be achieved by increasing the cell density/decreasing the cell size. In this regard, firstly, the most important foaming processes, i.e. batch, extrusion, and injection molding are studied in the present research. Then, cell nucleation stage as the most crucial phenomenon for achieving high cell density/small cell size is investigated in detail. In the next step, the most important researches in the field of polymeric foams are introduced in which the largest cell densities/smallest cell sizes have been achieved. The investigations show that the most remarkable results (highest cell densities/smallest cell sizes) belong to the batch process. Also, the use of nucleating agents, increasing the solubility of blowing agent into the polymer, and the use of nanoparticles are the most efficient solutions to achieve microcellular and nanocellular structures.
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Affiliation(s)
- Taher Azdast
- Department of Mechanical Engineering, Faculty of Engineering, Urmia University, Urmia, Iran
| | - Rezgar Hasanzadeh
- Department of Mechanical Engineering, Faculty of Engineering, Urmia University, Urmia, Iran
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