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Methylethynyl-Terminated Polyimide Nanofibrous Membranes: High-Temperature-Resistant Adhesives with Low-Temperature Processability. Polymers (Basel) 2022; 14:polym14194078. [PMID: 36236026 PMCID: PMC9571861 DOI: 10.3390/polym14194078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/21/2022] [Accepted: 09/24/2022] [Indexed: 11/17/2022] Open
Abstract
As an alternative to traditional riveting and welding materials, high-temperature-resistant adhesives, with their unique advantages, have been widely used in aviation, aerospace, and other fields. Among them, polyimide (PI) adhesives have been one of the most studied species both from basic and practical application aspects. However, in the main applications of solvent-type PI adhesives, pinholes or bubbles often exist in the cured PI adhesive layers due to the solvent volatilization and dehydration reaction, which directly affect the adhesive performance. To address this issue, electrospun PI nanofibrous membranes (NFMs) were employed as solvent-free or solvent-less adhesives for stainless steel in the current work. To enhance the adhesion of PI adhesives to the metal substrates, phenolphthalein groups and flexible ether bonds were introduced into the main chain of PIs via the monomers of 4,4′-oxydiphthalic anhydride (ODPA) and 3,3-bis[4-(4-aminophenoxy)phenyl] phthalide (BAPPT). At the same time, the methylethynyl group was used as the end-capping component, and the crosslinking reaction of the alkynyl group at high temperature further increased the adhesive strength of the PI adhesives. Three kinds of methylethynyl-terminated PI (METI) NFMs with the set molecular weights of 5000, 10,000, and 20,000 g/mol were first prepared via the one-step high-temperature polycondensation procedure. Then, the PI NFMs were fabricated via the standard electrospinning procedure from the soluble METI solutions. The afforded METI NFMs showed excellent melt-flowing behaviors at high temperature. Incorporation of the methylethynyl end-capping achieved a crosslinking reaction at 280−310 °C for the NFMs, which was about 70 °C lower than those of the phenylacetylene end-capping counterparts. Using the METI NFMs as adhesive, stainless steel adherends were successfully bonded, and the single-lap shear strength (LSS) was higher than 20.0 MPa at both room temperature (25 °C) and high temperature (200 °C).
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Pan Z, Wang HL, Qi HR, Gao YS, Wang XL, Zhi XX, Zhang Y, Ren X, Liu JG. Molecular Design, Preparation, and Characterization of Fluoro-Containing Polyimide Ultrafine Fibrous Membranes with High Whiteness, High Thermal Stability, and Good Hydrophobicity. Molecules 2022; 27:molecules27175447. [PMID: 36080211 PMCID: PMC9457758 DOI: 10.3390/molecules27175447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/21/2022] [Accepted: 08/23/2022] [Indexed: 11/16/2022] Open
Abstract
Polymeric ultrafine fibrous membranes (UFMs) with high thermal stability and high whiteness are highly desired in modern optoelectronic applications. A series of fluoro-containing polyimide (FPI) UFMs with high whiteness, good thermal stability, and good hydrophobicity were prepared via a one-step electrospinning procedure from the organo-soluble FPI resins derived from a fluoro-containing dianhydride, 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA), and various diamines containing either pendant trifluoromethyl (–CF3) groups or alicyclic units in the side chains. The obtained FPI UFMs, including FPI-1 from 6FDA and 3,5-diaminobenzotrifluoride (TFMDA), FPI-2 from 6FDA and 2′-trifluoromethyl-3,4′-oxydianiline (3FODA), FPI-3 from 6FDA and 1,4-bis[(4-amino-2-trifluoromethyl)phenoxy]benzene (6FAPB), FPI-4 from 4,4′-bis[(4-amino-2-trifluoromethyl)phenoxy]biphenyl (6FBAB), and FPI-5 from 6FDA and 4’-tert-butyl-cyclohexyl-3,5-diaminobenzoate (DABC) showed whiteness indices (WI) higher than 87.00 and optical reflectance values higher than 80% at the wavelength of 457 nm (R457), respectively. The FPI-5 UFM, especially, showed the highest WI of 92.88. Meanwhile, the prepared PI UFMs exhibited good hydrophobic features with water contact angles (WCA) higher than 105°. At last, the PI UFMs exhibited good thermal stability with glass transition temperatures (Tg) higher than 255 °C, and the 5% weight-loss temperatures (T5%) higher than 510 °C in nitrogen.
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Affiliation(s)
- Zhen Pan
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China
| | - Han-li Wang
- Shandong Huaxia Shenzhou New Material Co., Ltd., Zibo 256401, China
| | - Hao-ran Qi
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China
| | - Yan-shuang Gao
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China
| | - Xiao-lei Wang
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China
| | - Xin-xin Zhi
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China
| | - Yan Zhang
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China
| | - Xi Ren
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China
| | - Jin-gang Liu
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China
- Correspondence: ; Tel.: +86-10-8232-2972
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Feng J, Wang Y, Qin X, Lv Y, Huang Y, Yang Q, Li G, Kong M. Property Evolution and Molecular mechanisms of Aluminized Colorless Transparent Polyimide under Space Ultraviolet Irradiation. Polym Degrad Stab 2022. [DOI: 10.1016/j.polymdegradstab.2022.109915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Electrospun Semi-Alicyclic Polyimide Nanofibrous Membrane: High-Reflectance and High-Whiteness with Superior Thermal and Ultraviolet Radiation Stability for Potential Applications in High-Power UV-LEDs. NANOMATERIALS 2021; 11:nano11081977. [PMID: 34443808 PMCID: PMC8399263 DOI: 10.3390/nano11081977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 02/05/2023]
Abstract
Polymeric nanofibrous membranes (NFMs) with both high whiteness and high thermal and ultraviolet (UV) stability are highly desired as reflectors for ultraviolet light-emitting diodes (UV-LEDs) devices. In the current work, a semi-alicyclic and fluoro-containing polyimide (PI) NFM with potential application in such kinds of circumstances was successfully fabricated from the organo-soluble PI resin solution via a one-step electrospinning procedure. In order to achieve the target, a semi-alicyclic PI resin was first designed and synthesized from an alicyclic dianhydride, 3,4-dicarboxy-1,2,3,4,5,6,7,8-decahydro-1-naphthalenesuccinic dianhydride (or hydrogenated tetralin dianhydride, HTDA), and a fluoro-containing diamine, 2,2-bis[4-(4-amino-phenoxy)phenyl]hexafluoropropane (BDAF), via an imidization procedure. The derived PI (HTDA-BDAF) resin possessed a number-average molecular weight (Mn) higher than 33,000 g/mol and was highly soluble in polar aprotic solvents, such as N,N-dimethylacetamide (DMAc). The electrospinning solution was prepared by dissolving the PI resin in DMAc at a solid content of 25–35 wt%. For comparison, the conventional high-whiteness polystyrene (PS) NFM was prepared according to a similar electrospinning procedure. The thermal and UV stability of the derived PI and PS NFMs were investigated by exposure under the UV-LED (wavelength: 365 nm) irradiation. Various thermal evaluation results indicated that the developed PI (HTDA-BDAF) NFM could maintain both the high reflectance and high whiteness at elevated temperatures. For example, after thermal treatment at 200 °C for 1 h in air, the PI (HTDA-BDAF) NFM exhibited a reflectance at a wavelength of 457 nm (R457) of 89.0%, which was comparable to that of the pristine PI NMF (R457 = 90.2%). The PI (HTDA-BDAF) NFM exhibited a whiteness index (WI) of 90.88, which was also close to that of the pristine sample (WI = 91.22). However, for the PS NFM counterpart, the R457 value decreased from the pristine 88.4% to 18.1% after thermal treatment at 150 °C for 1 h, and the sample became transparent. The PI NFM maintained good optical and mechanical properties during the high dose (2670 J/cm2) of UV exposure, while the properties of the PS NFM apparently deteriorated under the same UV aging.
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Qi HR, Shen DX, Jia YJ, An YC, Wu H, Wei XY, Zhang Y, Zhi XX, Liu JG. Preparation and Properties of Electrospun Phenylethynyl-Terminated Polyimide Nano-Fibrous Membranes with Potential Applications as Solvent-Free and High-Temperature Resistant Adhesives for Harsh Environments. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:1525. [PMID: 34207676 PMCID: PMC8227671 DOI: 10.3390/nano11061525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/04/2021] [Accepted: 06/07/2021] [Indexed: 11/16/2022]
Abstract
High-temperature-resistant polymeric adhesives with high servicing temperatures and high adhesion strengths are highly desired in aerospace, aviation, microelectronic and other high-tech areas. The currently used high-temperature resistant polymeric adhesives, such as polyamic acid (PAA), are usually made from the high contents of solvents in the composition, which might cause adhesion failure due to the undesirable voids caused by the evaporation of the solvents. In the current work, electrospun preimidized polyimide (PI) nano-fibrous membranes (NFMs) were proposed to be used as solvent-free or solvent-less adhesives for stainless steel adhesion. In order to enhance the adhesion reliability of the PI NFMs, thermally crosslinkable phenylethynyl end-cappers were incorporated into the PIs derived from 3,3',4,4'-oxydiphthalic anhydride (ODPA) and 3,3-bis[4-(4-aminophenoxy)phenyl]phthalide (BAPPT). The derived phenylethynyl-terminated PETI-10K and PETI-20K with the controlled molecular weights of 10,000 g mol-1 and 20,000 g mol-1, respectively, showed good solubility in polar aprotic solvents, such as N-methyl-2-pyrrolidinone (NMP) and N,N-dimethylacetamide (DMAc). The PI NFMs were successfully fabricated by electrospinning with the PETI/DMAc solutions. The ultrafine PETI NFMs showed the average fiber diameters (dav) of 627 nm for PETI-10K 695 nm for PETI-20K, respectively. The PETI NFMs showed good thermal resistance, which is reflected in the glass transition temperatures (Tgs) above 270 °C. The PETI NFMs exhibited excellent thermoplasticity at elevated temperatures. The stainless steel adherends were successfully adhered using the PETI NFMs as the adhesives. The PI NFMs provided good adhesion to the stainless steels with the single lap shear strengths (LSS) higher than 20.0 MPa either at room temperature (25 °C) or at an elevated temperature (200 °C).
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Affiliation(s)
- Hao-ran Qi
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-r.Q.); (Y.-j.J.); (Y.-c.A.); (H.W.); (X.-y.W.); (Y.Z.); (X.-x.Z.)
| | - Deng-xiong Shen
- Aerospace Research Institute of Materials& Processing Technology, Beijing 100076, China;
| | - Yan-jiang Jia
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-r.Q.); (Y.-j.J.); (Y.-c.A.); (H.W.); (X.-y.W.); (Y.Z.); (X.-x.Z.)
| | - Yuan-cheng An
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-r.Q.); (Y.-j.J.); (Y.-c.A.); (H.W.); (X.-y.W.); (Y.Z.); (X.-x.Z.)
| | - Hao Wu
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-r.Q.); (Y.-j.J.); (Y.-c.A.); (H.W.); (X.-y.W.); (Y.Z.); (X.-x.Z.)
| | - Xin-ying Wei
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-r.Q.); (Y.-j.J.); (Y.-c.A.); (H.W.); (X.-y.W.); (Y.Z.); (X.-x.Z.)
| | - Yan Zhang
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-r.Q.); (Y.-j.J.); (Y.-c.A.); (H.W.); (X.-y.W.); (Y.Z.); (X.-x.Z.)
| | - Xin-xin Zhi
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-r.Q.); (Y.-j.J.); (Y.-c.A.); (H.W.); (X.-y.W.); (Y.Z.); (X.-x.Z.)
| | - Jin-gang Liu
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-r.Q.); (Y.-j.J.); (Y.-c.A.); (H.W.); (X.-y.W.); (Y.Z.); (X.-x.Z.)
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Huangfu MG, Shen DX, Zhi XX, Zhang Y, Jia YJ, An YC, Wei XY, Liu JG. Preparation and Characterization of Electrospun Fluoro-Containing Poly(imide-benzoxazole) Nano-Fibrous Membranes with Low Dielectric Constants and High Thermal Stability. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:537. [PMID: 33669852 PMCID: PMC7923222 DOI: 10.3390/nano11020537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 11/30/2022]
Abstract
The rapid development of advanced high-frequency mobile communication techniques has advanced urgent requirements for polymer materials with high-temperature resistance and good dielectric properties, including low dielectric constants (low-Dk) and low dielectric dissipation factors (low-Df). The relatively poor dielectric properties of common polymer candidates, such as standard polyimides (PIs) greatly limited their application in high-frequency areas. In the current work, benzoxazole units were successfully incorporated into the molecular structures of the fluoro-containing PIs to afford the poly(imide-benzoxazole) (PIBO) nano-fibrous membranes (NFMs) via electrospinning fabrication. First, the PI NFMs were prepared by the electrospinning procedure from organo-soluble PI resins derived from 2,2'-bis(3,4-dicarboxy-phenyl)hexafluoropropane dianhydride (6FDA) and aromatic diamines containing ortho-hydroxy-substituted benzamide units, including 2,2-bis[3-(4-aminobenzamide)-4-hydroxylphenyl]hexafluoropropane (p6FAHP) and 2,2-bis[3-(3-aminobenzamide)-4-hydroxyphenyl]hexafluoropropane (m6FAHP). Then, the PI NFMs were thermally dehydrated at 350 °C in nitrogen to afford the PIBO NFMs. The average fiber diameters (dav) for the PIBO NFMs were 1225 nm for PIBO-1 derived from PI-1 (6FDA-p6FAHP) precursor and 816 nm for PIBO-2 derived from PI-2 (6FDA-m6FAHP). The derived PIBO NFMs showed good thermal stability with the glass transition temperatures (Tgs) over 310 °C and the 5% weight loss temperatures (T5%) higher than 500 °C in nitrogen. The PIBO NFMs showed low dielectric features with the Dk value of 1.64 for PIBO-1 and 1.82 for PIBO-2 at the frequency of 1 MHz, respectively. The Df values were in the range of 0.010~0.018 for the PIBO NFMs.
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Affiliation(s)
- Meng-Ge Huangfu
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (M.-G.H.); (X.-X.Z.); (Y.Z.); (Y.-J.J.); (Y.-C.A.); (X.-Y.W.)
| | - Deng-Xiong Shen
- Aerospace Research Institute of Materials& Processing Technology, Beijing 100076, China;
| | - Xin-Xin Zhi
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (M.-G.H.); (X.-X.Z.); (Y.Z.); (Y.-J.J.); (Y.-C.A.); (X.-Y.W.)
| | - Yan Zhang
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (M.-G.H.); (X.-X.Z.); (Y.Z.); (Y.-J.J.); (Y.-C.A.); (X.-Y.W.)
| | - Yan-Jiang Jia
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (M.-G.H.); (X.-X.Z.); (Y.Z.); (Y.-J.J.); (Y.-C.A.); (X.-Y.W.)
| | - Yuan-Cheng An
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (M.-G.H.); (X.-X.Z.); (Y.Z.); (Y.-J.J.); (Y.-C.A.); (X.-Y.W.)
| | - Xin-Ying Wei
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (M.-G.H.); (X.-X.Z.); (Y.Z.); (Y.-J.J.); (Y.-C.A.); (X.-Y.W.)
| | - Jin-Gang Liu
- School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (M.-G.H.); (X.-X.Z.); (Y.Z.); (Y.-J.J.); (Y.-C.A.); (X.-Y.W.)
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Zheng Zhu, Xu Y, Ye Z, Yan L, Tao Y, Ma W, Liu J, Jian Chen. Synthesis and Properties of Colorless Transparent Polyimides with Low CTE and High Tensile Strength. POLYMER SCIENCE SERIES B 2020. [DOI: 10.1134/s1560090420330076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Qi L, Liu J, Yang Y, Guo C, Huangfu M, Zhang Y. Solvent‐resistant ultrafine nonwoven fibrous membranes by ultraviolet‐assisted electrospinning of organo‐soluble photosensitive polyimide resin. J Appl Polym Sci 2020. [DOI: 10.1002/app.50048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Lin Qi
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology China University of Geosciences Beijing China
| | - Jin‐gang Liu
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology China University of Geosciences Beijing China
| | - Yang Yang
- Composite Centre Commercial Aircraft Corporation of China, Ltd. Shanghai China
| | - Chen‐yu Guo
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology China University of Geosciences Beijing China
| | - Meng‐ge Huangfu
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology China University of Geosciences Beijing China
| | - Yan Zhang
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology China University of Geosciences Beijing China
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