The Experts below are selected from a list of 4947 Experts worldwide ranked by ideXlab platform
Harold S Burlhis - One of the best experts on this subject based on the ideXlab platform.
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Polyetherimide a new high performance thermoplastic resin
Journal of Polymer Science: Polymer Symposia, 2007Co-Authors: Robert O Johnson, Harold S BurlhisAbstract:A new high-performance amorphous thermoplastic, named Polyetherimide, has been developed by the General Electric Company. This resin is characterized by high deflection temperature (200°C at 264 psi), high tensile strength and flexural modulus (480,000 psi), and very good retention of mechanical properties at elevated temperatures. In addition, the resin exhibits good electrical properties, which remain stable over a wide range of temperature and frequencies (including microwave). Polyetherimide is inherently flame resistant without the use of additives. It has a high limiting oxygen index of 47, combined with NBS smoke chamber results which show the lowest specific optical density of any unfilled thermoplastic (Dmax = 31). One synthetic method for the preparation of Polyetherimides and a comprehensive property profile of the first member of this polymer family are presented.
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Polyetherimide: A new high‐performance thermoplastic resin
Journal of Polymer Science: Polymer Symposia, 2007Co-Authors: Robert O Johnson, Harold S BurlhisAbstract:A new high-performance amorphous thermoplastic, named Polyetherimide, has been developed by the General Electric Company. This resin is characterized by high deflection temperature (200°C at 264 psi), high tensile strength and flexural modulus (480,000 psi), and very good retention of mechanical properties at elevated temperatures. In addition, the resin exhibits good electrical properties, which remain stable over a wide range of temperature and frequencies (including microwave). Polyetherimide is inherently flame resistant without the use of additives. It has a high limiting oxygen index of 47, combined with NBS smoke chamber results which show the lowest specific optical density of any unfilled thermoplastic (Dmax = 31). One synthetic method for the preparation of Polyetherimides and a comprehensive property profile of the first member of this polymer family are presented.
Jiping Xu - One of the best experts on this subject based on the ideXlab platform.
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Structure/Permeability and Permselectivity Relationship of Polyetherimides from 1,4-Bis(3,4-Dicarboxyphenoxy) Benzene Dianhydride. III
Journal of Macromolecular Science Part A, 1997Co-Authors: Yuesheng Li, Mengxian Ding, Jiping XuAbstract:Gas permeability coefficients of a series of aromatic Polyetherimides prepared from 1,4-bis(3,4-dicarboxyphenoxy) benzene dianhydride (HQDPA) and four (methylene dianiline)s with a methyl side group to H 2 , CO 2 , O 2 , N 2 , and CH 4 were measured under 7 atm and within a temperature range from 30 to 150°C. The gas permeabilities and permselectivities of these polymers were compared with those of the HQDPA-based Polyetherimides from methylene dianiline (MDA) and isopropylidene dianiline (IPDA). The number and position of the methyl side groups on the benzene rings of the diamine residues strongly affect the gas permeabilities and permselectivities of the HQDPA-based Polyetherimides. The gas permeability of the Polyetherimide progressively increases with an increase in the number of the methyl side groups. Both the gas permeability and permselectivity of the Polyetherimides with methyl side groups are higher than those of HQDPA-MDA. The Polyetherimide prepared from 3,3'-dimethyl 4,4'-methylene dianiline (DMMDA1) possesses both higher permeability and permselectivity than the Polyetherimides prepared from 2,2'-dimethyl 4,4'-methylene dianiline (DMMDA2). However, two of the Polyetherimides prepared from 2,2',3,3'-tetramethyl 4,4'-methylene dianiline (TMMDAI) or 2,2', 5,5'-tetramethyl 4,4'-methylene dianiline (TMMDA2) possess almost the same gas permeability and permselectivity.
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Structure/permeability and permselectivity relationship of Polyetherimides from 1,4-bis(3,4-dicarboxyphenoxy) benzene dianhydride. II
European Polymer Journal, 1996Co-Authors: Yuesheng Li, Mengxian Ding, Jiping XuAbstract:Gas permeability coefficients of a series of aromatic Polyetherimides prepared from 1,4-bis(3,4-dicarboxyphenoxy) benzene dianhydride (HQDPA) and four (methylene dianiline)s with a methyl side group to H-2, CO2, O-2, N-2, and CH4 were measured under 7 atm and within a temperature range from 30 to 150 degrees C. The gas permeabilities and permselectivities of these polymers were compared with those of the HQDPA-based Polyetherimides from methylene dianiline (MDA) and isopropylidene dianiline (IPDA). The number and position of the methyl side groups on the benzene rings of the diamine residues strongly affect the gas permeabilities and permselectivities of the HQDPA-based Polyetherimides. The gas permeability of the Polyetherimide progressively increases with an increase in the number of the methyl side groups. Both the gas permeability and permselectivity of the Polyetherimides with methyl side groups are higher than those of HQDPA-MDA. The Polyetherimide prepared from 3,3'-dimethyl 4,4'-methylene dianiline (DMMDA1) possesses both higher permeability and permselectivity than the Polyetherimides prepared from 2,2'-dimethyl 4,4'-methylene dianiline (DMMDA2). However, two of the Polyetherimides prepared 2,2',3,3'-tetramethyl 4,4'-methylene dianiline (TMMDA1) or 2,2', 5,5'-tetramethyl 4,4'-methylene dianiline (TMMDA2) possess almost the same gas permeability and permselectivity.
Stephen Z. D. Cheng - One of the best experts on this subject based on the ideXlab platform.
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Multiwalled Carbon Nanotubes with Chemically Grafted Polyetherimides
Journal of the American Chemical Society, 2005Co-Authors: Jason J. Ge, Matthew J. Graham, Qing Li, Frank W. Harris, Dong Zhang, Stephen Z. D. ChengAbstract:Covalent attachment of a non-fluorinated Polyetherimide onto the surface of carboxylic acid-functionalized multiwalled carbon nanotubes (MWNTs) has been achieved via grafting reactions. This confirms for the first time that the grafting reaction occurs at the nanotube surface when the carboxylic acid-functionalized MWNTs react with the Polyetherimide with amine-terminated groups, through both amide and imide linkages formed at the interface between the carbon nanotubes and the Polyetherimide. Additionally, an increase in the average molecular weight is detected in gel permeation chromatography when the Polyetherimide is chemically attached onto the nanotubes. More interestingly, the chemical bonding at the interface provides much better interfacial adhesion and mechanical stress transfer, evidenced by a significant improvement in mechanical properties. As a result of the chemical attachment, the carbon nanotube-reinforced Polyetherimide composite films have enhanced electrical conductivity, thermal deform...
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Multiwalled carbon nanotubes with chemically grafted Polyetherimides
Journal of the American Chemical Society, 2005Co-Authors: Jason J. Ge, Haoqing Hou, Matthew J. Graham, Qing Li, Frank W. Harris, Dong Zhang, Stephen Z. D. ChengAbstract:Covalent attachment of a non-fluorinated Polyetherimide onto the surface of carboxylic acid-functionalized multiwalled carbon nanotubes (MWNTs) has been achieved via grafting reactions. This confirms for the first time that the grafting reaction occurs at the nanotube surface when the carboxylic acid-functionalized MWNTs react with the Polyetherimide with amine-terminated groups, through both amide and imide linkages formed at the interface between the carbon nanotubes and the Polyetherimide. Additionally, an increase in the average molecular weight is detected in gel permeation chromatography when the Polyetherimide is chemically attached onto the nanotubes. More interestingly, the chemical bonding at the interface provides much better interfacial adhesion and mechanical stress transfer, evidenced by a significant improvement in mechanical properties. As a result of the chemical attachment, the carbon nanotube-reinforced Polyetherimide composite films have enhanced electrical conductivity, thermal deformation temperatures, and mechanical properties. Copyright © 2005 American Chemical Society.
Jianyong Jin - One of the best experts on this subject based on the ideXlab platform.
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On Polyetherimide modified bismaleimide resins, 1. Effect of the chemical backbone of Polyetherimide
Macromolecular Chemistry and Physics, 2002Co-Authors: Xiaolin Tang, Jinchen Wang, Xianqing Cai, Qushen Zhao, Xiangyang Hua, Jun Cui, Yifu Ding, Shanjun Li, Jianyong JinAbstract:SUMMARY: Four kinds of Polyetherimides with different diamines were prepared and used to improve the toughness of bismaleimide resins composed of bis(4-maleimidediphenyl)methane and o,o9-diallyl bisphenol A. Dynamic mechanical analysis and scanning electron microscopy were used to characterize the phase struc-ture of the modified resins. The modified resins display different phase morphologies depending on the poly-etherimide backbone structure. The results indicate that the degree of phase separation leads to different mor-phologies and toughening. The fracture energy (G IC) was increased by 300% with the PIM modified system.
Vikas V. Gite - One of the best experts on this subject based on the ideXlab platform.
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High performance moisture cured poly(ether–urethane) amide coatings based on renewable resource (cottonseed oil)
Journal of Coatings Technology and Research, 2013Co-Authors: Pawan D. Meshram, Ravindra G. Puri, Amol L. Patil, Vikas V. GiteAbstract:In this investigation, polyetheramide resin was prepared through the condensation polymerization of N , N -bis (2-hydroxyethyl) cottonseed oil fatty amide (HECOFA) with bisphenol-A. It was further modified by 2,4-toluene diisocyanate (TDI) in 10–30 wt% of polyetheramide to develop a series of moisture curing urethane-modified polyetheramide resins (UMCOPEtA). The synthesized resin was characterized using ^1H NMR, ^13C NMR, FTIR and solubility in various organic solvents at room temperature. The thermal and curing behavior of the resin was investigated using thermogravimetric analysis and differential scanning calorimetric techniques. The physico-chemical properties such as hydroxyl value, iodine value, specific gravity and mechanical properties like scratch hardness, impact, and flexibility were determined by standard laboratory methods. Coatings of UMCOPEtA resin were prepared on mild steel panels to evaluate chemical resistance performance against acid, alkali, water and xylene. The newly developed UMCOPEtA coatings showed improved hardness, impact, gloss, water and chemical resistance when compared with unmodified polyetheramide coatings, and thus were found to be suitable as a high performance coating material.
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high performance moisture cured poly ether urethane amide coatings based on renewable resource cottonseed oil
Journal of Coatings Technology and Research, 2013Co-Authors: Pawan D. Meshram, Ravindra G. Puri, Amol L. Patil, Vikas V. GiteAbstract:In this investigation, polyetheramide resin was prepared through the condensation polymerization of N,N-bis (2-hydroxyethyl) cottonseed oil fatty amide (HECOFA) with bisphenol-A. It was further modified by 2,4-toluene diisocyanate (TDI) in 10–30 wt% of polyetheramide to develop a series of moisture curing urethane-modified polyetheramide resins (UMCOPEtA). The synthesized resin was characterized using 1H NMR, 13C NMR, FTIR and solubility in various organic solvents at room temperature. The thermal and curing behavior of the resin was investigated using thermogravimetric analysis and differential scanning calorimetric techniques. The physico-chemical properties such as hydroxyl value, iodine value, specific gravity and mechanical properties like scratch hardness, impact, and flexibility were determined by standard laboratory methods. Coatings of UMCOPEtA resin were prepared on mild steel panels to evaluate chemical resistance performance against acid, alkali, water and xylene. The newly developed UMCOPEtA coatings showed improved hardness, impact, gloss, water and chemical resistance when compared with unmodified polyetheramide coatings, and thus were found to be suitable as a high performance coating material.