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You Y, Zheng A, Wei D, Xu X, Guan Y, Chen J. Improving the thermal stability of poly[methyl(trifluoropropyl)siloxane] by introducing diphenylsiloxane units. RSC Adv 2023; 13:11424-11431. [PMID: 37063741 PMCID: PMC10091098 DOI: 10.1039/d3ra01285a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 03/31/2023] [Indexed: 04/18/2023] Open
Abstract
A series of poly(methyl(trifluoropropyl)-diphenyl siloxane) (P(MTFPS-co-DPS)) was synthesized by polycondensation of diphenylsilanediol and methyltrifluoropropylsiloxanediol. Their chemical structures were investigated by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and differential scanning calorimeter (DSC). The effect of diphenylsiloxane (DPS) units on the thermal stability of poly[methyl(trifluoropropyl)siloxane] (PMTFPS) was studied by thermogravimetric analysis (TGA), isothermal degradation tests, and pyrolysis-gas chromatography-mass spectrometry (Py-GCMS). The results showed that the thermal stability of PMTFPS improved with the introduction of DPS units into the chain. In particular, the temperature for 5% mass loss in PMTFPS increased by 72 °C under a nitrogen atmosphere. In addition, the mechanism by which the DPS units improve the thermal stability of PMTFPS was also investigated.
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Affiliation(s)
- Yang You
- School of Materials Science and Engineering, Shanghai Key Laboratory of Advanced Polymeric Materials, East China University of Science and Technology Shanghai 200237 China
| | - Anna Zheng
- School of Materials Science and Engineering, Shanghai Key Laboratory of Advanced Polymeric Materials, East China University of Science and Technology Shanghai 200237 China
| | - Dafu Wei
- School of Materials Science and Engineering, Shanghai Key Laboratory of Advanced Polymeric Materials, East China University of Science and Technology Shanghai 200237 China
| | - Xiang Xu
- School of Materials Science and Engineering, Shanghai Key Laboratory of Advanced Polymeric Materials, East China University of Science and Technology Shanghai 200237 China
| | - Yong Guan
- School of Materials Science and Engineering, Shanghai Key Laboratory of Advanced Polymeric Materials, East China University of Science and Technology Shanghai 200237 China
| | - Jianding Chen
- School of Materials Science and Engineering, Shanghai Key Laboratory of Advanced Polymeric Materials, East China University of Science and Technology Shanghai 200237 China
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Haiqi Zhang, Teng Q, Wu S. Binding Affinities and Spectroscopy of Complexes Formed by Polysiloxanes with Aniline and Chlorophenol Acetates. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2019. [DOI: 10.1134/s0036024418130125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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He Y, Zhao H, Yao M, Weiss RG. Complex new materials from simple chemistry: Combining an amino-substituted polysiloxane and carboxylic acids. ACTA ACUST UNITED AC 2017. [DOI: 10.1002/pola.28769] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Yong He
- College of Materials Science and Engineering; Beijing University of Chemical Technology; Beijing 100029 People's Republic of China
- Department of Chemistry; Georgetown University; Washington DC 20057-1227
| | - Hui Zhao
- College of Materials Science and Engineering; Beijing University of Chemical Technology; Beijing 100029 People's Republic of China
- Department of Chemistry; Georgetown University; Washington DC 20057-1227
| | - Miao Yao
- College of Materials Science and Engineering; Beijing University of Chemical Technology; Beijing 100029 People's Republic of China
| | - Richard G. Weiss
- Department of Chemistry; Georgetown University; Washington DC 20057-1227
- Institute for Soft Matter Synthesis and Metrology, Georgetown University; Washington DC 20057-1227
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Characterization of degradation products of poly[(3,3,3-trifluoropropyl)methylsiloxane] by nuclear magnetic resonance spectroscopy, mass spectrometry and gas chromatography. Polym Degrad Stab 2009. [DOI: 10.1016/j.polymdegradstab.2009.04.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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5
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Kählig H, Mayer-Helm BX. Characterization of stationary phases for gas chromatography by 29Si nuclear magnetic resonance spectroscopy. J Chromatogr A 2006; 1131:235-41. [PMID: 16919648 DOI: 10.1016/j.chroma.2006.07.061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 07/14/2006] [Accepted: 07/21/2006] [Indexed: 10/24/2022]
Abstract
Five bis(dimethylsilyl)-m-carborane-siloxane polymers with methyl, phenyl, and 2-cyanoethyl ligands were characterized by (1)H, (11)B, (13)C, and (29)Si nuclear magnetic resonance (NMR) spectroscopy. All relevant chemical shifts are reported, whereas signal assignment was confirmed by 2D NMR spectroscopy. The chemical composition of the polymers was calculated from the (1)H and (29)Si NMR spectra. Only (29)Si NMR spectroscopy was able to quantify the methoxy end group, from which the average molecular weights were calculated. The copolymer Dexsil 300 turned out to have a regular microstructure, whilst the terpolymers Dexsil 400 and Dexsil 410 have only partly regular sequences. (11)B NMR spectroscopy confirmed the m-carborane structure and revealed some low molecular weight impurities.
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Affiliation(s)
- Hanspeter Kählig
- Institute of Organic Chemistry, Vienna University, Währinger Strasse 38, A-1090 Vienna, Austria.
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Iuliucci R, Taylor C, Hollis WK. (1)H/(29)Si cross-polarization NMR experiments of silica-reinforced polydimethylsiloxane elastomers: probing the polymer-filler interface. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2006; 44:375-84. [PMID: 16477678 DOI: 10.1002/mrc.1763] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Polydimethylsiloxane (PDMS) elastomers reinforced with fumed silica exhibit unusual strength characteristics that are necessary for their designed applications. The microscopic details of the surface interaction between the polymer and silica are not well characterized. (1)H/(29)Si cross-polarization (cp) experiments are used to characterize cured and uncured samples of Dow Corning silastic 745. Changes to the cp dynamics upon curing are evident by the variation in peak intensities in the variable contact-time spectra of the two samples. Estimates of the cp relaxation parameters are reported for the cured sample. Additional information can be obtained by expanding the (1)H/(29)Si cp to a two-dimensional heteronuclear correlation experiment. Dramatic differences between the cured and uncured (1)H/(29)Si HetCor spectra are observed that are not visible in the 1D spectra. These changes can be rationalized as a dehydration of the silica surface and an increased hardening of the polymer after the curing process. Furthermore, isolation of the NMR signal corresponding to nuclei at or near the polymer-filler interface may be achieved in the 2D (1)H/(29)Si HetCor spectrum.
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Affiliation(s)
- Robbie Iuliucci
- Department of Chemistry, Washington and Jefferson College, Washington, PA 15301, USA.
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Mayer-Helm BX, Kählig H, Rauter W. Tetramethyl-p,p′-sildiphenylene ether–dimethyl, diphenylsiloxane copolymers as stationary phases in gas chromatography. J Chromatogr A 2004; 1042:147-54. [PMID: 15296399 DOI: 10.1016/j.chroma.2004.05.040] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A 33% tetramethyl-p,p'-sildiphenylene ether (SDPE)-67% dimethylsiloxane copolymer was prepared and characterized by 1H and 29Si NMR spectroscopy. The random copolymer was coated on fused-silica capillary columns and used as stationary phase in GC. Highly deactivated capillary columns with high separation efficiency and a working range from -10 to 400 degrees C were obtained. For comparison, a commercially available capillary column with an SDPE-diphenyl, dimethylsiloxane terpolymer was tested. The selectivity of SDPE phases is best described by the assumption that an SDPE unit is equivalent to two dimethylsiloxy and one diphenylsiloxy group. Both capillary columns exhibited low column bleed in combination with seriously increased elution temperatures.
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Affiliation(s)
- Bernhard X Mayer-Helm
- Department of Clinical Pharmacology, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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Mayer BX, Rauter W, Kählig H, Zöllner P. A trifluoropropyl-containing silphenylene-siloxane terpolymer for high temperature gas chromatography. J Sep Sci 2003. [DOI: 10.1002/jssc.200301575] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Mayer BX, Kählig H, Rauter W. Chromatographic properties of tetramethyl-p-silphenylene-dimethyl, diphenylsiloxane copolymers as stationary phases for gas-liquid chromatography. J Chromatogr A 2003; 993:59-70. [PMID: 12735438 DOI: 10.1016/s0021-9673(03)00319-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Seven tetramethyl-p-silphenylene-dimethyl, diphenylsiloxane copolymers were coated on fused-silica capillary columns to evaluate their properties as stationary phases in gas-liquid chromatography. The capillary columns were tested concerning their selectivity, separation efficiency, column bleed, inertness, elution temperatures, and working range. The following characteristic properties of the silphenylene unit were found: (i) the impact of the silphenylene group on the chromatographic selectivity is similar to that of two dimethylsiloxy groups and half of a diphenylsiloxy group; (ii) silphenylene-siloxane copolymers offer reduced column bleed and increased maximum allowable operating temperature in comparison to polysiloxanes, since the backbone stiffing phenylene group enhances thermal stability; (iii) the elution temperatures of analytes are increased by 15-30 degrees C on silphenylene-siloxane copolymers compared to polysiloxanes; (iv) the silphenylene unit increases the glass transition temperature of the polymers resulting in elevated minimum allowable operating temperatures.
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Affiliation(s)
- Bernhard X Mayer
- Department of Clinical Pharmacology, University School of Medicine, Vienna University, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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Mayer BX, Kählig H, Rauter W. A 50% n-octylmethyl, 50% diphenyl-polysiloxane as stationary phase with unique selectivity for gas chromatography. Analyst 2003; 128:1238-42. [PMID: 14667159 DOI: 10.1039/b309476f] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An n-octylmethyl, diphenyl-polysiloxane called SOP-50-Octyl was prepared by a condensation reaction of bis(dimethylamino) n-octylmethylsilane with diphenylsilanediol. The resulting copolymer was a gum with high molecular weight and was obtained with a yield of 80%. 1H and 29Si NMR spectroscopy revealed that the copolymer was a 52% octylmethyl, 48% diphenyl-polysiloxane with random microstructure. Small cyclic impurities could be almost quantitatively removed via a purification step. SOP-50-Octyl was used as stationary phase for the preparation of wall coated open tubular fused silica capillary columns for gas-liquid chromatography. The capillary columns exhibited high separation efficiency and high inertness. The stationary phase offered a unique selectivity due to its unique composition. The Rohrschneider-McReynolds constants indicated a low overall polarity in spite of the high phenyl content, as the polarity was distinctly decreased by the octyl substituent. Furthermore, the octyl substituent was responsible for a high column bleed, reducing the maximum allowable operating temperature to 280 degrees C. The elution temperatures of apolar compounds were increased due to increased interaction of the octyl substituent with the analytes. Some applications with volatile and semi-volatile organic compounds illustrate that SOP-50-Octyl is an excellent choice for confirmational analyses.
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Affiliation(s)
- Bernhard X Mayer
- Department of Clinical Pharmacology, University School of Medicine, Vienna University, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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Mayer BX, Zöllner P, Lorbeer E, Rauter W. A new 75% diphenyl, 25% dimethyl-polysiloxane coated on fused silica capillary columns for high temperature gas chromatography. J Sep Sci 2002. [DOI: 10.1002/1615-9314(20020101)25:1/2<60::aid-jssc60>3.0.co;2-a] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Kiridena W, Koziol WW, Poole CF, Nawas MI. Influence of diphenylsiloxane composition on the selectivity of poly(dimethyldiphenylsiloxane) stationary phases for open-tubular column gas chromatography. Chromatographia 2001. [DOI: 10.1007/bf02492494] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Mayer BX, Zöllner P, Rauter W, Kählig H. Characterization of stationary phases for gas chromatography by 29Si NMR spectroscopy. II. Silphenylene-siloxane copolymers. J Chromatogr A 2001; 917:219-26. [PMID: 11403472 DOI: 10.1016/s0021-9673(01)00705-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A series of tetramethyl-p-silphenylene-siloxane copolymers with dimethyl, 1H,1H,2H,2H-perfluorodecylmethyl and diphenyl siloxy groups was prepared. 1H and 29Si nuclear magnetic resonance spectroscopy showed that the chosen reaction conditions provided polymers with diphenyl content up to 85%. The theoretical content of the monomer units correlated well with the measured content. Signal assignments of the copolymers and their corresponding chemical shifts are summarized. Information about alternating, randomized or block sequences was obtained by 29Si nuclear magnetic resonance spectroscopy. Limitations of the method for the determination of microstructure parameters are discussed.
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Affiliation(s)
- B X Mayer
- Department of Clinical Pharmacology, Vienna School of Medicine, Austria.
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Affiliation(s)
- G A Eiceman
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces 88003-0001, USA
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