Preparation, intermolecular motion, and thermal properties of thiodiphenyl epoxy

Chiu, Yie-Chan; Tsai, Hsieh‐Chih; Chou, I-Chen; Lin, Wenzhi; Yang, Shih-Yi; Tien, Hsin-Wen; Chen‐Chi, M.

doi:10.1002/app.32602

Cited by 7 publications

(3 citation statements)

References 50 publications

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“…Furthermore, there are comparatively few studies in the literature on the use of sulphur in epoxy resins despite some evidence of improved adhesion 14 and thermal stability. 15 It is more common, however, that sulphur-containing mercaptan resins are used as hardeners 16,17 in epoxy resin systems where the rapid curing at low temperature and excellent fluid resistance makes them ideal sealants. Sulphur-containing amino acid hardeners have also been used recently as a replacement for less environmentally friendly curing agents 18 that exhibit promising behaviour because thermal stability is unaffected by their usage.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterisation of new sulphur-containing epoxy networks

Vogel

Dingemans

Varley

et al. 2014

High Performance Polymers

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The position of sulphur within a cured epoxy amine network and its impact upon the thermal, mechanical, chemical and physical properties has been investigated in this study. Sulphur-containing epoxy resins, diglycidyl thioether of bisphenol A (DGTEBA) and diglycidyl ether of dithio diphenyl (DGTED) have been synthesised, cured and characterised and then compared with the benchmark epoxy resin, diglycidyl ether of bisphenol A (DGEBA). DGTEBA has two sulphur atoms located terminally to the epoxide groups, whilst DGTED has a sulphur atom located centrally between two phenyl groups. Evaluation of the properties and cure mechanism using 4,4 0 -diamino diphenyl sulphone (4,4 0 -DDS) as the hardener showed that when the sulphur was terminally located, the glass transition temperature, cure conversion, thermal stability, yield strain and stress decrease substantially, whilst the rate of cure and methyl ethyl ketone (MEK) ingress was comparatively higher. Near-infrared spectroscopy revealed that a competing hydrogen abstraction reaction mechanism deactivated the epoxide ring to nucleophilic attack to produce a heterogeneous network and poorer properties. In contrast, the properties and network structure of the DGTED-cured network, which had sulphur placed centrally between the diphenyl groups were similar to DGEBA except that MEK fluid ingress was reduced. The DGTEBA epoxy was also cured with other amines of varying reactivity to reveal that the hydrogen abstraction mechanism was dependent upon the reactivity of the hardener. Less reactive hardeners were dominated by the hydrogen abstraction mechanism, whilst the more reactive amines displayed a step-growth mechanism more typically associated with epoxy amine cure.

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Section: Introductionmentioning

confidence: 99%

Synthesis and characterisation of new sulphur-containing epoxy networks

Vogel

Dingemans

Varley

et al. 2014

High Performance Polymers

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“…The FTIR spectrum of EPS (Figure 2) features a strong absorption peak at 914 cm −1 , which we assign to the epoxy group, and peaks at 1,029 and 1,244 cm −1 , which we assign to C-O-C. The absorption peak for C-S is observed at 1,174 cm −1 [38][39][40]. These results indicate that the synthesized product was a sulfur-containing EPS.…”

Section: Resultsmentioning

confidence: 74%

Intrinsically Noncombustible Thermosets from Sulfur-Containing Epoxy Resin and Benzoxazines: Evaluation of Thermal and Mechanical Properties

Lyu

Fan

Qiu

2023

Advances in Polymer Technology

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Benzoxazine (BZ)-epoxy copolymers exhibit favorable mechanical properties, but their thermal and flame-retardant characteristics are impaired at high epoxy fractions. Here, we report a new type of sulfur-containing epoxy resin (EPS), which we synthesized using 4,4’-thiobisphenol (TBP) instead of bisphenol A (BA) and then blended with three sulfur-containing BZs (TBP-a, TBP-fa, and TBP-tma). The polymerization behavior of the resins was analyzed using Fourier transform infrared spectroscopy and differential scanning calorimetry for determining the optimal curing procedure. This analysis revealed that the oxazine and epoxy rings undergo ring-opening and cross-linking reactions at the same time and that double-substituted structures originating from the furan and thiophene rings appeared during the curing process. Thermogravimetric analysis showed that the addition of EPS increased the initial decomposition temperature by hindering the formation of double-substituted structures. The char yield at 800°C decreased owing to the unstable C–O–C–C–O groups derived from the ring-opening of EPS. To prepare the self-extinguishing copolymers with a char yield of 24%, a smaller quantity of BZ was needed for the EPS-based blends than for the BA-based ones. The heat release capacities—measured using micro-combustion calorimetry—of all copolymers except TBP-a/EPS were less than 300 J/g·K, demonstrating that the presence of thioether bonds and double-substituted structures resulted in excellent flame retardancy. The TBP-fa/EPS copolymer also exhibited excellent flame retardancy in cone calorimeter measurement. Finally, the glass transition temperature of the TBP-fa/EPS copolymer at a ratio of 5 : 5 (w/w) reached as high as 289°C. A TBP-fa/EPS copolymer with an epoxy content of 70% had nearly the same storage modulus (2,206 MPa) at 50°C as poly(BA-a) and thus similar mechanical properties. In summary, BZ-epoxy copolymers prepared from sulfur-containing epoxy combine the advantages of the constituent components and extend their areas of application.

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“…When comparing the two diols 4a and 4b , it can be observed that the diol THIO-ISOH retained higher weight than BPA-ISOH at temperature higher than 400 °C in nitrogen and 450 °C in air; also the char residue at high temperature (600 °C) was higher for THIO-ISOH than BPA-ISOH. This could be ascribed to a greater promotion of char formation by the sulphur in THIO-ISOH, which hindered the formation of volatile degradation products [ 28 ]; in air sulphur could also provide an additional protection at high temperature in the form of sulfate [ 43 ].…”

Section: Resultsmentioning

confidence: 99%

Microwave-assisted synthesis of isosorbide-derived diols for the preparation of thermally stable thermoplastic polyurethane

Kasmi

Roso

Hammami

et al. 2017

Designed Monomers and Polymers

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In order to prepare thermally stable isosorbide-derived thermoplastic polyurethane, the synthesis of two new chiral exo–exo configured diols, prepared from isosorbide, and two types of diphenols (bisphenol A and thiodiphenol) was described. The synthesis conditions were optimized under conventional heating and microwave irradiations. To prove their suitability in polymerization, these monomers were successfully polymerized using 4,4′-diphenylmethane diisocyanate (MDI) and hexamethylene diisocyanate (HDI). Both monomers and polymers have been studied by NMR, FT-IR, TGA, DSC; intrinsic viscosity of polymers has also been determined. The results showed the effectiveness of the synthetic strategy proposed; moreover, a dramatic reduction of the reaction time and an important improvement of the monomers yield using microwave irradiation have been demonstrated. The monomers, as well as the polymers, showed excellent thermal stability both in air and nitrogen. It was also shown that the introduction of sulphur in the polyurethane backbone was effective in delaying the onset of degradation as well as the degradation rate.

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Preparation, intermolecular motion, and thermal properties of thiodiphenyl epoxy

Cited by 7 publications

References 50 publications

Synthesis and characterisation of new sulphur-containing epoxy networks

Synthesis and characterisation of new sulphur-containing epoxy networks

Intrinsically Noncombustible Thermosets from Sulfur-Containing Epoxy Resin and Benzoxazines: Evaluation of Thermal and Mechanical Properties

Microwave-assisted synthesis of isosorbide-derived diols for the preparation of thermally stable thermoplastic polyurethane

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