Study on the thermal behaviors of polyhedral oligomeric octaphenylsilsesquioxane (OPS)

Zhang, Donglin; Yang, Rongjie; Qin, Zhaolu; Zhang, Wenchao

doi:10.1007/s10973-022-11887-3

Cited by 8 publications

(5 citation statements)

References 24 publications

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“…The grafting reactivity during the blending processing of PhVPOSS and EVA was investigated by FTIR, XPS, and H-NMR, and the spectra are shown in Figure 2 a–f. In Figure 2 a, the weak absorption peaks at 1652 cm −1 and 1594–1430 cm −1 correspond to the stretching vibrations of the C=C bond on the vinyl and phenyl groups, and the absorption peaks at 1128 and 1043 cm −1 represent the Si-O-Si structure in the horizontal and vertical directions, respectively [ 32 , 33 ]. For the EVA/PhVPOSS composite, the stretching vibration peak of the vinyl disappeared at 1652 cm −1 , indicating a reaction between PhVPOSS and EVA during high-temperature processing.…”

Section: Resultsmentioning

confidence: 99%

Enhancing Char Formation and Flame Retardancy of Ethylene-Vinyl Acetate Copolymer (EVA)/Aluminum Hydroxide (ATH) Composites by Grafting Ladder Phenyl/Vinyl Polysilsesquioxane (PhVPOSS)

Cheng

Cong

et al. 2023

Polymers

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The ladder phenyl/vinyl polysilsesquioxane (PhVPOSS) was used to improve the flame-retardancy performances of ethylene-vinyl acetate copolymer (EVA)/aluminum hydroxide (ATH) composites due to the reactivity of its vinyl groups. FTIR, XPS, 1H NMR, and SEM-EDS data demonstrated the PhVPOSS grafting onto EVA molecular chains. The PhVPOSS improved the thermal stability of EVA/ATH composites, as shown by the thermogravimetric analysis (TGA). Furthermore, with the cone calorimeter (CONE) experiments, EVA/ATH/PhVPOSS showed better fire safety than the EVA/ATH composites, with the PHRR, PSPR, and PCOP reduced by 7.89%, 57.4%, and 90.9%, respectively. The mechanism investigations of flame retardancy revealed that the charring behaviors of the EVA/ATH/PhVPOSS composites were improved by the formation of Si-C bonds and Si-O bonds, and a more compact and denser char layer can contribute more to the barrier effect.

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Section: Resultsmentioning

confidence: 99%

Enhancing Char Formation and Flame Retardancy of Ethylene-Vinyl Acetate Copolymer (EVA)/Aluminum Hydroxide (ATH) Composites by Grafting Ladder Phenyl/Vinyl Polysilsesquioxane (PhVPOSS)

Cheng

Cong

et al. 2023

Polymers

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“…The first stage occurs at 400-510 C, which can be related to the sublimation of POSS and the second stage occurs at 560-600 C, which is related to the phenyl group detachment and destruction of caged structure. The formation of polyaromatic carbons occurs at higher temperatures about 600-900 C. 42 TGA analysis was employed to determine the impact of POSS nanoparticles on the thermal stability of PBZ resin across a range of heating rates. The TGA and derivative thermal gravimetric (DTG) curves are displayed in Figures 3 and 4, as well as, Tables 2 and 3.…”

Section: Characterization Of Synthesized Benzoxazine Monomermentioning

confidence: 99%

Thermal stability and decomposition kinetics of polybenzoxazine and oligomeric polyhedral octaphenyl silsesquioxane nanocomposites

Faghihi,

Azar,

Khonakdar

et al. 2024

Polymers for Advanced Techs

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In this study, the impact of octaphenyl polyhedral oligomeric silsesquioxane (POSS) on the thermal stability of polybenzoxazine resin at 1, 3, and 5 wt% POSS loading through dynamic thermogravimetric analysis (TGA) at heating rates of 10, 20, 30 and 40°C min−1 was investigated. Besides, the decomposition kinetics of polybenzoxazine resin (PBZ) and various nanocomposites were studied using Kissinger, Friedman, Flynn‐Wall‐Ozawa (FWO) and Coats‐Redfern (CR) models and also, the activation energies of samples were calculated. At first, benzoxazine monomer was synthesized and then nanocomposites were prepared via solution mixing method. The qualitative dispersion of nanoparticles in benzoxazine resin was examined through the utilization of scanning electron microscopy and x‐ray diffraction experiments. The results showed that the addition of nanoparticles improved the thermal stability of PBZ resin specially at 1 wt% POSS loading and at higher POSS content the thermal stability of the resin decreased. As determined by TGA, the char yield of resin was enhanced by 2.6% upon the addition of 1 wt% nanoparticles. In addition, in 1 weight percent of nanoparticles, as the heating rate rose from 10 to 40°C min−1, the Integral Program Decomposition Temperature (IPDT) has increased by about 260°C, and this increase is about 183°C compared to the resin, and also elevating the heating rate, Td (5%) and Td (10%) weight loss of samples shifted to higher temperatures. The degradation mechanism of the resin and nanocomposites was evaluated through Kissinger, Friedman, FWO and CR models. The results displayed that the addition of 1 wt% nanoparticles increased the activation energy (Ea) values of the nanocomposites compared to that of neat resin and above this filler content, the Ea values decreased. The findings derived from the FWO model indicated that the inclusion of a 1 wt% filler raised the Ea values of the first and second stages of PBZ resin decomposition from 136–200 and 151–214 kJ mol−1 to 148–210 and 180–228 kJ mol−1, respectively.

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“…In recent years, some researchers have conducted more extensive research on the synthesis and application of PSQ. [14][15][16][17][18] Preparation methods of OPS have been rigorously proposed and the intermediate species and pathways have also been discovered and investigated. It is found that the tetraol species is an intermediate for OPS.…”

Section: Introductionmentioning

confidence: 99%

Influence of monomer concentration on structures of fully condensed polyphenylsilsesquioxanes

Wu,

Qin,

Zhang

et al. 2023

High Performance Polymers

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Fully condensed polyphenylsilsesquioxanes have been prepared via the hydrolysis and condensation of the same phenyltrimethoxysilane (PTMS) monomer in different concentrations. The effect of monomer concentration on molecular structure of the final products has been thoroughly investigated. Cage structured polyphenylsilsesquioxane (OPS) and ladder-like structured polyphenylsilsesquioxane (L-PPSQ) can be selectively synthesized from the same starting materials at lower and higher initial monomer concentrations. Meanwhile, online infrared detector, React IR TM15 was used to monitor the real time variation of the concentration and characteristic absorption peaks of any intermediate products that may exist. Then, React IR TM15 coupled with 29Si nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC) and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) were used to monitor and identify the intermediate species during the reaction. Mechanism studies indicated that the condensation reaction of OPS and L-PPSQ both proceed through a T1 structure dimer, which was formed by the quick hydrolysis of the PTMS monomer. As confirmed by 29Si-NMR, GPC and MALDI-TOF-MS, the synthesis mechanisms of OPS and L-PPSQ during the hydrolysis-condensation reactions were delineated.

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Study on the thermal behaviors of polyhedral oligomeric octaphenylsilsesquioxane (OPS)

Cited by 8 publications

References 24 publications

Enhancing Char Formation and Flame Retardancy of Ethylene-Vinyl Acetate Copolymer (EVA)/Aluminum Hydroxide (ATH) Composites by Grafting Ladder Phenyl/Vinyl Polysilsesquioxane (PhVPOSS)

Enhancing Char Formation and Flame Retardancy of Ethylene-Vinyl Acetate Copolymer (EVA)/Aluminum Hydroxide (ATH) Composites by Grafting Ladder Phenyl/Vinyl Polysilsesquioxane (PhVPOSS)

Thermal stability and decomposition kinetics of polybenzoxazine and oligomeric polyhedral octaphenyl silsesquioxane nanocomposites

Influence of monomer concentration on structures of fully condensed polyphenylsilsesquioxanes

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