scholarly journals Polyhedral oligomeric silsesquioxane (POSS)-modified phenolic resin: Synthesis and anti-oxidation properties

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 316-326
Author(s):  
Bing Wang ◽  
Minxian Shi ◽  
Jie Ding ◽  
Zhixiong Huang

Abstract In this work, octamercapto polyhedral oligomeric silsesquioxane (POSS-8SH) and octaphenol polyhedral oligomeric silsesquioxane (POSS-8Phenol) were successfully synthetized. POSS-8Phenol was added into the synthesis process of liquid thermoset phenolic resin (PR) to obtain POSS-modified phenolic resin (POSS-PR). Chemical structures of POSS-8SH, POSS-8Phenol, and POSS-PR were confirmed by FTIR and 1H-NMR. TG and DTG analysis under different atmosphere showed that char yield of POSS-PR at 1,000°C increased from 58.6% to 65.2% in N2, which in air increased from 2.3% to 26.9% at 700°C. The maximum pyrolysis temperature in air increased from 543°C to 680°C, which meant better anti-oxidation properties. XRD results confirmed both POSS-8Phenol and POSS-PR-generated crystalline SiO2 in air, which could explain the improvement of anti-oxidation properties. SEM showed that the POSS-PR had phase separation during curing process. Finally, carbon fiber fabric-reinforced POSS-PR (C-POSS-PR) was prepared to verify the anti-oxidation properties of POSS-PR.

e-Polymers ◽  
2018 ◽  
Vol 18 (3) ◽  
pp. 237-245 ◽  
Author(s):  
Ding Yaoke ◽  
Zhanglin Yuan ◽  
Jincheng Wang

AbstractA novel trisilanol polyhedral oligomeric silsesquioxane-containing phosphorus (DPCP-TPOSS) was synthesized from trisilanolphenyl polyhedral oligomeric silsesquioxane (TPOSS) and diphenyl chlorophosphate. DPCP-TPOSS was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), hydrogen nuclear magnetic resonance (1H-NMR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Then a novel type of room-temperature vulcanized silicone rubber (RTV)/DPCP-TPOSS composite was prepared. Properties such as swelling behavior, tensile strength, elongation at break, thermal stability and flame retardance were researched and compared. Results showed that RTV/DPCP-TPOSS-3 and RTV/DPCP-TPOSS-5 composites exhibited the best tensile strength and elongation at break, 4.5 MPa and 427%, which was 25% and 32% higher than that of pure RTV. TGA tests demonstrated that RTV/DPCP-TPOSS-3 owned the highest char residues, 39.7%. Tmax of RTV composites was increased from 531.9°C to 557°C with the incorporation of DPCP-TPOSS. Moreover, the addition of DPCP-TPOSS led to considerably increase of the fire-retardant performance.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1182
Author(s):  
Degang Wang ◽  
Jie Ding ◽  
Bing Wang ◽  
Yingluo Zhuang ◽  
Zhixiong Huang

In this paper, a new polyhedral oligomeric silsesquioxane containing a phenol group (POSS-Phenol) is prepared through the Michael addition reaction, which is added to the synthesis of phenolic resin as a functional monomer. Infrared spectroscopy (IR) is used to demonstrate the chemistry structure of the synthesized POSS modified phenolic resin. After introducing POSS into the resole, a comprehensive study is conducted to reveal the effects of POSS on the thermal degradation of phenolic resin. First, thermal degradation behaviors of neat phenolic resin and modified phenolic resin are carried out by thermogravimetric analysis (TGA). Then, the gas volatiles from thermal degradation are investigated by thermogravimetric mass spectrometry (TG-MS). Finally, the residues after thermal degradation are characterized by X-ray diffraction (XRD). The research indicates that POSS modified phenolic resin shows a better thermal stability than neat phenolic resin, especially at high temperatures under air atmosphere. On the one hand, the introduction of the POSS group can effectively improve the release temperature of oxygen containing volatiles. On the other hand, the POSS group forms silica at high temperatures under air, which can effectively inhibit the thermal oxidation of phenolic resin and make phenolic resin show a better high-temperature oxidation resistance.


2002 ◽  
Author(s):  
Brent Viers ◽  
Shawn Phillips ◽  
Timothy Haddad ◽  
Alan Esker ◽  
Joe Polidan

2020 ◽  
Vol 26 (26) ◽  
pp. 3147-3160
Author(s):  
Saeedeh Ahmadipour ◽  
Jaleh Varshosaz ◽  
Batool Hashemibeni ◽  
Leila Safaeian ◽  
Maziar Manshaei

Background: Polyhedral oligomeric silsesquioxane (POSS) is a monomer with silicon structure and an internal nanometric cage. Objective: The purpose of this study was to provide an injectable hydrogel that could be easily located in open or closed bone fractures and injuries, and also to reduce the possible risks of infections caused by bone graft either as an allograft or an autograft. Methods: Various formulations of temperature sensitive hydrogels containing hydroxyapatite, Gelrite, POSS and platelets rich plasma (PRP), such as the co-gelling agent and cell growth enhancer, were prepared. The hydrogels were characterized for their injectability, gelation time, phase transition temperature and viscosity. Other physical properties of the optimized formulation including compressive stress, compressive strain and Young’s modulus as mechanical properties, as well as storage and loss modulus, swelling ratio, biodegradation behavior and cell toxicity as rheometrical parameters were studied on human osteoblast MG-63 cells. Alizarin red tests were conducted to study the qualitative and quantitative osteogenic capability of the designed scaffold, and the cell adhesion to the scaffold was visualized by scanning electron microscopy. Results: The results demonstrated that the hydrogel scaffold mechanical force and injectability were 3.34±0.44 Mpa and 12.57 N, respectively. Moreover, the scaffold showed higher calcium granules production in alizarin red staining compared to the control group. The proliferation of the cells in G4.5H1P0.03PRP10 formulation was significantly higher than in other formulations (p<0.05). Conclusion: The optimized Gelrite/Hydroxyapatite/POSS/PRP hydrogel scaffold has useful impacts on osteoblasts activity, and may be beneficial for local drug delivery in complications including a break or bone loss.


2016 ◽  
Vol 72 (12) ◽  
pp. 244-250 ◽  
Author(s):  
Hisai Ueda ◽  
Wataru Okumura ◽  
Hideyuki Uematsu ◽  
Shuichi Tanoue

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