MACROMOLECULAR MATERIALS AND ENGINEERING
·
2022
·Vol. 307
·期 11
·2200408
·
IF 4.402
Wen-Hua Zhao,Jing-Wen Wang,Guo-Chao Zhuang,Dong-Yue Liu,Chuang-Chuang Sun
A reactive flame retardant (DTP) is successfully synthesized and characterized, and then incorporated into epoxy resin (EP) as a co-curing agent. The thermal stabilities and flame-retardant properties of epoxy thermosets are evaluated. Compared to neat EP, the thermogravimetric analysis (TG) results show that the thermal decomposition rate of EP/DTP is reduced by 45% and the char yield at 750 °C is increased by 67%, when the addition amount of DTP is 12 wt%. In the cone calorimetry test (CCT), the values of the peak of heat release rate (pk-HRR), total heat release (THR), total smoke produce (TSP), and average of effective heat combustion (av-EHC) of EP-DTP-12 are exhibited a reduction of 36.6%, 26.4%, 40.5%, and 23.6% relative to neat EP, respectively. Meanwhile, the value of the limiting oxygen index (LOI) of EP/DTP-12 can reach 34.83%, and 6 wt% or more loading of DTP make EP/DTP pass the V-0 rating in the UL-94 test. Moreover, the flame-retardant mechanism is investigated by thermogravimetric analysis/infrared spectrometry (TG-IR) and scanning electron microscopy (SEM), which can be summarized into two aspects: the quenching effect of phosphorus-containing radicals and diluting effect of nonflammable gases in the gas phase, and the barrier effect of char layer in the condensed phase.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 66
·37631-37642
·
IF 2.936
Haiyang Wu,Rong Hu,Birong Zeng,Li Yang,Ting Chen,Wei Zheng,Xinyu Liu,Weiang Luo,Lizong Dai
In order to develop new phosphorus–nitrogen-containing flame retardants, three novel compounds of DOPO-substituted aminophenyl-s-triazine (TAT-DOPO) with different P/N element ratios were synthesized by Kabachnik–Fields reaction. TAT-triDOPO possessing three DOPO units in one molecule exhibited the best thermal stability. Besides, TAT-triDOPO and TAT-hexaDOPO possessing active hydrogen displayed the characteristics of reactive-type retardant, while TAT-enneaDOPO without active hydrogen represented additive-type retardant. The influences of three TAT-DOPO compounds on the thermal stability, flame retardancy and mechanical properties of the cured EP composites were investigated. Compared with pure EP, the char yields of EP/TAT-DOPO were increased. The LOI value and the UL-94 ratings of EP/TAT-triDOPO with a 5% loading were improved to 34.0% and V-0 grade. The PHRR, THR and HRC of EP/TAT-triDOPO were decreased by 25.7%, 21.1% and 25.4%, respectively. Furthermore, the incorporation of TAT-triDOPO could also improve the flexural strength and elastic modulus of cured EP. It was explained that the existence of active hydrogen atoms within TAT-triDOPO molecule can act as effective chemical cross-linking points in EP network. Finally, based on the SEM and TGA-FTIR analysis of pyrolytic products of cured EP/TAT-DOPO, it was deduced that the prepared TAT-DOPO flame retardant could exhibit both condensed phase and gas phase flame-retardancy mechanism.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Inorganic and Organometallic Polymers and Materials
·
2022
·Vol. 32
·期 5
·1902-1912
·
IF 3.518
Song Dongdong,He Chuang,Zhang Gang,Wang Yanlin,Liang Zuoqin,Jiang Zicheng,Ma Su
Currently, the issue of natural flammability of unsaturated polyester resin (UPR) severely restrains its application. In this study, polymeric flame retardant poly methyl vinyl di (1-thio-2,6,7-trioxal-1-phosphabicyclo [2.2] octane-4-methoxy) silane (PMVDOS) with P–S–Si-based cage unit was synthesized. The UPR/PMVDOS composites were prepared by adding different ratios of PMVDOS into UPR. The flame-retardant properties and the char layer structure of UPR samples were evaluated via the limiting oxygen index (LOI), vertical burning test, cone calorimeter test, scanning electron microscopy, laser Raman spectroscopy, and X-ray photoelectron spectroscopy. The results showed that UPR/PMVDOS composites reached the UL-94 V-0 rating with the LOI value of 27.8%, and the carbon residue increased from 4.9% for pure UPR to 14.9% when the content of PMVDOS was 18 wt%. The peaks of heat release rate, total heat release, and total smoke production were comparatively reduced. The flame-retardant mechanism of PMVDOS mainly acted on the condensed phase. The surface of the matrix was covered with the polymer containing phosphorous and silicon dioxide particles, preventing the escape of flammable volatiles and isolating the exchange of oxygen and heat, thus, the degradation of the matrix could be inhibited. This research provides a solution to improve the flame retardancy of UPR.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2019
·
IF 3.78
Daikun Jia,Xiaoyan Guo,Jiyu He,Rongjie Yang
Endowing rigid polyurethane foam (PUF) with a good fire-retardancy is essential for improving fire safety. Chemical improvement in fire-retardancy by using reactive-type flame retardants is better because of the disadvantages of traditional additive-type flame retardants. A reactive flame retardant tri-glycidyl phosphate (POG), which was synthesized by using phosphorus oxychloride and glycidol , was bound to the cross-linked network structure of PUF. The effects of POG on the physical-mechanical properties, morphology, thermal stability and fire-retardancy of PUF system were systematically investigated. Research results showed that POG resulted in an improvement in the thermal insulation ability and a slight decrease in the compressive strength of PUF. Furthermore, thermogravimetric analysis certified that the thermal stability and the char yield at 700 °C of PUF were significantly enhanced by incorporating POG. The limiting oxygen index increased to 22.3% with rising loading of POG. Moreover, a 30.2% decline in total heat release was achieved, the time to flameout was significantly shortened. Additionally, the vertical burning test illustrated that POG effectively limited the spread of flame and eliminated melt dripping. Further study confirmed that the fire-retardancy of PUF was significantly improved by inhibiting flame in the gas phase and charring in condensed phase.
研究领域:
材料科学
·
防火安全工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）