JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 15
·10784-10797
·
IF 2.993
Bo Caiying,Hu Lihong,Chen Yong,Yang Xiaohui,Zhang Meng,Zhou Yonghong
A novel phosphorus-containing cardanol (PCC) derived from cardanol—a renewable meta -substituted phenol and harmful by-product of the cashew industry—in combination with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was used to produce bio-based phenolic foams (PFs). The properties of the PFs were then characterized in detail. The PCC was fully characterized by using Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ( 1 H NMR), while the thermal degradation was studied and monitored by thermogravimetry coupled to FTIR (TGA/FTIR) and TGA coupled with mass spectrometry (TGA/MS). It was found that PCC exhibited high thermal stability. The total heat release, peak heat release rate and mean heat release rate of PF containing 4% PCC decreased by 13.55, 33.43 and 13.42%, respectively, in comparison with pristine PF. The enhanced flame-retardant behavior was attributed to the free radicals PO· produced during combustion, which captured free radicals in the gas phase; moreover, the phosphaphenanthrene group may create a char residue barrier against the further combustion of the polymer. Meanwhile, bio-based PFs showed excellent mechanical properties, as the compressive and flexural strength of PF with 4% PCC increased by 79.59 and 20.98%, respectively, in comparison with pristine PF. The pulverization ratio of bio-based PFs was reduced with the increase in PCC content. The findings in this study demonstrate that PCC could be used as a phenol substitute in the synthesis of PFs to overcome their intrinsic brittleness and high flammability.
研究领域:
材料科学
·
化学工程
·
可持续化学
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2022
·
IF 11.322
Zhenting Yin,Wei Cai,Jingyi Lu,Bin Yu,Bibo Wang,Lei Song,Yuan Hu
With the advent of the 5G era, preparing conductive polymers to accomplish electromagnetic interference (EMI) shielding, mechanical enhancement, and flame retardancy are of vital importance. Graphite felt (GF) acts as a three-dimensional structure and organophosphorus derivatives containing different valences work as a flame retardant to form a novel EP composite. With GF incorporated into EP, EMI shielding effectiveness (SE) achieves around 60 dB, and absorption is dominated in the X band (8.2–12.4 GHz). Meanwhile, GF could exert a fiber reinforcement effect to enhance the mechanical properties of EP composites, tensile strength and impact strength of EP/GF are increased by 19.1% and 64.2%, respectively. However, owing to the “wick effect” of GF, 20 wt% DOPO-PEPA is added to acquire flame-retardant EP composites. Herein, a potential strategy broadens applications of EP composites in the high-end field and is provided to prepare polymer composites .
研究领域:
材料科学
·
电气工程
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Fubin Luo,Shuguang Yang,Zhehang Shi,Yingbing Zou,Hongzhou Li
Epoxy-based vitrimers appear as a promising alternative to common epoxy materials. Nevertheless, the possibility of epoxy vitrimers in practical applications is limited by their high flammability. In this study, a novel bio-based casein phosphopeptide chelating zinc (CPP-Zn) is purposely developed, specifically designed to serve as a flame retardant and smoke suppressant for epoxy vitrimer, operating through a condensed phase mechanism. To further enhance the fire safety of epoxy resins, DOPO derivative (DDP) is synthesized through grafting with bio-based itaconate and subsequently used as a synergistic flame retardant in combination with CPP-Zn. DDP exhibits gas phase flame retardant mechanism through the release of free radical scavangers generated during combustion. As a result of the combination of condensed and gas phase effect, the composite achieves self-extinguishing within 1 second, attains a V-0 rating in UL-94 testing, and boasts an LOI of 32.3 %. Additional, it shows a remarkable 73.7 % reduction in heat release rate (HRR) and 27.2 % in total smoke production (TSP) compared with neat epoxy vitrimer. The experimental results also evidence that the characteristic features of vitrimers, self-healing and recyclability, have been retained in the prepared flame-retarded composites. The remolded 50D/EST-25Cz is still able to maintain 72.2 % of its tensile strength . This opens promising avenues for the development of highly fire-safe and eco-friendly epoxy resins.
研究领域:
材料科学
·
化学工程
·
消防安全工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2018
·
IF 1.047
Shuang Yang,Yefa Hu,Qiaoxin Zhang
In this article, a phosphorus–nitrogen-containing flame retardant (DOPO-T) was successfully synthesized by nucleophilic substitution reaction between 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and cyanuric chloride. The chemical structure of DOPO-T was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance (NMR) and phosphorous-31 NMR, and elemental analysis. DOPO-T was then blended with diglycidyl ether of bisphenol-A to prepare flame-retardant epoxy resins. Thermal properties, flame retardancy, and combustion behavior of the cured epoxy resins were evaluated by differential scanning calorimetry, thermogravimetric analysis, limited oxygen index (LOI) measurement, UL94 vertical burning test, and cone calorimeter test. The results indicated that the glass transition temperature (Tg) and temperature at 5% weight loss of epoxy resin (EP)/DOPO-T thermosets were gradually decreased with the increasing content of DOPO-T. DOPO-T catalyzed the decomposition of EP matrix in advance. The flame-retardant performance of EP thermosets was significantly enhanced with the addition of DOPO-T. EP/DOPO-T-0.9 sample had an LOI value of 36.2% and achieved UL94 V-1 rating. In addition, the average of heat release rate, peak of heat release rate, average of effective heat of combustion, and total heat release (THR) of EP/DOPO-T-0.9 sample were decreased by 32%, 48%, 23%, and 31%, respectively, compared with the neat EP sample. Impressively, EP/DOPO-T thermosets acquired excellent flame retardancy under low loading of flame retardant.
研究领域:
材料科学
·
高分子化学
·
消防安全工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER JOURNAL
·
2022
·Vol. 54
·期 8
·995-1008
·
IF 3.135
Fei Xuan,Zhang Xiaoqin,Liu Jingkai,Wang Jinggang,Liu Xiaoqing
A biobased diol (BDBE) is synthesized from vanillin, guaiacol, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) to generate a series of fire-retardant polyesters (PECBFs) via melt polymerization with ethylene glycol (EG), 1,4-cyclohexanedimethanol (CHDM), and 2,5-furandicarboxylic acid (FDCA). The chemical structure, sequence distribution, and molecular weights of the obtained polyesters are confirmed by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The results show that BDBE units contribute positively to the high glass transition temperature ( T g ) and fire retardancy, while the CHDM moiety provides flexibility and chain propagation activity. As the content of BDBE is increased from 0 to 25%, the T g of PECBFs increases from 82 to 95 °C, and the limiting oxygen index (LOI) increases from 22.4 to 27.5%. In the UL-94 combustion test, when BDBE units are more than 15%, the samples almost self-extinguish immediately once the flame is moved away. Their mechanical properties are also investigated, and their tensile modulus is stabilized between 1.7 and 1.8 GPa, while the elongation at break ranges from 5 to 56%. Biobased polyesters demonstrating satisfactory properties are reported in this work.
研究领域:
材料科学
·
聚合物化学
·
阻燃性
·
生物基材料
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Jie Yang,Ao Zhang,Yuxin Chen,Linsheng Wang,Meixian Li,Hongyu Yang,Yanbei Hou
Biomass materials are considered to be excellent candidates to replace petroleum-based materials, but inherent flammability limits their applications. In this work, biomass aerogel (BA) was prepared by freeze-drying method from sodium alginate (SA) and polyvinyl alcohol (PVA). To improve fire safety of BAs, a core–shell structured ZIF-67@Cobalt coordination compound was successfully synthesized, which was surface functionalized by 3,5-diamino-1,2,4-triazole and 9,10-dihydro-9-oxo-10-phospho-diphenyl-10-oxide (DOPO), named as DOPO-NH 2 -ZIF-67. The addition of DOPO-NH 2- ZIF-67 (2 wt%) outstandingly improved fire safety of BA, in contrast to neat BA, peak heat release rate, peak smoke production rate, and total smoke production were reduced by 66.6%, 85.10%, and 72.76%, respectively. Furthermore, the incorporation of ZIF-67 and its derivatives has no adverse effect on the thermal insulation performance of BA composites and significantly improved their compressive strength from 0.27 MPa to 1.76 MPa. Preparation of core–shell structured ZIFs rich in active groups furnishes a conceivable way to synthesize an effective flame retardant, and a prospective method for the fabrication of aerogel insulation materials with green and economical additive-free technology is proposed.
研究领域:
材料科学
·
化学工程
·
消防安全工程
·
可持续材料
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 27
·13078-13096
·
IF 4.682
Xie Ruihang,Yuan Yexin,Sun Pengbo,Liu Zhe,Ma Jinpeng,Yang Guorui,Wang Kui,Li Ming,Shang Lei,Ao Yuhui
The preparation of bio-based epoxy resin with excellent thermal properties and flame retardant properties from green renewable resources had attracted extensive attention in recent years. Starting from the driving structural properties, the purpose of this study is to prepare multifunctional triglycidylester- diphenolic acid- bio-based epoxy (TDBE) with diphenolic acid (DPA), triglycidyl isocyanurate (TGIC), and 9,10-dihydro-9-oxa-10-phosphophenanthrene 10 oxide (DOPO) as raw materials. TDBE/DDM and bisphenol A epoxy resin curing agent (DGEBA/DDM) was prepared with 4,4 '- diaminodiphenylmethane (DDM) as curing agent. TDBE/DDM has excellent fire safety. LOI value rose from 24.5 to 42.0%, and the UL-94 test level passes V-0 level. In the cone calorimeter test, the peak heat release rate (pHRR) is decreased by 69.3%. Besides, the lap shear TDBE adhesive strength was 42.9 MPa, which increased by 62.5%. This new multifunctional bio-based flame retardant epoxy resin provides a broader application prospect for high-performance materials. Graphical Abstract
研究领域:
材料科学
·
化学工程
·
可持续化学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2021
·
IF 9.078
Hao Wang,Jun Yuan,Zongmin Zhu,Xianze Yin,Yunxuan Weng,Zhaojia Wang,Feihua Yang,Jiayu Zhan,Hua Wang,Luoxin Wang
It is always a challenge to prepare multifunctional epoxy resins (EP) composites with excellent flame retardance, mechanical property and high transparency. In this work, a reactive flame-retardant (BDO) was synthesized from DOPO, 3,5-diamino-triazolz and thiophene-2-formaldehyde, and taken to prepare EP/BDO composites. Surprisingly, benefitting from the synergy of efficient flame retardant unit (DOPO structure), catalytic curing unit (triazole structure) and optical functional structure (thiophene-2-formaldehyde), the EP composites with excellent comprehensive performance was obtained. In detailed, after adding only 5 wt% BDO, the EP composites passed the UL-94 V-0 level, and the limiting oxygen index was increased to 33% from 22.5% of neat EP. At the same time, EP/BDO-5 showed obvious heat suppression and smoke suppression effects. Besides, EP/BDO-5 presented excellent mechanical strength , that the tensile strength and bending strength were increased by 25% and 30% compared with neat EP. Moreover, EP/BDO composites maintained the same good light transmittance as neat EP, and also presented enhanced T g and dielectric property . In addition, the dual phase flame-retardant mechanism was revealed through systematically analyzing residues after combustion and the gaseous phase products of flame retardant. The above results indicated EP/BDO composites with excellent comprehensive performance possessed a great potential application in high-performance composites fields.
研究领域:
材料科学
·
高分子化学
·
复合材料
✓ 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）