Materials
·
2023
·Vol. 16
·期 2
·503
·
IF 3.4
Binxiao Wei,Chen Yu,Yongping Bai,Li Liu,Jinmei He
As the requirements of aerospace technology become more rigorous, the performance of solid rocket motor (SRM) cases needs to be further optimized. In the present study, a co-curing technique was used to fabricate carbon fiber reinforced polymer (CFRP)/ethylene-propylene-diene monomer (EPDM) composites whereby the properties of CFRP/EPDM composites were adjusted by varying the temperature, heating time and type of vulcanizing agent to obtain the optimum manufacturing process. The results of crosslink density (3.459 × 10−4mol/cm3) tested by nuclear magnetic resonance (NMR), a 90° peel strength test (2.342 N/mm), and an interlaminar shear test (ILSS = 82.08 MPa) demonstrated that the optimum mechanical properties of composites were obtained under the temperature 160 °C heated for 20 min with the curing agent DCP/S. The interfacial phase and bonding mechanism of composites were investigated by scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) further indicated that EPDM/DCP/S had favorable thermal stability. This will provide valuable recommendations for the optimization of the SRM shell preparation process.Keywords:carbon fiber reinforced polymer;epdm;co-curing;preparation optimization
研究领域:
航空航天材料
·
复合材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2024
·
IF 5.9
Yang Luo,Lewen Huang,Jingyu Cai,Qing Jiang,Xiafeng Liao,Haowen Zhang,Yunhong Lan,Xiangyu Yin,Linxi Hou,Longqiang Xiao
Herein, we present the synthesis and characterization of a novel phosphorus-containing epoxy co-curing agent, ANVD, fabricated via a one-pot method utilizing vanillin, 1,5-diaminonaphthalene, and DOPO as raw materials. Structural analysis conducted through FTIR and NMR spectroscopy confirmed the composition of ANVD. Differential scanning calorimetry (DSC) results indicated ANVD has significant contribution to the curing crosslinking of DGEBA, resulting in a slightly decreased T g value for EP/ANVD compared to EP/DOPO, albeit still notably higher. Thermogravimetric analysis (TGA) revealed a reduction in the T 5% and T max values of EP/ANVD, yet ANVD’s superior char-forming ability increased char residue mass at elevated temperatures. Combustion tests showcased the outstanding flame retardancy of EP/ANVD, with EP/ANVD-5 exhibiting a limiting oxygen index (LOI) value of 33.2 % and achieving a V-0 rating in the UL-94 test. Furthermore, EP/ANVD-5 displayed a notable decrease of 38.6 % and 32.1 % in pHRR and av-HRR, respectively, compared to pure EP, surpassing EP/DOPO with equivalent phosphorus content. Analysis of decomposition products in both condensed and gas phases revealed ANVD’s role in forming dense and continuous expanded char layers during combustion, releasing phosphorus radicals and non-combustible gases, thus exhibiting dual-phase flame retardant effects. Additionally, EP/ANVD-3 exhibited enhanced mechanical properties, with tensile strength and modulus increasing from 68.5 MPa and 0.75 GPa to 76.5 MPa and 0.86 GPa, respectively, compared to pure EP. Overall, the introduction of the bio-based flame retardant ANVD presents promising opportunities for the utilization of bio-based materials in flame retardancy applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2014
·Vol. 55
·期 3
·604-613
·
IF 1.441
Yuhong Liu,Xiying Zhang,Ning Gao
In the study, isocyanate-functionalized hyperbranched polyurethane (HPU NCO ) with a degree of branch of 35.2% was synthesized via an A 2 + B 3 method. This novel HPU NCO was used to fabricate a blend system with hydroxyl groups bearing benzoxazine precursor (BZ OH ) to investigate its effective on the thermal properties of BZ OH . The structure of HPU NCO is confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance spectroscopy. The curing behavior of the reactive HPU NCO /BZ OH blend is investigated via differential scanning calorimetry and FTIR analyses. HPU NCO /BZ OH blend indicates two successively broad exotherm peaks centered at 132 and 204°C, respectively, which is obviously different from that of BZ OH with one broad peak centered at 206°C. Thermogravimetric analysis results confirmed that the thermal stability was enhanced and the char yield of BZ OH was increased from 34.3 to 43.2% by cocuring with 10 wt% HPU NCO . POLYM. ENG. SCI., 55:604–613, 2015. © 2014 Society of Plastics Engineers
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
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2017
·Vol. 29
·期 1
·603-611
·
IF 1.907
Ting Chen,Xianming Chen,Meijie Wang,Peixin Hou,Cao Jie,Jilu Li,Yiting Xu,Birong Zeng,Lizong Dai
A novel halogen-free 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-containing co-curing agent, 6,6′-(1,4-phenylenebis(((4-(phenylamino)phenyl)amino)methylene))bis(dibenzo[c,e][1,2]oxaphosphinine 6-oxide) (DPN) was synthesized via a simple 1-pot or 2-step procedure with yield of 86.2% and 70.8%, respectively. The molecular structures of 4,4′-((1,4-phenylenebis(methanylylidene))bis(azanylylidene))bis(N-phenylaniline) (DPN intermediate) and DPN are characterized by FTIR, NMR, and MS. TGA tests show that the char yield of DPN/EP composites raises to 30.9% when the molar ratio of DPN to 4,4-diaminodiphenyl methane(DDM) is 20:80. T g values of DPN/EP composites tested by DSC and DMA are similar to neat epoxy resin (EP), which is due to the secondary amine in DPN that participates in the cross-linking reaction of epoxy resin. The storage modulus in the rubber stage (E′-190 °C) of flame-retardant epoxy resin is close to that of neat EP, while their tanδ's are lower, which indicates the similarity of samples' cross-linking density due to the participation of DPN in the cross-linking reaction. The results show that when the molar ratio of DPN and DDM is 5:95, the epoxy has a higher T g value and better mechanical properties than other samples. The introduction of DPN efficiently improves the flame-retardant properties of epoxy resin with V-0 rating of UL-94 vertical burning test, non-dripping, 41% of limit oxygen index (LOI) value, low peak heat release rate (PHRR), and total heat release (THR).
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2022
·
IF 11.322
Xin Jiang,Fukai Chu,Xiaoyu Luo,Yuan Hu,Weizhao Hu
Aiming to address the problems of flammability and brittleness of BMI and reduce the use of petroleum-based materials, three kinds of cardanol-based co-curing agents (CDPO, CDPC, CDCP) were synthesized and applied to prepare advanced BMI . Compared to the neat BMI, the modified BMI exhibited better thermal stability with higher decomposition temperatures and char yields. The BMI/CDCP-10 containing 4.5 wt% CDCP possessed the best flame retardancy with 50.4% reduction in PHRR , 27.5% reduction in THR and 21.2% reduction in TSP compared to those of neat BMI. Moreover, with the 4.5 wt% incorporation of CDPO, CDPC and CDCP, the impact strength of BMI was enhanced by 95%, 133.8% and 127.5% respectively, due to the flexible fatty chains and the decreased crosslinking density . The reason for different modification effects among modified BMI systems is studied from the structure of modifiers, finding that the phosphorylated cardanol with higher content of O and higher valence of P can be utilized to improve the mechanical property and fire safety of BMI. This work provides a new way to reduce the dependence on the petroleum-based materials and expand the application areas of BMI.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2022
·Vol. 34
·期 1
·419-429
·
IF 3.348
Tianwen Dai,Xinyue Jiang,Ying Ge,Huawei Zou,Pengbo Liu
Through the redistribution reaction of PPO, the hydroxyl-terminated low molecular weight PPO (PPO-OH) was prepared. Furthermore, after the reacting of PPO-OH with methacrylic anhydride, the double-bond-terminated low-molecular weight PPO (R-PPO) were synthesized, its M n was 2631 g/mol. The R-PPO were co-cured with epoxidized polybutadiene (JP-100) to prepare JP-100/R-PPO cured systems. The JP-100/R-PPO cured systems showed single-phase morphology. The co-curing reaction with R-PPO could effectively improve the thermal performance of JP-100, the glass transition temperature ( T g ) of cured JP-100/R-PPO systems raised greatly. For the cured JP-100/R-PPO (100/30) system, its T g was 192°C. The dielectric constant and dissipation factor of cured JP-100/R-PPO systems were both decreased and showed good frequency stability. The dielectric constant and dissipation factor at 1 MHz of cured JP-100/R-PPO (100/30) system were 2.61 and 0.0038, respectively, were obviously lower than those of cured JP-100 system (which were 3.10 and 0.0099, respectively). The JP-100/R-PPO systems exhibited an excellent thermal stability. The 5% weight loss temperature ( T 5% ) of cured JP-100/R-PPO system was around 340°C.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Zhengyi Zhang,Jiaoman Li,Yan Zhang,Zhenfu Jin
Lignin, which is crosslinked by ether and carbon‑carbon linkages, is a highly branched polymer consisting of phenyl propane units. And owing to the abundant phenolic hydroxyl groups and its structural heterogeneous characteristics, lignosulfonate, considered as a renewable aromatic macropolymer, can be used as co-curing agent in EP thermoset systems. In this study, kinetics of lignosulfonate (LS) and partially depolymerized lignosulfonate (DLS) as co-curing agents for applications to EP thermoset were discussed with the differential scanning calorimetry (DSC) measurement. The activation energy ( E a ) and dynamic modeling of curing reaction were obtained by the methods of non-isothermal kinetic analysis reported by Kissinger and Ozawa. The glass transition temperature ( T g ) was determined by DSC and mechanical properties of epoxy resins were carried out using the Universal Testing Machine. The LS dropped the exothermic peak temperature and E a of curing reaction of EP thermoset. Those of DLS were more active than the higher molecular weight lignosulfonate. The EP thermoset cured with DLS (EP-DLS) exhibited much higher reactivity, and the curing reaction could be occurred at lower temperature. The T g of EP-DLS has risen by 10 °C compared with the case without lignosulfonate. The tensile strength , elongation at break and impact strength of EP-DLS rose by 28.7%, 52.5% and 53.5%, respectively, than those of the epoxy resin cured with LS (EP-LS).Molecular weight of lignosulfonate could be an important factor of the curing reaction of EP thermoset. The high performance EP thermoset could be obtained by partially depolymerized lignin as co-curing agents.
研究领域:
材料科学
·
化学工程
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 14
·8559-8568
·
IF 4.036
Wei-Hua Xu,Shi-Jing Yan,Jian-Qing Zhao
Polyhedral oligomeric silsesquioxane (POSS) and a highly effective 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-based flame retardant co-curing agent (D-bp) were chemically introduced into the 4,4′-diaminodiphenyl methane (DDM)/diglycidyl ether of bisphenol A (DGEBA) epoxy system to create organic–inorganic hybrid epoxy composites with simultaneously improved flame retardancy and mechanical properties. The results revealed that POSS/D-bp/DGEBA hybrid composites exhibited excellent comprehensive performance, in which the V-0 criterion of the UL-94 test was passed and the peak of heat release rate (P-HRR) was significantly decreased from 939 to 371 kW m−2 when the phosphorus content was only 0.25 wt%. The glass transition temperature (Tg) increased by 16.2 °C and obvious improvement in the mechanical properties was also evidenced.
研究领域:
材料科学
·
化学工程
·
高分子科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2021
·
IF 4.43
Hafezeh Nabipour,Xin Wang,Sadia Batool,Lei Song,Yuan Hu
A phosphaphenanthrene-containing vanillin-derived compound (VDG) was synthesized by a one-pot nucleophilic addition reaction from vanillin , 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), and 3,5‐diamino‐1,2,4‐triazole. The molecular structure of VDG was characterized by Fourier transform infrared (FTIR), and 1 H, 13 C, and 31 P nuclear magnetic resonance (NMR) spectrometer. Various loadings of VDG were incorporated into diglycidyl ether of bisphenol A (DGEBA) as a co-curing agent together with 4, 4′-diaminodiphenylmethane (DDM) to produce an epoxy thermoset . The thermomechanical, thermal and fire-retardant properties of EP thermosets were evaluated by dynamic mechanical analyzer (DMA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL-94, and cone calorimetry . The results showed that a linear decrease in glass transition temperature with increasing loading of VDG owing to the declined cross-linking density. The cured DGEBA/DDM system with 2.0 wt% of VDG exhibited super anti-flammability in terms of a high LOI value of 37.0% and UL-94 V-0 rating, whereas the cured DGEBA/DDM and DGEBA/DDM with 2.0 wt% of DOPO systems showed no rating in UL-94 test. In addition, cone calorimetry test showed that the cured DGEBA/DDM system with 2.0 wt% of VDG exhibited a reduction of up to 47.5% and 34% for peak heat release rate and total heat release, respectively, compared to the cured DGEBA/DDM system. The enhanced flame-retardant property was attributed to the formation of the compact and continual structure of char layer residue with good thermo-oxidative stability. In addition to good anti-flammability, the cured DGEBA/DDM/VDG thermoset showed antibacterial property against E. coli , with an inhibition zone diameter of 10 mm. Thus, this bio-based co-curing agent could impart flame-retardant and antibacterial performance to epoxy for developing high performance functional thermosetting materials.
研究领域:
材料科学
·
化学
·
高分子科学
·
消防安全工程
·
生物技术
✓ 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）