POLYMER COMPOSITES
·
2025
·
IF 4.7
Yang Zheng,Guanghong Du,Yi Sun,Jiachen Wang,Wei Liu,Guanghui Cui,Zhanpeng Wu
Carbon fiber-reinforced polymer composites are commonly used in ablative materials, but achieving a balance between thermal insulation, mechanical strength, and anti-ablation performance is challenging. This study presents a series of polyphosphazenes with trichloroethoxy substituents, which enhance the mechanical and thermal properties of the synthesized polyphosphazenes. The effects of different types and amounts of fiberized carbon fillers, including carbon fibers, carbon fiber powder, and carbon nanofibers, on the poly[(2,2,2-trichloroethoxy)/(aryloxy)] phosphazene composites were investigated. The composite reinforced with 10 phr (parts per hundred rubber) of fiberized carbon fillers showed a 49.1% reduction in linear ablation rate and 31.4% in charring ablation rate, compared with the baseline. The mechanical properties of the composite and charred layer improved by 57.5% and 215%, respectively. This is due to the fact that the carbon filler facilitates the formation of dense charred layers with low porosity and high graphitization, which prevent heat and flame penetration. The fiberized carbon-reinforced polyphosphazene composites exhibit excellent ablation resistance and mechanical performance, making them ideal for high-performance thermal insulation in extreme conditions.
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高影响因子
POLYMER DEGRADATION AND STABILITY
·
2023
·
IF 5.9
Yifang He,Xinyu Cui,Zhishuo Liu,Fujie Lan,Jun Sun,Hongfei Li,Xiaoyu Gu,Sheng Zhang
Aiming to develop high performance flame-retardant epoxy resin (EP), a novel phosphorus-containing flame retardant named 6-(3-(2-hydroxyphenyl)propyl)dibenzo-[1,2]oxaphosphinine 6-oxide (HP-DOPO) was synthesized and employed as a multi-functional additive for EP with simultaneously excellent flame retardancy, transmittance, mechanical enhancement and anti-aging. With 5 wt.% loading of HP-DOPO, EP composites showed outstanding flame retardancy with a high limiting oxygen index of 35.6 % and V-0 rating in UL-94 test, while the cone calorimetric test results demonstrated that HP-DOPO could efficiently restrain the heat and smoke release. Compared with pure EP, the resultant EP/5 %HP-DOPO exhibited superior mechanical properties with 27.9 % and 56.2 % increase in tensile and impact strengths, respectively. Furthermore, HP-DOPO accelerated the curing procedure and did not sacrifice the transparency of cured EP, while anti-aging performance was obtained at the same time. The exploration of this novel multi-functional additive provided a powerful basis for the technologies and potential industrial applications of epoxy materials.
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高影响因子
PROGRESS IN ORGANIC COATINGS
·
2023
·
IF 6.6
Yaodong Zhang,Yuewen Huang,Zhijun Liu,Yihao Yang,Bin Wang,Yujie Peng
The development of coatings with high thermal resistance and strong adhesion is desirable and challenging. Herein, we firstly reported a novel bismaleimide silicone (PMI-HSi) oligomer as well as the matching titanium-containing phthalate curing agent (PAEs). Subsequently, PMI-HSi and PAEs are semi-cured by a de-ethanolization reaction in humid ambient atmosphere. Resultant prepolymer molecular skeletons comprise acylimine bonds yielding strong hydrogen bonds , benzene rings, and titanium atoms, which facilitates the stability of the prepared coatings in high-temperature conditions. Ultimately, the final coating was successfully obtained via thermal initiated radical polymerization . The DTG results indicated that the residual carbon content of PMI-HSi@PAEs50% is as high as 63.9 %. And the T d5% , T d30% and T HRI of PMI-HSi@PAEs50% were separately increased by 142.2 %, 29.2 % and 47.9 % compared with the control group. It is worth noting that PMI-HSi@PAEs50% can remain stable at a high temperature up to 600 °C, and no color changes and cracks appeared on the coating surface . All these results indicate that the as-prepared coatings exhibited excellent high temperature stability. In addition, due to the introduction of PAEs, the adhesion of PMI-HSi@PAEs50% reaches the highest grade of 0 and the hardness reaches 5H. Meanwhile, the reinforcement mechanisms were elucidated in detail. Overall, the as-prepared coating possesses high temperature resistance, strong adhesion, and great hardness, which possesses enormous potential for applications in the field of high-temperature protection.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Xing Liu,Zhenhong Xiao,Xianyong Liu,Yuling Liu,Jianqing Zhao,Shumei Liu
Recently, the development of epoxy thermosets with imide rings has received extensive attention due to their superior integrated properties, especially for thermal, mechanical and dielectric properties, compared to those of commercialized bisphenol A epoxy thermosets, yet remains substantial challenges, such as the high epoxy equivalent weight (EEW) of the epoxy prepolymers and the poor processibility of the epoxy systems. In this work, an imide-containing epoxy prepolymer (BAPT-EP) was facilely synthesized. It had a relatively low EEW of 340 g/equiv. and could be dissolved in hardener methylhexahydrophthalic anhydride (MHHPA) to give a homogeneous BAPT-EP/MHHPA system with good processibility. Thanks to the aromatic imide structures, the cured BAPT-EP/MHHPA showed improved overall properties. In particular, it had a 47.9 °C, 24.7 °C, 29.4%, 77.3% and 10.0% increase in the glass transition temperature, temperature at 5% mass loss, tensile strength, Young’s modulus and tensile toughness, respectively, compared to those of bisphenol A epoxy prepolymer (DGEBA)/MHHPA thermoset. Meanwhile, BAPT-EP/MHHPA thermoset featured good charring ability with a high char yield of 26.4% (800 °C/N 2 ), remarkable dimensional stability with a low coefficient of thermal expansion of 52.5 ppm/°C and good dielectric properties with a low dielectric constant of 3.24 at 100 MHz. This work provides an elegant strategy to prepare high-performance epoxy thermosets with imide structures, which have promising applications in electronics.
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高影响因子
Microorganisms
·
2023
·Vol. 11
·期 6
·1431
·
IF 4.5
Guoyu Wei,Wei Zhao,Anlong Hu,Mingjian Ren,Yunxiao Huang,Huayang Xu
Sorghum bicoloris cultivated worldwide. Leaf spot of sorghum, which leads to leaf lesions and yield reduction, is a prevalent and serious disease in Guizhou Province, southwest China. In August 2021, new leaf spot symptoms were observed on sorghum leaves. In this study, traditional methods and modern molecular biology techniques were used to isolate and identify the pathogen. Sorghum inoculated with the isolate GY1021 resulted in reddish brown lesion that similar to symptoms observed in the field: the original isolate inoculated was reisolated and Koch’s postulates were fulfilled. Based on morphological features and phylogenetic analysis of the internal transcribed spacer (ITS) combined sequence with β-tubulin (TUB2) and translation elongation factor 1-α (TEF-1α) genes, the isolate was identified asFusarium thapsinum(Strain accession: GY 1021; GenBank Accession: ITS (ON882046),TEF-1α (OP096445), and β-TUB(OP096446)). Then, we studied the bioactivity of various natural products and microorganisms againstF. thapsinumusing the dual culture experiment. Carvacrol, 2-allylphenol, honokiol, and cinnamaldehyde showed excellent antifungal activity, with EC50values of 24.19, 7.18, 46.18, and 52.81 µg/mL, respectively. The bioactivity of six antagonistic bacteria was measured using a dual culture experiment and the mycelial growth rate method.Paenibacillus polymyxa,Bacillus amyloliquefaciensandBacillus velezensisdisplayed significant antifungal effects againstF. thapsinum. This study provides a theoretical basis for the green control of leaf spot of sorghum.Keywords:antagonistic bacteria;natural product;leaf spot;sorghum;F. thapsinum
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PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Yuan Wang,Yuanbo Cai,Youquan Ling,Haoruo Zhang,Jinfeng Tian,Zhengguang Heng,Shengtai Zhou,Shuang Xia,Mei Liang,Huawei Zou
Flexible thermal protection materials with excellent mechanical and ablative properties were one of the key components in promoting the development of a new generation of aircraft. In the present work, a robust, strongly adhesive, and ablation-resistant PDMS coating was prepared through the covalent connection between PDMS and vinyl-functionalized epoxy resin (EAP) by hydrosilylation. The EAP synthesized by molecular design was uniformly dispersed in the PDMS matrix as an island phase-separation structure. The tensile strength, elongation at break, and shear strength of EAP-modified PDMS (EAP@PDMS) were significantly increased by 575%, 155%, and 183%, respectively, when compared with pure PDMS. Besides, the linear ablation rate (LAR) of EAP@PDMS was greatly declined, which was 80.1% lower than that of pure PDMS, exhibiting excellent ablation resistance. This work opened an avenue toward developing flexible thermal protection coatings with excellent mechanical and ablative properties for aerospace applications.
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高影响因子
EUROPEAN POLYMER JOURNAL
·
2023
·
IF 6
Muyao Gao,Tianhao Li,Wenjing Kong,Xun Sun,Li Liu,Bing Li,Yujie Song,Ming Liu
Phthalonitrile resins are one of the high temperature resistant polymers which can be potentially used for harsh environments in both military and domestic fields. The high melting points of the monomers led to short processing windows and made processing procedure challenging and energy intensive. To solve this problem, liquid phthalonitrile monomers containing flexible siloxane segments were designed and synthesized. The long bond length and large bond angle of Si-O-Si chain segments introduced flexibility into the monomers and effectively reduced the melting point to −35.9 °C. Meanwhile, the high bond energy preserved the thermal stability of the resulting cured resin. The high fluidity (viscosity of ∼ 2 Pa·s at 30 °C) allows the monomers to be processed at room temperature without additional heating. In addition, the monomers can be dissolved in common organic solvents, such as ethyl acetate and ethanol. The resins cured at 250 °C demonstrated good thermal and thermal oxygen stability. The weight loss of 5 % in argon and air at temperatures of 428.6 °C and 434.9 °C, respectively. Furthermore, blending this liquid monomer blended with powdered monomers improved both the processibility of the high melting monomers and the overall temperature resistance of the cured resin. The resin showed a weight loss of 5 % in argon and air of 534.4 °C and 532.3 °C, respectively.
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高影响因子
JOURNAL OF PHYTOPATHOLOGY
·
2024
·Vol. 172
·期 2
·e13301
·
IF 1.1
Guoyu Wei,Wei Zhao,Huayang Xu,Guangming Wang,Hualei Wang,Anlong Hu
Polygonatum cyrtonema (giant Chinese Solomon's seal) is a perennial herb belonging to the family Liliaceae, with significant medicinal and dietary value. However, a severe rhizome rot has led to a decline in the yield and quality of this species. In this study, a fungus was isolated from symptomatic rhizome samples and identified as Fusarium commune through molecular and morphological analyses. In pathogenicity tests, the identification of F. commune as the causative agent of rhizome rot was confirmed by fulfilling Koch's postulates. Biological characteristics indicated that the optimal growth conditions for F. commune were a temperature of 25°C, pH of 8, carbon source of soluble starch, nitrogen source of peptone and a photoperiod of 24 h light. In order to reduce the use of chemical fungicides and explore natural substances to control the disease, the sensitivity of F. commune to seven phytochemicals was studied. Four phytochemicals (honokiol, 2-allylphenol, magnolol and carvacrol) showed inhibitory activity, with honokiol having a 50% of the maximal effect concentration (EC 50 ) of 9.99 ± 0.14 mg/L. The results of pot experiment showed that the four phytochemicals had significant control efficacy on the rhizome rot of P. cyrtonema , and the highest control efficacy was observed with honokiol. These findings provide a scientific basis for the control of rhizome rot in P. cyrtonema .
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高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2025
·
IF 2.2
Houchun Yan,He Ma,Xuqiang Li,Shaolong Dong,Qingsong Li
To separate higher-rank phenols from the coal tar, the model oil was constructed, and the separation efficiency of various solvents was analyzed using solvent power, selectivity, and performance index. The liquid-liquid equilibrium data of cumene + {4-ethylphenol, 4-propylphenol, 2-allylphenol, and 2-isopropylphenol} + ethanolamine was measured at 298.2 K and 101.3 kPa, and the distribution coefficient and separation factor were calculated. Furthermore, the NRTL and UNIQUAC models were correlated with the LLE data, and the model parameters were tested by the GMcal_TieLinesLL tool, which shows that the results meet the Gibbs stability criteria. The separation mechanism was explored by analyzing σ-profile, deformation charge density, interaction energy, and RDG analysis.
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Houchun Yan,Yujie Zhen,Anle Zhang,Tao Li,Wenxue Lu,Qingsong Li
To separate higher-rank phenols from coal tar model compound, the quantum chemistry calculation, solvent power, and selectivity analysis evaluated the separation efficiency of polyols as solvents, and the liquid–liquid equilibrium data of toluene + {4-ethylphenol, 2-allylphenol, guaiacol, or 2-isopropylphenol} + ethylene glycol were measured in 303.2 K and 101.3 kPa. The distribution coefficient and separation factor were calculated to compare the efficiency of extracting different phenols using ethylene glycol. The molecular dynamics (MD) method investigated the mechanism of extraction of phenols by ethylene glycol, and the results are consistent with the experimental results, indicating that ethylene glycol can be used as an extractant for the extraction of higher-rank phenols from coal tar, and the extraction effect in the 4-ethylphenol-toluene system is the best. The non-bonded interaction energy, radial distribution function, and self-diffusion coefficient were discussed, which shows that the interaction force between phenols and ethylene glycol is mainly provided by electrostatic force.
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高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Shumeng Wang,Jian Wang,Xutao Ma,Zhaoqi Niu,Zongwu Zhang,Peibo Xu,Beixi Chen,Xiaoyan Ma,Shishan Yang,Xiao Hou
With the development of aerospace technology, the thermal insulation layer between the engine casing and the propellant needs to have excellent mechanical and ablative resistance properties to meet higher environmental requirements. Herein, two novel reactive phosphonitrile derivatives containing P and N heteroatoms, namely, hexa(2-allylphenoxy) cyclotriphosphonitrile (HAPPCP) and hexa(3-ethynylphenylamino) cyclotriphosphonitrile (HEACP), were designed and synthesized to crosslink with EPDM for modulating its chain structure on a molecular scale, forming P- and N-atom hybridized EPDM dense crosslinked networks, which collectively improve the mechanical and ablative resistance. Results showed that HEACP was more effective for boosting the overall performance, accompanied by improvements of 64.6% and 89.2% in tensile strength and breaking elongation, respectively, and reductions of 52.6% and 33.1% in the linear ablation rate and mass ablation rate, respectively. The ablation-condensed phase, microscopic carbon crystal structure, and the gas-phase thermal barrier mechanism were investigated to elucidate the ablative resistance mechanism.
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高影响因子
危险品化学品经营许可证（带存储）