Polymers
·
2023
·Vol. 15
·期 10
·2361
·
IF 5
Ting Pan,Zhenhua Su,Yue Yan,Xiaofei Zhu,Fan Qi,Lianbin Wu
As a bridge between the coating and the substrate, the primer has a direct impact on the adhesion performance of silicone resin thermal protection coating. In this paper, the synergistic effects of an aminosilane coupling agent on the adhesion performance of silane primer were investigated. The results show that silane primer containing N-aminoethyl-3-aminopropylmethyl-dimethoxysilane (HD-103) formed a continuous and uniform film on the surface of the substrate. Two amino groups of HD-103 were conducive to moderate and uniform hydrolysis of the silane primer system, and the introduction of dimethoxy groups was more conducive to the improvement of interfacial layer density and the formation of the planar surface structure, thus enhancing the bond strength at the interface. When the content was 13 wt%, it exhibited excellent synergistic effects on adhesive properties, and the adhesive strength reached 1.53 MPa. The possible morphology and composition of the silane primer layer were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). A thermogravimetric infrared spectrometer (TGA-IR) was used to analyze the thermal decomposition of the silane primer layer. The results showed that the alkoxy groups in the silane primer were first hydrolyzed to form Si-OH, and then the dehydration and condensation reactions between Si-OH and the substrate formed a firm network structure.Keywords:aminosilane coupling agent;synergistic effects;silane primer;adhesion property;silicone resin thermal protection coating
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2020
·
IF 4.469
Junfei Ou,Fajun Wang,Wen Li,Menghua Yan,Alidad Amirfazli
A super hydrophobic fabric (SF) has been fabricated by a simple immersion of the pristine cotton fabric into the composite silanes solution of hexadecyltrimethoxysilane (HDTMS) and methyltrimethoxysilane (MTMS). However, the cotton fabric treated by HDTMS solely possesses much inferior hydrophobicity as compared with the so-obtained SF and the cotton fabric treated by MTMS remains super hydrophilic. The methyl group in MTMS may be helpful for the long alkyl chain in HDTMS to form a well-ordered structure and thus the hydrophobicity of the composite silane is enhanced. The other benefits of adding MTMS to HDTMS are the shortening of the treating time to obtain the optimum hydrophobicity, which is 4 h for HDTMS and 1.5 h for the composite silanes, and the improving of the laundering / abrading durability of the SF. This work discloses new ways in understanding the silanes interaction and enlightens us on exploiting durable SF for practical application.
研究领域:
材料科学
·
纺织工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2016
·
IF 3.958
Futing Li,Youxin Li
A novel catalyst by preparing silica supported ethylenediaminetetraacetic acid (EDTA) platinum complex was developed. The preparation conditions, such as heating temperature and solvent types, were optimized. The catalyst was phosphine-free and sulfur-free which was characterized by infrared spectroscopy (IR), energy dispersive X-ray spectrometer (EDS), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), ultraviolet spectroscopy (UV) and atomic absorption spectroscopy (AAS). Its catalytic activity was evaluated by catalyzing solventless hydrosilylation reactions. In the hydrosilylation reaction between 1-hexene and methyldicholosilane, the new catalyst showed a higher catalytic activity than that provided by Spiere’s catalyst. Moreover, the new catalyst could be reused for 12 times without obvious loss of catalytic activity. To confirm its practical feasibility, catalyzing the hydrosilylation reaction between 1-octene and methyldichlorosilane was performed. Our results indicated that the new catalyst can efficiently catalyze the hydrosilylation reaction.
研究领域:
化学
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材料科学
·
催化反应
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Zijian Zhang,Xinbo He,Tao Zhang,Hongda Guan,Xuanhui Qu
The infiltration has the advantages of high efficiency and near net forming, making it the mainstream method for preparing diamond/SiC composite. However, no pressure was applied during the infiltration and the SiC matrix originated from the silicon-carbon reaction, resulting in a low diamond content and a large amount of residual silicon. This makes it difficult to further improve the properties of the composite, especially the thermal conductivity. Therefore, reaction bonded SiC (RB-SiC) was proposed as the matrix to reduce silicon content, and composition design was carried out to obtain high content of diamond. The results showed that in the prepared composite, the diamond content (61.14 vol%) reached the theoretical maximum of 90.43 %, and the silicon is only 4.79 vol%. Therefore, the thermal conductivity of composite can reach up to 665.47 W/mK. In addition, the influence of SiC particle size on phase composition, microstructure, and properties was analyzed.
研究领域:
材料科学
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复合材料
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 41
·25158-25169
·
IF 3.361
Zheng Wang,Mei-chen Liu,Zhi-yuan Chang,Hui-bo Li
In this research, the graft modification mechanism of coupling agent vinyl triethoxysilane (KH-151) to macroporous silica gel was studied using a combination of multiple methods. SEM, FTIR, RAMAN, NMR and XPS were used to characterize the silica gel before and after grafting, determining the mechanism of the grafting reaction of the silane coupling agent. On this basis, the grafting rate of the coupling agent was accurately calculated by TGA weight loss. From the results of characterization, it can be seen that the coupling agent molecules have two connection types on the surface of silica gel, and the ratio of the two types is 43.51% and 56.49% respectively. The influences of hydration degree of the silica gel, coupling agent dosage and reaction temperature on the grafting rate were explored, and the optimal reaction conditions for the modification of macroporous silica gel were determined by the coupling agent through orthogonal experiments, that is, the hydration degree of silica gel of 10%, a coupling agent dosage of 12 mL, and a reaction temperature of 80 °C. Under optimal reaction conditions, the average grafting rate of the coupling agent vinyl triethoxysilane (KH-151) on macroporous silica gel is as high as 91.03%.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Coatings
·
2019
·Vol. 9
·期 10
·605
·
IF 2.33
Jianye Ji,Xin Ge,Weijie Liang,Xiaoyan Pang,Ruoling Liu,Shuyi Wen,Jiaqi Sun,Xunjun Chen,Jianfang Ge
To overcome the inherent limitation that the preparation of high molecular weight MQ copolymers (Mw ≥ 30,000 g/mol) via the hydrolysis and condensation of solicate salts generally results in an intractable gel, vinylphenyl-containing MQ silicone resin with a high molecular weight was designed and synthesized through the hydrosilylation reaction of vinyl-containing MQ silicone resin and linear poly(diphenylsiloxane) with two terminal Si–H bonds. The weight average molecular weight of these modified copolymers reported here is at least 30,000 dal·mol−1. These polymers have favorable thermal stability and a higher refractive index than that of the base resin due to the formation of novel regular macromolecular structures and the introduction of phenyl groups. These inorganic/organic hybrid materials could be used as a potential component for temperature-resistance electronics adhesive, heat-resistant coatings and high-performance liquid silicone rubber. Moreover, the proposed process also provides a possibility to choose higher molecular weight MQ silicones according to application requirements.Keywords:MQ silicone resin;modified;hydrosilylation;high molecular weight
研究领域:
材料科学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2019
·Vol. 11
·期 7
·1142
·
IF 3.164
Jianye Ji,Xin Ge,Xiaoyan Pang,Ruoling Liu,Shuyi Wen,Jiaqi Sun,Weijie Liang,Jianfang Ge,Xunjun Chen
Methoxyl-capped MQ silicone resin (MMQ) was first synthesized by the hydrosilylation of vinyl-containing MQ silicone resin and trimethoxysilane and then used in condensed room-temperature vulcanized (RTV) silicone rubber as a self-reinforced cross-linker. Results show that modified silicone rubber exhibits good light transmission. Compared with unmodified silicone rubber, the hardness, tensile strength and elongation of MMQ at the break are increased by 26.4 A, 2.68 MPa and 65.1%, respectively. In addition, the characteristic temperature of 10% mass loss is delayed from 353.5 °C to 477.1 °C, the temperature at maximum degradation rate is also delayed from 408.9 °C to 528.4 °C and the residual mass left at 800 °C is increased from 1.2% to 27.7%. These improved properties are assigned to the synergistic effect of the rigid structure of MMQ, the formation of a dense cross-linking structure in polymers and the uniform distribution of MMQ cross-linking agent in RTV silicone rubber.Keywords:cross-linker;MQ silicone resin;hydrosilylation;silicone rubber;modified
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Fengyuan Chen,Jie Ma,Zihan Zhong,Hongbin Liu,Aijun Miao,Xiaoshan Zhu,Ke Pan
Marine diatoms are currently facing increasing threats from microplastic (MP) pollution that is intertwined with the disturbed nutrient stoichiometry in seawater. The effects of nutrient imbalances such as silicon (Si) limitation on the interactions between diatoms and MPs remain poorly understood. In contrast to previous studies which mainly focused on MP toxicity, this study emphasizes how Si availability affects nano-scale interactions between pristine polystyrene MPs and diatom surfaces. Results showed that Si-starved cells were less tolerant to MP toxicity than the Si-enriched counterparts. Si limitation significantly changed the configuration and chemical composition of the perforated frustules, forming less negatively charged, more adhesive, and mechanically weaker cells. All of these changes facilitated the adsorption and hetero-aggregation between the diatom cells and MPs and compromised the diatoms’ resistance to MP attack. Our study provides novel insights into the effects of pristine MPs in the marine environment under the context of dynamic nutrient conditions.
研究领域:
海洋生物学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Coatings Technology and Research
·
2020
·Vol. 17
·期 2
·563-572
·
IF 1.815
Li Dan,Xu Feigao
Silicon dioxide coatings modified by (3-aminopropyl)triethoxysilane (ATS) were studied to test their potential use as materials for stone protection. The synthetic route is simple and environmentally friendly due to the lack of volatile organic components. These materials are simply obtained by mixing tetraethylorthosilicate (TEOS), ATS, and OH-terminal polydimethylsiloxane (PDMS-OH). The ATS acts as a curing catalyst and coupling agent. The formulations can be directly applied onto stone substrates, particularly the external stone of buildings. Thus, the goal of an application of silicon dioxide modified by ATS is to restore and to protect building substrates. In the hybrid materials, PDMS acts to form bridges linking the silica particles. Finally, the effectiveness of these products as a stone consolidant and coating was assessed by multiple indicators, including the mechanical resistance, peeling performance, water uptake by capillarity, and contact angle.
研究领域:
材料科学
·
文物保护
✓ 已验证
DOI
高影响因子
POWDER TECHNOLOGY
·
2020
·
IF 4.142
Yang Chen,Xing Wang,Chengji Deng,Chao Yu,Jun Ding,Hongxi Zhu
The Si@SiC@Si 3 N 4 composites with core-shell structure were synthesized by a catalytic nitridation method, Si powder and phenolic resin were used as the raw materials, ferric nitrate was used as the catalyst. The effect of catalyst content on synthetic powders was investigated. The results indicated that when no catalyst was added, a small amount of whiskers were formed on the surface of the Si powder. The addition of the catalyst could effectively promote the formation of SiC and Si 3 N 4 , and a double-layer core-shell structure was formed in which the inner shell is a SiC plate and the outer shell is a Si 3 N 4 whisker. However, excessive addition of the catalyst caused the resulting Si 3 N 4 whiskers to distorted and intertwined. The prepared composite materials (5 wt% catalyst) exhibited good rate capability and a specific capacitance of approximately 200 F/g at 0.5–3 A/g. Finally, the possible formation mechanism of this core-shell structure was proposed.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2015
·Vol. 53
·期 8
·1023-1031
·
IF 3.113
Hua-Feng Fei,Xiyin Gao,Xiaojie Han,Qian Wang,Tao Hu,Zhijie Zhang,Zemin Xie
Novel fluorine containing siloxane monomer, namely, 4-trifluoromethylphenylmethyl cyclosiloxane ( PF3 ) and mixed cyclosiloxane including both 4-trifluoromethylphenylmethyl siloxane ( P ) unit and trifluoropropyl siloxane ( F ) unit were successfully synthesized in this study. Furthermore, their series including vinyl-terminated copolymers with different compositions were synthesized. The microstructures of copolymers were investigated by 1 H NMR, 29 Si NMR, 19 F NMR, Fourier transform infrared spectroscopy, and differential scanning calorimetry (DSC). The results of characterizations confirmed that the copolymers exhibited random microstructure. Moreover, the analysis of the result of DSC also revealed that the copolymers had a low glass transition temperature. The thermogravimetric analysis indicated that poly(4-trifluoromethylphenylmethyl)siloxane ( PPF3 ) exhibited higher thermal stability than conventional fluorosilicones rubber ( FSR ). The dynamic mechanical analysis showed that the damping factors of these copolymers were greater than 0.3 in a wide range of temperature. The mass swelling ratios were less than 5.5% when the samples were immersed in No. 3 jet fuel for a month. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53 , 1023–1031
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2018
·
IF 1.686
Xiguang Liu,Xuejun Cui,Chunxu Zhang,Xiandong Zhang,Guangshun Wu
Effects of different silanization followed via the sol-gel growing of silica nanoparticles (SiO 2 ) onto carbon fibers (CFs) on interfacial strength of silicone resin composites were investigated systematically. CFs were grafted with 3-aminopropyltriethoxysilane (APS) at different conditions to introduce amino groups (CF-NH 2 ) or ethoxy groups (CF-Siloxane) for improving interfacial interaction between CFs and SiO 2 . Experimental results indicated that SiO 2 was grown onto different functionalized CFs successfully, which enhanced the wettability owing to the increases of fiber polarity and surface roughness. Interlaminar shear strength (ILSS) and interfacial shear strength (IFSS) of SiO 2 modified CFs composites enhanced significantly, especially for CF-Siloxane grafted with SiO 2 (CF-Siloxane-SiO 2 ), increasing 46.79% in ILSS and 39.61% in IFSS. Additionally, the introduced Si O C bonds increased hydrothermal aging resistance of the resulting composites greatly.
研究领域:
材料科学
·
复合材料工程
✓ 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）