期刊：
Progress in Organic Coatings,2019年127:408-418 ISSN：0300-9440
通讯作者：
Li, Xiangzhou
作者机构：
[Liu, Yanxin; Zhou, Jun; Li, Xiangzhou; Wu, Zhiping; Qian, Wei] Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Qian, Wei] Guangdong Polytech Environm Protect Engn, Nanhai 528216, Foshan, Peoples R China.;[Li, Xiangzhou] State Key Lab Ecol Appl Technol Forest Area South, Changsha 410004, Hunan, Peoples R China.;[Liu, Yanxin] Changsha Univ Sci & Technol, Sch Chem & Bioengn, Changsha 410114, Hunan, Peoples R China.
通讯机构：
[Li, Xiangzhou] C;Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
关键词：
Tea saponin;CTS-IFRCs;Synergistic effects;Multi-stage gas phase flame-retardant mechanism;Pyrolysis kinetic performance
摘要：
Tea saponin intumescent flame-retardant coatings (TS-IFRCs) is a green and high-efficiency flame-retardant coating based on natural-based tea saponin (TS), and has been confirmed with superior flame retardancy. The present study determined and assessed the effects of TS on the flame-retardant mechanism in composite tea saponin intumescent flame-retardant coatings (CTS-IFRCs) through the analysis of TG-DSC, FT-IR, SEM-EDS and pyrolysis kinetics. It has been demonstrated from the results that TS, synergized with other components in CTS-IFRCs, has direct and significant impacts on the char layer microstructure, flame retardancy and pyrolysis performance, these influences contributed to the double effects of TS as a blowing agent in gas phase flame-retardant mechanism, and as a carbon agent in condensed phase flame-retardant mechanism. High synergistic effects of natural-based TS revealed in this study have provided effective theoretical basis for emerging environmentally friendly bio-based flame-retardant materials and explored a new way for the utilization of TS.
作者机构：
[刘德乡; 刘武; 叶志会; 吴志平] School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha;410004, China;[刘德乡; 刘武; 叶志会; 吴志平] 410004, China
通讯机构：
School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, China
关键词：
生物质;温敏性;智能材料;自由基聚合
摘要：
温敏材料是重要的智能材料之一。虽然温敏均聚物具有良好的环境敏感性能,但其力学性能无法满足使用要求,且部分温敏均聚物的最低临界溶解温度(Lower critical solution temperature,LCST)难以改变,从而限制了其应用领域。当温敏聚合物与其他基材复合或接枝共聚时,可以有效提升温敏材料的力学性能,同时通过改变物料组成及配比可以调节温敏材料的临界温度,拓展其应用范围。制备温敏智能材料的原料大多来源于不可再生的石油资源,随着石油资源日渐匮乏,人们逐渐将目光转移到其他资源。生物质作为可再生资源,广泛存在于自然界中,具有资源丰富、可持续利用的优点,特别是其含有羟基、胺基、醚键和羧基等活性官能团,可以提供多种活性位点,与温敏单体接枝共聚来制备温敏材料,是一种很好的温敏材料基材。已成功应用在生物质温敏智能材料中的生物质原料包括纤维素、纤维素醚、半纤维素、木质素、壳聚糖等。然而,制备生物质基温敏智能材料的接枝共聚方法单一,传统的自由基共聚制备的温敏材料存在温度响应范围窄、产生温敏均聚物较多且难分离以及制备的材料形态单一等问题。生物质温敏材料的接枝共聚方法已经从最初的以引发剂引发的普通自由基聚合发展到可控性较强的光引发自由基聚合、原子转移自由基聚合(Atom transfer radical polymerization,ATRP) 、单电子转移活性自由基聚合(Single election transfer living radical polymerization,SET-LRP) 、可逆加成-断裂链转移法(Reversible addition-fragmentation chain transfer,RAFT)等接枝共聚方法。温敏接枝单体较多,其中研究最多的为N-异丙基丙烯酰胺(N-isopropylacrylamide,NIPAM),其具有明确的临界溶解温度,且最低临界溶解温度与人体温度相差不大,它与生物质材料一起制备的温敏性膜、温敏性水凝胶和温敏性微球等在药物释放、组织工程和工农业等方面具有广泛的应用。本文详细归纳了生物质大分子制备温敏材料的方法,对这些接枝共聚方法的特点进行总结,同时介绍了制备温敏材料涉及的温敏物质、温度响应机理以及生物质基温敏智能材料的应用,最后总结了现阶段生物质基温敏智能材料制备及应用中存在的难点,并对未来的技术发展进行了展望。
摘要：
Cellulose nanocrystal (CNC)/poly(lactic acid) (PLA) in situ nanocomposite scaffolds were fabricated by in situ polymerization of lactic acid and CNC which was directly utilized as aqueous suspension, followed by a process of thermally induced phase separation. The CNC/PLA in situ nanocomposite porous scaffolds were characterized by mechanical test, protein adsorption, hemolysis test, in vitro degradation measurement, TEM, FTIR, SEM and WAXD. Compared to the PLA scaffold, the CNC/PLA in situ nanocomposite scaffolds showed a greatly increased compression modulus, an improved hemocompatibility and protein adsorption capacity. The inclusion of CNCs boosted the in vitro degradation of the in situ nanocomposite porous scaffolds and facilitated the deposition of Ca2+, CO32- PO43- ions in simulated body fluid. Furthermore, cell cultures were carried out on the CNC/PLA in situ nanocomposite porous scaffolds. In comparison with the PLA scaffold, the in situ nanocomposite scaffolds improved cell attachment and enhanced cell proliferation, denoting low cytotoxicity and good cytocompatibility. It can therefore be concluded that such scaffolds with excellent mechanical property, biocompatibility, biomineralization capacity and bioactivity hold great potential for bone tissue engineering. (C) 2019 Elsevier B.V. All rights reserved.
作者机构：
[袁彩霞; 罗卫华; 袁光明; 吴志平; 周钢; 杨素文] College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha;410004, China;[袁彩霞; 罗卫华; 袁光明; 吴志平; 周钢; 杨素文] 410004, China
通讯机构：
[Luo, W.] C;College of Material Science and Engineering, China
摘要：
In this paper, silane coupling agent and organic modified bentonite were used in tea saponin intumescent flame-retardant coatings to improve the flowability, storage stability and film properties. The effects of silane coupling agent and organic modified bentonite on the flowability, storage stability and film properties were discussed, and flame resistance and pyrolysis performance of the flame-retardant coatings also were investigated. The results show that silane coupling agent can greatly improve the rheological properties, storage stability and film properties of the flame-retardant coating at the amount of 1.5%. Flame-retardant coatings have good dispersion properties and thixotropy, When bentonite modified with cetyltrimethylammonium chloride (CTAC-Bentonite) was introduced to the coatings. Fire resistance test and TG-DTG analysis showed that silane coupling agent/organic bentonite can promote the charring of the coatings and increase the amount of char, which protecting the internal substrates, reducing the thermal degradation rate. What's more, the flame retardancy of the materials was improved significantly owing to the increasing of the amount of residual carbon and the enhancing of thermal stability at a high temperature.
作者：
Wu, Zhiping*;Hu, Na;Wu, Yiqiang;Wu, Shuyun;Qin, Zu
期刊：
Journal of Nanomaterials,2014年2014:1-8 ISSN：1687-4110
通讯作者：
Wu, Zhiping
作者机构：
[Wu, Yiqiang; Hu, Na; Wu, Zhiping; Qin, Zu; Wu, Shuyun] Cent South Univ Forestry & Technol, Sch Mat Sci Engn, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Wu, Zhiping] C;Cent South Univ Forestry & Technol, Sch Mat Sci Engn, Changsha 410004, Hunan, Peoples R China.
摘要：
The effect of ultrafine magnesium hydroxide (UMH) and ordinary magnesium hydroxide (OMH) on the tensile properties and flame retardancy of wood plastic composites (WPC) were investigated by tensile test, oxygen index tester, cone calorimeter test, and thermogravimetric analysis. The results showed that ultrafine magnesium hydroxide possesses strengthening and toughening effect of WPC. Scanning electron micrograph (SEM) of fracture section of samples provided the positive evidence that the tensile properties of UMH/WPC are superior to that of WPC and OMH/WPC. The limited oxygen index (LOI) and cone calorimeter test illustrated that ultrafine magnesium hydroxide has stronger flame retardancy and smoke suppression effect of WPC compared to that of ordinary magnesium hydroxide. The results of thermogravimetric analysis implied that ultrafine magnesium hydroxide can improve the char structure which plays an important role in reducing the degradation speed of the inner matrix during combustion process and increases the char residue at high temperature.
作者机构：
[李文生; 吴志平; 李湘洲; 钱伟] College of Material Science and Engineering, Central South Univ of Forest and Technology, Changsha, Hunan 410004, China;[房丛丛] Business School, Central South Univ of Forest and Technology, Changsha, Hunan 410004, China;[李文生] College of Chemistry and Chemical Engineering, Hunan Univ, Changsha, Hunan 410082, China;[李湘洲] State Engineering Laboratory of Ecological Applied Technology in Forest Area of South China, Changsha, Hunan 410004, China
通讯机构：
College of Material Science and Engineering, Central South Univ of Forest and Technology, China
