可膨胀石墨的合成及其阻燃应用

可膨胀石墨是一种重要的化合物，广泛用于各种科学和生活领域，作为阻燃剂，它是一种高效无毒阻燃剂， 通过中断反应，中断热传导等起阻燃作用。本文主要讨论可膨胀石墨（Epandable graphitd)的特性，制备及其聚乙烯阻燃方面的应用，并用氧指数，热分析方法对可膨胀石墨阻燃塑料的阻燃，热分散行为进行研究。     

可膨胀石墨在阻燃材料中的应用

本文综述了可膨胀石墨的组成，性质及其在阻燃材料中的应用，并把它和传统膨胀阻燃体系进行了比较。     

膨胀石墨聚磷酸铵复合阻燃聚丙烯初探

以国产膨胀石墨为主阻燃剂，聚磷酸铵为协效剂，讨论了膨胀石墨复合阻燃剂两组分不同配比对阻燃聚丙烯燃烧性能和力学性能的影响。当膨胀石墨复合阻燃剂用量为30份、石墨与聚磷酸铵比为2：1时，材料的氧指数为21.7，拉伸强度为32，4MPa，缺口冲击强度为0.51KJ／m^2，力学性能和阻燃性能指标较好，材料的综合性能最佳，复合阻燃剂两组分在此配比时具有明显的协同效应。阻燃剂用量超过30份后。材料的拉伸强度快速下降，失去使用价值。     

可膨胀石墨阻燃水发泡聚氨酯泡沫塑料的制备

采用四溴醇合成了适合水发泡的阻燃聚醚多元醇,并通过可膨胀石墨与其它阻燃剂的复配使用,制得了可膨胀石墨阻燃的水发泡聚氨酯泡沫塑料。讨论了溴代醇种类、发泡剂种类及用量、可膨胀石墨粒径及用量和复合阻燃剂配比等因素对泡沫阻燃性能的影响。结果表明,该阻燃聚醚多元醇与含有可膨胀石墨的复合阻燃剂复配使用,制得的可膨胀石墨阻燃水发泡聚氨酯泡沫塑料氧指数可达33%,压缩强度为280KPa,达到了国家标准GB/T8624-1997中B1级氧指数的要求,并且阻燃剂用量少,阻燃效果稳定。     

可膨胀石墨协同阻燃的研究进展

可膨胀石墨(EG)是一种良好的环保型阻燃剂,但单独使用时阻燃能力仍显不足,利用阻燃剂之间的协同阻燃作用能够大幅提高EG的阻燃效果.根据与EG起协同作用的阻燃剂的种类不同,把EG的协同阻燃分为磷系协同阻燃体系、膨胀型阻燃剂(IFR)协同阻燃体系、氢氧化镁协同阻燃体系以及其他阻燃剂协同阻燃体系4类,介绍了不同协同阻燃体系的阻燃性能和阻燃机理的研究进展,并展望了EG协同阻燃的发展趋势和应用前景.     

不同粒径可膨胀石墨无卤阻燃高密度硬质聚氨酯泡沫塑料研究

采用高速混合破碎机对可膨胀石墨（EG）进行处理，制得不同粒径的EG。考察了不同粒径EG填充的硬质聚氨酯泡沫塑料（RPUF）的微观形态，研究了EG对于RPUF燃烧行为的影响。结果表明：EG的粒径越小，其在聚氨酯体系中的分散就越困难；20％未经处理的EG粒子（EGO）填充的RPUF氧指数为39．5％，比未填充的RPUF氧指数提高了近一倍，而经过13min破碎的EG粒子（EG13）其氧指数仅为23．5％，     

聚脲材料包覆可膨胀石墨微胶囊阻燃天然橡胶

以聚脲材料为壳材包覆可膨胀石墨(EG),并在囊壁上嵌入CuO提高壁材的导热性能,从而获得可膨胀石墨微胶囊(EG@PO),然后将制备的EG@PO与聚磷酸铵(APP)复合应用于阻燃天然橡胶(NR).通过SEM、热失重和红外光谱分析等手段对EG@PO进行表征.通过极限氧指数、垂直燃烧测试、热失重测试、锥形量热仪和导热系数测定...     

可膨胀石墨对环氧树脂的阻燃改性

本文利用环氧树脂E-51和固化剂聚醚胺WHR-H023(质量比为3∶1)制成树脂基体。采用H_2SO_4和HNO_3对颗粒尺寸为80目的可膨胀石墨进行表面酸化处理,制备亲水性酸化可膨胀石墨;并将酸化处理的可膨胀石墨及未经酸化处理的可膨胀石墨分别对上述树脂基体进行阻燃改性,石墨添加量为5%、10%和15%。借助红外光谱分析仪检测酸化处理的可膨胀石墨表面羧基、羟基等官能团的接枝情况;利用极限氧指数分析仪和万能材料试验机分别测试改性树脂基体材料的极限氧指数(LOI)及拉伸性能;采用扫描电子显微镜(SEM)观察改性树脂基体材料的断面。研究结果表明,酸化可膨胀石墨比未经酸化处理的可膨胀石墨对环氧树脂基体的阻燃效果更佳,且拉伸性能下降更少。     

制备低硫可膨胀石墨的研究

研究了以过二硫酸铵作氧化剂低硫可膨胀石墨的制备，找到了在较低温度下，制备低硫可膨胀石墨的最佳条件。即过二硫酸铵和石墨的重量比为１５％；反应温度为５５℃；反应时间为４０ｍｉｎ；硫酸浓度为９８％；硫酸与石墨的重量比为４∶１，草酸和硝酸（浓度为６５％）的重量比为７．５％时，所制得的可膨胀石墨含硫量为０．６５％，膨胀容积为２００ｍＬ／ｇ可膨胀石墨。并且，其终端产品柔性石墨具有优良的力学性能和抗氧化性能。     

爆轰裂解可膨胀石墨制备石墨微粉

在不改变石墨原始结构与成分的基础上,利用冲击波对可膨胀石墨进行爆轰,收集爆轰灰,进行X射线衍射、SEM的测量分析以及BET法测定比表面积。结果表明,可膨胀石墨经过爆轰后,得到了颗粒大小为1μm～10μm的石墨粉,比表面积由8.096m^2/g增大至47.48m^2/g,并且孔隙变得更为均匀,常规研磨设备是无法达到这种效果的。为石墨的细化提供了一种更为简便快捷而又节省能源的方法。     

Preparation of a novel type of flame retardant diatomite and its application in silicone rubber composites

A novel strategy was used for preparation of flame retardant based on biomass debris to improve the flame retardant property of silicone rubber (SR). [(6-oxido-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl)methyl]butanedioic acid (DDP) was used to modify diatomite by esterification method, and DDP@diatomite was obtained. The structure and morphology of this novel additive was identified using Fourier transform infrared spectroscopy (FTIR), Brunner-Emmet-Teller (BET) measurements, and X-ray photoelectron spectroscopy (XPS) together with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS) techniques. Thermogravimetric (TG) analysis was performed to evaluate the thermal degradation behaviors of diatomite and DDP@diatomite. This novel additive was applied into silicone rubber (SR) composites. Combustion parameters, including heat release rate (HRR), total heat release (THR), smoke production rate (SPR), carbon monoxide (CO), peak smoke production rate (PSPR), peak carbon monoxide (PCO) and vertical burning time, were characterized by cone calorimeter and vertical burning tests. Results indicated that this flame retardant can reduce fire risk and toxicity effectively. TG and X-ray diffraction (XRD) patterns of SR and its composites were also investigated. The inexpensive property of modified diatomite could also expand its fire safe applications.     

阻燃剂聚磷酸铵对脱醇型RTV-1硅橡胶性能的影响

采用α,ω-二羟基聚二甲基硅氧烷(107胶)、气相白炭黑、无机阻燃剂聚磷酸铵(APP)等制备了无机阻燃脱醇型单组分室温硫化(RTV-1)硅橡胶,研究了APP用量对脱醇型RTV-1硅橡胶阻燃、物理性能和贮存期的影响,以及APP阻燃脱醇型RTV-1硅橡胶的热稳定性.结果表明,当APP的用量达80份以上时,脱醇型RTV-1硅橡胶才具有阻燃性能.但随着APP用量的增加,脱醇型RTV-1硅橡胶的拉伸强度、扯断伸长率均逐渐下降;当加入80份APP时,脱醇型RTV-1硅橡胶贮存期为9个月以上,APP几乎不影响其贮存的性能.添加了80份APP的阻燃脱醇型RTV-1硅橡胶与未加APP的脱醇型RTV-1硅橡胶相比,初始分解温度下降.     

改性蒙脱土硅橡胶阻燃复合材料的制备

研究了分别采用十六烷基三甲基溴化铵(CTAB)和磷酸三丁酯作为插层剂改性的有机蒙脱土(OMMT)的阻燃效果及抑制熔滴物产生的效果,发现单独添加OMMT的硅橡胶阻燃复合材料都有抑制熔滴物产生,减少烟和灰尘生成的作用,但是不具备阻燃的效果;将OMMT与100份Al(OH)3和40份Fe2O3进行复配,发现只需添加3份的有机蒙脱土一(OMMT-1)或5份有机蒙脱土二(OMMT-2)即可达到垂直燃烧FV-0级别;热重分析表明,OMMT的热稳定性能比蒙脱土原土好,OMMT-1的比OMMT-2的好。     

复配无卤阻燃聚氨酯泡沫塑料的制备与表征

通过添加N,N’-二(2-硫代-5,5-二甲基-1,3,2-二氧磷杂环己基)乙二胺(DDPSN)、三聚氰胺(MA)、聚磷酸铵(APP)单组份阻燃剂及其复配阻燃剂,制得无卤阻燃聚氨酯泡沫塑料,并对其阻燃性能、力学性能、密度、吸水率以及热性能等进行了研究。研究结果表明,单组份阻燃剂中DDPSN阻燃效果较好,复配阻燃体系中,DDPSN与MA以及DDPSN与APP均具有良好的协同阻燃效果,其中DDPSN与APP协同效果最好。拉伸测试表明,单组份阻燃剂中APP表现较好,DDPSN/APP复配对聚氨酯泡沫的力学性能提高较大。DDPSN/APP复配阻燃体系对聚氨酯泡沫塑料的表观密度和孔结构影响不大,但使泡沫塑料的降解温度提高。     

Preparation and characterization of nano-hydroxyapatite/silicone rubber composite

To take advantage of the merits for both hydroxyapatite (HA) and silicone rubber (SR) in medical applications, we developed a novel method to produce a new nano-composite of these two widely used biomaterials. In this work, n-HA (nano-hydroxyapatite) slurry, which was modified by silane coupling agent, was mixed with silicone gum and the nano-composite could therefore be achieved. It is found that the dispersion states of the n-HA particles in SR are homogeneous and the mechanical properties of the composite can be improved significantly. The composites with micrometer HA (μ-HA) and SR were taken as the contrast for comparison. We find that the tensile strength of the n-HA/SR composite can be enhanced greatly in comparison with that of the μ-HA/SR composite.     

Preparation and characterization of the intumescent fire retardant coating with a new flame retardant

In this study the applicability of the new flame retardant for the intumescent fire retardant coating (IFRC) daubed on the top of the plywood was investigated. The following are the three kinds of flame retardants used in this study: (1) the artificial mesophase graphite powder (MGP), (2) the sericite (Al₄(OH)₄(KAlSi₃O₁₀)₂), and (3) the graphite/sericite mixture. The desirable sizes of MGP and sericite were obtained by sieving, and then the surfaces of MGP and sericite were modified using a mechanofusion system. The MGP and sericite were characterized using a scanning electron microscope (SEM), a particle size analyzer, and an energy dispersive spectrum (EDS). The IFRC, which consisted of 19.8% of the flame retardant, 15% of the dehydrate agent, 18% of the foaming agent, 7.2% of the resin binder, and 40% of the solvent, was prepared and daubed on the top of the plywood. The test of the fire protection of IFRC was conducted using a flammability 45° tester. The IFRC with the flame retardant of the raw MGP (or sericite) was also prepared to study the effects of the size distribution and the configuration of the flame retardant on the capability of fire protection of IFRC. The mass ratio of MGP to sericite also substantially affects the capability of fire protection of IFRC. Most interestingly, the capability of the fire protection of IFRC with the flame retardant of the raw material is better than that of IFRC with the flame retardant of the sieved and surface-modified material.     

Mechanical properties, fire performance and thermal stability of magnesium hydroxide sulfate hydrate whiskers flame retardant silicone rubber

Halogen-free flame retardant silicone rubber (SR) composites, using magnesium hydroxide sulfate hydrate (MHSH) whiskers as flame retardant have been prepared by a two-roll mill. Moreover, microencapsulated red phosphorus (MRP) was used as a synergist. Mechanical tests were performed to determine the tensile strength, elongation at break, and shore hardness of the composites. The morphology of fracture surface was observed by environmental scanning electron microscopy (ESEM). The results showed MHSH slightly reduced the tensile strength of the composites, but had obvious influence on the elongation at break. Meanwhile, Shore A hardness presented uptrend with increasing MHSH content. The addition of vinyl silicone fluid (VSF) could improve the compatibility of the MHSH whiskers in SR matrix, and therefore improved the mechanical properties of composites. The flammability properties of composites were investigated by limited oxygen index (LOI), UL-94 tests, and cone calorimetry experiments. It is found that MHSH whiskers can effectively improve the flame retardancy of SR composites due to the endothermic degradation of MHSH whiskers accompanied with the release of water vapor, and the formation of fibrous magnesia acting as a barrier layer. The incorporation of MRP in SR/MHSH whiskers system had a synergic fire retardant effect in the condensed and gas phase. In addition, thermogravimetric analysis (TGA) indicated the presence of MRP enhanced thermal stability of the SR/MHSH composites at higher temperature range, and remarkably promoted char residue yield.     

双层结构纳米羟基磷灰石/硅橡胶复合材料的制备及性能

纳米羟基磷灰石/硅橡胶与硅橡胶在同时硫化的条件下制备出了双层结构的纳米羟基磷灰石/硅橡胶复合材料,利用XRD、SEM、MTT和力学性能测试等手段对复合材料进行表征.结果表明,两层材料的界面结合紧密,材料的细胞相容性好,力学性能与硅橡胶的力学性能相近,能够达到医用植入硅橡胶材料的要求.     

短玻璃纤维/硅橡胶发泡复合材料的制备及表征

表面改性的短玻璃纤维和硅橡胶共混发泡制备出短玻璃纤维/硅橡胶发泡复合材料,对其力学性能、热性能和结构进行测试。结果表明:当加入长为6mm的短纤维3g(7.5份)时,复合材料的拉伸强度增加155%,达到0.78MPa。沿着纤维取向上的拉伸强度相对于垂直纤维横向增加130%,断后伸长率增加790%;热稳定性提高;结构测试表明复合材料的泡孔孔径平均为0.3mm,呈闭孔且分布稀少,泡孔绕纤维生成;扫描电镜(SEM)显示处理后的纤维与硅橡胶界面处相容性提高。