磷氮阻燃固化剂对环氧树脂阻燃性能的影响

为了提高环氧树脂固化体系的阻燃性能,以1,3-丙二胺(DPAN)和苯膦酰二氯(PPDC)为主要原料合成一种新型磷氮反应型阻燃固化剂(PPDPA),对合成化合物的组织结构和热性能进行了表征.以不同比例PPDPA为固化剂,制备一系列具有不同磷含量的阻燃环氧树脂,并对其进行热性能分析和阻燃性能测试.结果表明,添加PPDPA的环氧树脂体系的500 ℃残炭明显高于EP/DPAN体系,且残炭表面磷碳层具有明显的发泡现象.当磷的质量分数达到2.12%时,EP-2样品成功通过UL94 V-0阻燃等级测试,LOI值达到28.3%,PPDPA在环氧树脂材料中表现出了良好的阻燃性能.     

Synthesis,characterization and flame-retardant properties of epoxy resins and AACHH composites

Flame retardant epoxy resins were prepared by a simple mixed method using ammonium aluminum carbonate hydroxy hydrate (AACHH) as a halogen-free flame retardant. The prepared samples were characterized by X-ray diffraction, thermogravimetric and differential scanning calorimetry, scanning electron microscope and limiting oxygen index(LOI) experiments. Effects of AACHH content on LOI of epoxy resins/AACHH composite and flame retardant mechanism were investigated and discussed. Results show that AACHH exhibites excellent flame-retardant properties in epoxy resin(EP). When the content of AACHH was 47.4%, the LOI of EP reached 32.2%. Moreover, the initial and terminal decomposition temperature of EP increased by 48°C and 40 °C, respectively. The flame retarded mechanism of AACHH is due to the synergic flame retardant effects of diluting, cooling, decomposition resisting and obstructing.     

HIPS/OMMT复合材料在不同燃烧模式下的阻燃特性

采用熔融插层法制备了高抗冲聚苯乙烯/有机蒙脱土(HIPS/OMMT)复合材料,分别用锥形量热仪、氧指数和UL-94 3种方法测试表征材料的阻燃特性。结果表明,锥形量热仪试验表征材料阻燃特性,得到有机蒙脱土对材料阻燃性较好,而在氧指数法和UL-94测试方法下有机蒙脱土对材料阻燃性较差。分析表明,不同测试方法所对应的燃烧模式不同,由于不同燃烧模式的影响,材料的阻燃机理发生不同作用,导致材料阻燃特性表征结果不同。根据插层复合材料的阻燃机理,结合不同燃烧模式下炭渣的热失重分析,讨论了材料的特殊结构与燃烧条件的相互作用,解释了表征结果差别与燃烧条件的关系。     

水镁石/硼酸锌复合阻燃环氧树脂的制备与性能

针对环氧树脂在添加普通水镁石阻燃剂后力学性能恶化的问题,通过对水镁石的改性和复配制备了一种新型阻燃剂.通过SEM观察水镁石粉体及阻燃环氧树脂断面的表面形貌,利用弯曲强度测试考察阻燃环氧树脂的力学性能,测定氧指数考察其阻燃性能.结果表明,水镁石用量为30%时阻燃EP性能最好.用硅烷偶联剂Ⅰ和Z6173改性,阻燃EP的弯曲强度和氧指数分别为5.21 M Pa、28.9%和4.82 M Pa、29.1%.用6份的硼酸锌与硅烷偶联剂Ⅰ改性的水镁石复配制得的复合阻燃剂,其制备成的阻燃EP的弯曲强度和氧指数最高达到4.85 MPa和29.3%.     

氧化锌与膨胀型阻燃剂对聚丙烯的协效阻燃

采用磷酸、季戊四醇和三聚氰胺为原料合成了一种新型膨胀型阻燃剂(IFR)。并以IFR为阻燃剂,氧化锌(ZnO)为协效阻燃剂,聚丙烯(PP)为基体树脂制备了膨胀型阻燃PP复合材料,重点研究ZnO与IFR之间的协效阻燃作用。采用氧指数测定仪、UL-94测定仪和锥形量热仪等手段研究阻燃PP复合材料的燃烧性能,用动态傅里叶变换红外光谱(FTIR)研究阻燃PP复合材料在不同温度下凝聚相的结构变化,初步揭示其热降解特性。实验结果表明:ZnO与IFR之间存在明显的协效阻燃效果;复合材料在240～330℃时,结构变化最剧烈;ZnO添加质量分数为1.6%时,炭层完整性最好,热释放速率峰值最低,降低幅度可达80%,UL-94为V-0级;ZnO添加质量分数为3.2%时,氧指数(LOI)最大为25.6%,UL-94为V-0级。     

无卤环保型阻燃环氧树脂的研究进展

综述了目前国内外无卤阻燃环氧树脂(EP)的研究发展状况,重点介绍了磷、氮、硅等阻燃元素对EP的阻燃处理及其有关的阻燃机理和存在的一些问题,如相容性差、耐热性不好和添加量受限等,并介绍了相应的解决方法;最后,对无卤阻燃EP的发展趋势进行了展望,并为国内相关企业提出了一条绿色、高效、复合的发展道路.     

PHBV/PBAT复合阻燃材料的燃烧性能、 力学性能及流变性能研究

采用熔融共混的方法,将MMT和聚磷酸铵基阻燃剂添加到PHBV/PBAT复合材料中,研究复合阻燃材料的力学性能、流变性能以及燃烧性能。极限氧指数和垂直燃烧结果表明,聚磷酸铵基阻燃剂的添加提高了复合材料的极限氧指数,MMT的加入使得极限氧指数进一步提高,当MMT的质量分数为1%时通过了UL-94垂直燃烧V-0级别测试。结合流变性能测试与力学性能测试表明,聚磷酸铵基阻燃剂恶化了复合材料的力学性能,而MMT提高了粉体在基体材料中的分散性能,提高了复合阻燃材料的力学性能。锥形量热测试表明,MMT的加入明显降低了复合材料的热释放速率以及产烟量。     

环氧树脂改性聚乙烯材料的研究

用熔融共混方法,将环氧树脂和马来酸酐引入到聚乙烯（PE）中,制备出环氧树脂增强聚乙烯材料。力学性能测试表明,与纯聚乙烯相比,环氧树脂增强聚乙烯材料的弯曲强度有较大提高。红外光谱分析表明,在熔融共混制备环氧树脂增强聚乙烯材料的过程中,环氧树脂与马来酸酐接枝PE发生了官能团之间的反应,促进环氧树脂对PE的增强效果。形态分析表明,聚乙烯中加入环氧树脂和其它助剂后,材料的内部形态结构发生了改变。     

Structural characteristics and properties of PU-modified TDE-85/MeTHPA epoxy resin

Diglycidyl-4,5-epoxycyclohexane-1,2-dicarboxylate (TDE-85)/methyl tetrahydro-phthalic anhydride (MeTHPA) epoxy resin was modified by polyurethane(PU), and its structural characteristics and properties were studied by infrared spectrum analysis (IR), scanning electronic microscopy (SEM), mechanics testing and thermogravimetric analysis (TG). The results indicate that epoxy polymeric network I and polyurethane polymeric network II are formed in the PU-modified TDE-85/MeTHPA epoxy resin. Meanwhile the PU-modified TDE-85/MeTHPA resins have heterogeneous structure. The miscibility between epoxy (EP) and polyurethane (PU) as well as the phase size are dominantly determined by the mass fraction of polyurethane prepolymer (PUP) in the EP/PU blends. With the increase of PUP mass fraction, the tensile strength, impact strength and thermal stability of the PU-modified TDE-85/MeTHPA epoxy resin all firstly exhibit increasing tendency, and decrease after successively reaching their maxima. When the number-average molecular mass of PPG is 1 000 and the mass fraction of PUP is 15%, the tensile strength, impact strength and thermal stability of materials obtained, compared with TDE-85/MeTHPA epoxy resin, are improved obviously.     

无卤阻燃增韧尼龙1313/POE/MCA复合材料的研究

以马来酸酐功能化的乙烯/辛烯共聚物(POE-g-MA)为弹性体,三聚氰胺氰尿酸盐(MCA)为阻燃剂,在SHJ-36双螺杆挤出机中制备了无卤阻燃增韧尼龙1313/POE/MCA复合材料.测定了无卤阻燃尼龙1313/POE/MCA复合材料的极限氧指数(LO I),用扫描电镜(SEM)观察了经锥形量热仪燃烧的该复合材料残炭的形貌.实验结果表明,当POE-g-MA,MCA的质量分数分别为15%和12%时,复合材料的LO I为32%,垂直燃烧通过UL94V-0级,缺口冲击强度是纯尼龙1313的5.5倍,实现了在不使用卤元素阻燃剂并且保证尼龙1313/POE/MCA复合材料力学性能的前提下,大幅度提高该材料阻燃性能的要求.     

Damping properties of fly ash/epoxy composites

An inexpensive fly ash (FA), which is from a waste product, was employed to prepare fly ash/epoxy composites. The purpose of this study is to characterize the contributions of matrix viscoelasticity, hollow structure characteristic (porosity), and filler/matrix interface friction to the high vibration damping capacity of such composites. The damping properties of the composites were investigated in the temperature range of -40 to 150°C and in the frequency range of 10 to 800 Hz by using a tension-compression mode. The results indicate that the peak value of damping loss factor (tanδ) for the fly ash/epoxy composites can reach 0.70-0.90 in test specification, and the attenuation of damping loss factor is inconspicuous with increasing frequency. In addition, scanning electron microscope (SEM) was used to observe the morphology of the fly ash as well as its distribution in the matrix, which will help to analyze the effect of fly ash on the damping properties of the fly ash/epoxy composites.     

Flame retardancy and its mechanism of polymers flame retarded by DBDPE/Sb2O3

The flammability characterization and thermal composition of polymers flame retarded by decabromodiphenylethane （DBDPE） and antimony trioxide （Sb2O3） were studied by cone calorimeter and thermogravimetry （TG）. The results show that ABS/DBDPE/Sb2O3 has the similar flammability parameters and thermal composition curves to ABS/DBDPO/Sb2O3. It suggests that DBDPE/Sb2O3 has the similar flame retardant behavior to DBDPO/Sb2O3. The heat release rate （HRR） and the effect heat combustion （EHC） curves of polymers flame retarded by DBDPE/Sb2O3 all decrease, but the mass loss rate （MLR） curve slightly increase. It shows that the decrease of HRR is not due to the increase of char formation ratio but the generation of incombustible gases. The major flame retardant mechanism of DBDPE/Sb2O3 is gas phase flame retardant mechanism. Increasing content of Sb2O3 in DBDPE/Sb2O3 can improve the flame retardant property and thermal stability of acrylonitrile butadiene styrene. Sb2O3 has a good synergistic effect with DBDPE.     

Influence of surface state on moisture sensitivity of carbon fiber and its composite interfacial properties

The influence of surface state on the moisture sensitivity of carbon fiber was analyzed by applying a T800 grade carbon fiber with five different surface conditions, namely, with and without surface oxidation, in the presence or absence of sizing agent. The interfacial properties of their composites in the presence of two epoxy matrices (respectively EP07 and EP10) were also characterized by micro-droplet tests. The overall results show that both oxidized and sizing-coated fibers have higher moisture equilibrium content than that of the pristine unsurface-treated fiber, due to higher amount of activated carbon groups. After moisture absorption of the carbon fibers, almost all the fiber/epoxy systems show decrease in the interfacial shear strength and the unsurface-treated fiber system exhibits the largest decline. Moreover, both interfacial shear strength and interlaminar shear strength of carbon fiber/EP10 composite demonstrate better water resistance performance than that of the carbon fiber/EP07 composite, consistent with DSC results of the two resins.     

HIPS插层复合材料的结构与阻燃性的关系

根据蒙脱土(MMT)特殊的片层结构,采用熔融插层法制备了HIPS/MMT及HIPS/OMMT复合材料,并用锥形量热仪对材料的燃烧性能进行测试。结果表明,材料中蒙脱土片层的取向影响材料的阻燃性;与竖直取向的HIPS/OMMT复合材料相比,水平取向的HIPS/OMMT复合材料有更低的热释放速率和质量损失速率,具有较高的阻燃性。用扫描电镜表征了不同取向材料燃烧后炭层的形貌,表明形成的炭层也具有横、竖取向。此现象解释了插层复合材料的取向影响材料的阻燃性,为聚合物/层状硅酸盐纳米复合材料阻燃机理的研究提供了依据。     

Surface functionalized carbon nanofibers and their effect on the dispersion and tribological property of epoxy nanocomposites

Surface functionalization of carbon nanofibers (CNFs) was carried out, i e, CNFs were firstly oxidized and then the surface was silanized by 3-Aminopropyltriethoxysilane (APTES) via an assembly method. A new kind of high wear resistance s-CNFs/epoxy composite was fabricated by in-situ reaction. FTIR spectroscopy was used to detect the changes of the functional groups produced by silane on the surface of CNFs. The tribological properties and microstructures of modified and unmodified CNFs/epoxy composites were studied, respectively. The expremental results indicate that APTES is covalently linked to the surface of CNFs successfully and improves the dispersion of CNF in epoxy matrix. The friction coefficients and the wear rates of s-CNFs/epoxy composites are evidently lower than those of u-CNFs/epoxy composites under the same loads. Investigations also indicate that abrasive wear is the main wear mechanism for u-CNFs/epoxy composite, with slight adhesive wear for s-CNFs/epoxy composite under the same sliding wear condition.     

玄武岩纤维布增强环氧树脂复合材料研究

以玄武岩纤维平纹布 (BF) 加入到环氧树脂 (EP) 中,采用模压工艺制备BF／EP 复合材料,研究加入不同层数的玄武岩纤维布对复合材料力学性能和断裂韧性的影响。实验结果表明,BF/EP复合材料的弯曲强度、冲击强度和断裂韧性明显优于环氧树脂;与未加BF的环氧树脂相比,加入三层BF后复合材料的弯曲强度提高了2.76倍,缺口冲击强度提高了19.67倍,无缺口冲击强度提高了5.94倍,KIC提高了2.97倍。     

高折射率环氧树脂的研究进展

高折射率环氧光学树脂设计制备方法主要包括三类:通过有机或无机化合物在环氧光学树脂中引入硫、卤素等高折光指数原子;在环氧光学树脂中引入芳环等高折光指数化学基团;由两种或两种以上的环氧树脂混合固化来制备复合型环氧光学树脂.现有的环氧光学树脂具有收缩率低、化学性质稳定、尺寸稳定性高等优点,但耐候性差,在紫外光的照射下会发黄降解,韧性差而易断裂,硬度不佳在树脂表面易产生划痕等缺点制约了其在更先进领域的应用.制约环氧光学树脂发展的主要因素为材料结构与性能之间的关系不够明确,制备方法不够经济环保以及过于关注材料的折光指数而对其他性能研究较少.进一步明确材料结构与性能之间的关系,在保证高折射率的前提下,平衡材料的其他光学和力学性能是未来研究的重点.     

有机硅改性环氧树脂制备及热稳定性

采用二苯基硅二醇与双酚A型环氧树脂(E-44)反应,制备有机硅环氧树脂及其固化物.通过正交和单因素实验研究原料物质的量比、反应温度和时间对树脂热稳定性的影响,用热机械分析仪、热失重分析仪、傅立叶变换红外光谱仪和化学滴定分析等对改性树脂进行表征.结果表明,用二苯基硅二醇改性E-44,在催化剂为二丁基二月桂酸锡,二苯基硅二醇与E-44物质的量比1∶4,反应温度110℃,反应时间2h时,得综合热稳定性能优异的有机硅改性环氧树脂,较未改性环氧树脂,其热膨胀系数下降33.2％,内应力参数下降36.3％,初始热分解温度提高15℃,而玻璃化转变温度无明显降低,有良好的热稳定性.     

EVA插层复合材料的取向结构对阻燃性能的影响

利用蒙脱土(MMT)特殊的片层结构,采用挤出工艺、熔融插层法制备了乙烯醋酸乙烯脂/蒙脱土(EVA/MMT)和乙烯醋酸乙烯脂/有机蒙脱土(EVA/OMMT)纳米复合材料,用锥形量热仪测试并分析了材料的燃烧性能。结果表明,添加OMMT的复合材料具有阻燃作用;复合材料中蒙脱土片层的(横、纵)取向影响材料的阻燃性;横向取向的EVA/OMMT复合材料有更低的热释放速率和质量损失速率,具有较好的阻燃性。通过扫描电镜(SEM)表征不同取向材料燃烧后炭渣的形貌,表明形成的炭层也为横、纵取向,解释了插层复合材料的横、纵取向对材料阻燃性的影响。     

Damping properties of flexible epoxy resin

Amino-terminated polyethers and amino-terminated polyurethane were used as curing agent to cure the epoxy resin together and get a series of cured products. The damping properties of the composites were studied by DMA test at different measurement frequencies. Damping mechanical tests show that the flexible epoxy resin has higher loss factor than common epoxy. The highest loss factor reaches 1.57. Also the height and position of loss factor peak of the flexible epoxy resin varies by changing the content of amino-terminated polyethers. Results shows that the flexible epoxy resin can be used as damping polymer materials at room temperature or in common frequency range.