国内外玄武岩纤维耐腐蚀性能对比研究

对国内外玄武岩纤维的耐腐蚀性能进行了研究,并对其腐蚀机理进行了探讨。结果表明:国产玄武岩纤维(TX)在水、酸、碱腐蚀后的质量变化幅度略小于国外同类型产品(KV);去离子水处理后TX的强度保留率为83.57%,KV的则为90.17%;2 mol/L盐酸处理后TX的强度保留率为90.21%,KV的则为89.71%;2 mol/L H2SO4处理后TX的强度保留率为65.66%,KV的则为64.98%;5%Na OH溶液处理后TX的强度保留率为58.14%,KV的则为73.38%;饱和Ca(OH)2溶液处理后TX的强度保留率为87.75%,KV的则为72.67%;酸对玄武岩纤维的腐蚀由外而内逐步进行,碱对玄武岩纤维的腐蚀几乎内外同步进行。     

岩土工程用玄武岩纤维复合材料研究及性能评价

为了提高岩土工程的施工质量，以玄武岩纤维布、酚醛树脂、纳米材料Si-Q和固化剂ER-1为主要原料，制备了一种适用于岩土工程的玄武岩纤维复合材料，并对其拉伸性能、弯曲性能和抗老化性能进行了测试。试验结果表明：纳米材料Si-Q的加入量越大，玄武岩纤维复合材料的拉伸强度越大，而弯曲强度则先减小后增大；此外，玄武岩纤维复合材料还具有良好的耐酸碱老化性能，当纳米材料Si-Q的质量分数为5%时，玄武岩纤维复合材料在盐酸溶液中浸泡80 d后的拉伸强度和弯曲强度分别为337 MPa和252 MPa，与浸泡前相比强度保留率分别可以达到76.59%和80.25%，而在氢氧化钠溶液中浸泡80 d后的拉伸强度和弯曲强度分别为405 MPa和299 MPa，与浸泡前相比强度保留率则分别可以达到92.05%和95.22%。玄武岩纤维复合材料的综合性能较好，能够满足岩土工程施工对加固材料性能的要求。     

聚醚醚酮纤维的发展现状与应用

综述了国内外聚醚醚酮(PEEK)纤维的研究发展现状;分析了制约我国PEEK纤维发展的原因;介绍了PEEK树脂的流变性能、纺丝技术;阐述了PEEK纤维的结构、物理化学性能及应用领域;提出我国应加大PEEK原料及其纤维的研发,实现PEEK纤维国产化。     

日光老化及海水老化对PPTA纤维结构及性能的影响

通过日光老化、海水老化及日光/海水复合老化实验,研究了不同老化方式及老化时间对聚对苯二甲酰对苯二胺(PPTA)纤维表面形貌、化学结构、结晶结构及力学性能的影响。结果表明：随日光老化时间延长,PPTA纤维表面逐渐劣化,分子链中酰胺键发生断裂,结晶度和晶粒尺寸下降,结晶结构被破坏,力学性能呈现先慢后快的下降趋势,日光老化35 d后PPTA纤维的断裂强度和断裂伸长率保留率分别为73.7%和69.2%;海水老化35 d后PPTA纤维表面产生深度较浅的纵向沟壑,大部分集中在纤维皮层;复合老化35 d后PPTA纤维表面纵向沟壑较日光老化35 d时更深,逐渐向PPTA纤维芯层深入;海水老化35 d后纤维的断裂强度和断裂伸长率保留率分别为63.0%和72.4%,日光/海水复合老化35 d后纤维断裂强度和断裂伸长率保留率分别为58.7%和65.9%。     

乙烯基树脂复合材料湿热老化性能研究

本文研究了乙烯基树脂复合材料层合板在80℃湿热老化条件下的老化性能。研究表明,湿热老化42d后,复合材料拉伸强度保留率为60%,弯曲强度保留率为63%,这是由于湿热老化对界面产生的影响造成的;DMA数据表明,复合材料的玻璃化转变温度以及损耗因子都呈现下降的趋势。     

复合成盐剂对聚醚醚酮合成与性能的影响

采用4,4′-二氟二苯甲酮、对苯二酚为原料,以不同比例的碳酸钾和碳酸钠为复合成盐剂,二甲苯为脱水剂,二苯砜为溶剂成功制备了一系列聚醚醚酮(PEEK)树脂。通过傅里叶红外光谱和X射线衍射对PEEK树脂结构进行了表征,证明合成的样品是对苯二酚型PEEK树脂。其次,对所制样品分别进行力学性能、特性黏度、热性能测试,详细地探讨不同钾/钠比例的复合成盐剂对PEEK性能的影响。结果表明,所有样品均展示了优异的力学性能和热性能,其熔点和初始分解温度分别大于330℃和520℃,拉伸强度介于77~101 MPa。此外,当碳酸钾和碳酸钠的物质的量比为7∶3时,PEEK树脂的综合性能达到最优。     

高性能聚醚醚酮/长玻璃纤维复合材料的研制及应用

以长玻璃纤维(GF)和聚醚醚酮(PEEK)为原料,采用挤出造粒的方法制备了高性能PEEK/长GF复合材料,并对其微观形貌、热性能及力学性能进行了研究.结果表明,长GF与PEEK结合紧密,当长GF质量分数为15%时,PEEK/长GF复合材料的热分解温度比纯PEEK提高了55℃,拉伸强度、剪切强度及弯曲强度分别提高了70%、46%和68%.     

PEEK/ZA8复合材料的制备及力学与摩擦学性能研究

采用模压成型法制备了锌铝合金(ZA8)填充聚醚醚酮(PEEK)复合材料,研究了ZA8含量和固体添加剂石墨和聚四氟乙烯(PTFE)对复合材料力学和摩擦学性能的影响。结果表明,复合材料的力学性能随着ZA8含量的增加呈先增加后降低的趋势,冲击强度和拉伸强度在ZA8含量为10%(质量分数,下同)时最大,分别为16.21 kJ/m^2和111.59 MPa,与纯PEEK相比分别增加了10.3%和3.9%;复合材料的摩擦因数随ZA8含量的增加呈持续下降的趋势,在ZA8含量为40%时最低为0.275,与纯PEEK相比降低了38.6%;磨损量呈先减小后增大的趋势,在ZA8含量为10%时最低为7.2 mg,比纯PEEK减小了43.3%;石墨和PTFE的添加能有效减小PEEK/ZA8复合材料的磨损量,其中加入10%的PTFE(未添加石墨)所制得的复合材料的摩擦学性能最好,摩擦因数为0.22、磨损量为4.3 mg,与纯PEEK相比分别降低了50.9%和66.1%。     

PEEK高强耐磨复合材料的制备与性能

采用微型注塑机制备了聚醚醚酮/玻璃纤维/碳纳米管(PEEK/GF/CNTs)复合材料,对PEEK/GF/CNTs复合材料的力学性能、导热性能、摩擦性能进行了研究。结果表明:室温(25℃)下,GF的加入使PEEK材料的拉伸强度提高了43.37%;随着温度的升高,PEEK及其复合材料的拉伸强度逐渐下降;随着CNTs用量的增加,PEEK/GF/CNTs复合材料的拉伸强度呈先增大后减小的趋势;在1 000N的载荷下,PEEK/GF/CNTs复合材料的耐摩擦性能最佳;CNTs的加入提高了PEEK材料的耐热性能;当CNTs质量分数为8%时,PEEK/GF/CNTs复合材料拉伸强度为168.64 MPa,导热系数为0.416 2 W/(m·K),结晶度为16.18%,综合性能最佳。     

抗氧剂对聚乙烯光降解膜结构及性能的影响

采用紫外光加速老化的方法研究了抗氧剂1010对聚乙烯(PE)光降解膜的影响,并通过红外光谱、紫外光谱分析和拉伸性能测试对老化前后的薄膜的结构和性能进行了研究。结果表明,抗氧剂1010能抑制PE的光氧化降解,且导致薄膜光降解过程中羰基化合物的生成量和类型减少;添加抗氧剂1010的光降解薄膜降解的诱导期延长,PE光降解膜紫外照射3 d后其断裂伸长保留率小于80 %,而添加0.3 %（质量分数,下同）抗氧剂1010的PE光降解膜照射4~5 d后其断裂伸长保留率小于80 %。     

脂肪族喷涂聚脲的制备及其桥梁拉索涂层应用性能

采用半预聚法制备了一种新型脂肪族喷涂聚脲,讨论了其耐腐蚀、耐黄变和耐老化等性能.结果表明,该聚脲具有优良的力学性能和耐老化性能,拉伸强度≥20 MP a、断裂伸长率≥400％,人工气候老化1500 h力学性能保持率≥89％,与未老化样片相比△E≤2,臭氧老化1500 h后表面无可见裂纹,且在高密度聚乙烯(HDPE)护套...     

聚醚醚酮纤维的拉伸定形后处理研究

通过熔融纺丝制得聚醚醚酮(PEEK)纤维,并采用差示扫描量热仪(DSC)、声速取向测量仪、热重分析仪、单纱电子强力仪分别研究了干热拉伸及热定形处理对PEEK纤维结晶和取向、热稳定性及力学性能的影响。结果表明:随着热拉伸倍数增大,PEEK纤维取向度、结晶度增加,纤维的断裂强度增加,断裂伸长减小;PEEK纤维的热拉伸温度应选在200～240℃,热定形温度应为220～260℃;PEEK纤维的重结晶主要是在热拉伸过程中完成,热定形则进一步完善纤维的结晶结构;经过后处理,PEEK纤维的断裂强度可达到6.12cN/dtex;且具有优异的热稳定性能,热分解温度高达505℃,后处理几乎不影响PEEK纤维的热稳定性。     

聚醚醚酮核用电缆料拉伸性能测量不确定度评定

选择GUM法对核用电缆料聚醚醚酮(PEEK)薄膜的拉伸强度和断裂拉伸应变,进行测试结果的测量不确定度评定,分别从A类不确定度和B类不确定度进行评定,A类不确定度主要通过重复测试来分析PEEK试样的均匀性产生的测量不确定度,拉伸强度的B类不确定度主要考察了仪器设备引入的测量不确定度,断裂拉伸应变的B类测量不确定度还考察了测试结果的数值修约引入的测量不确定度。结果表明,厚度为1.00 mm的PEEK试样,拉伸速率为20 mm/min,拉伸强度的测试结果为112 MPa,k=2时,测量不确定度为5 MPa;断裂拉伸应变的测试结果为150%,k=2时,测量不确定度为10%。     

The influence of crystallinity on interfacial properties of carbon and SiC two‐fiber/polyetheretherketone (PEEK) composites

The influence of the degree of crystallinity on interfacial properties in carbon and SiC two‐fiber reinforced poly(etheretherketone) (PEEK) composites was investigated by the two‐fiber fragmentation test. This method provides a direct comparison of the same matrix conditions. The tensile strength of the PEEK matrix and the interfacial shear strength (IFSS) of carbon or SiC fiber/PEEK exhibited the maximum values at around 30% crystallinity, and then showed a decline. The tensile modulus increased continuously with an increase in the degree of crystallinity. Spherulite sizes in the PEEK matrix became larger as the cooling time from the crystallization temperature increased. Transcrystallinity of carbon fiber/PEEK was developed easily and more densely than with SiC fiber/PEEK. This might have occurred because the unit cell dimensions of the crystallite in the fiber axis direction on the carbon surface was more suitable for making nucleation sites. The IFSS of carbon fiber/PEEK was significantly higher than that of SiC fiber/PEEK because it formed transcrystallinity of IFSS more favorably.     

含苯炔基侧链的聚酰亚胺树脂及其复合材料

采用联苯酐(3,4′-BPDA)与4,4′-二氨基二苯醚(4,4-ODA),3,5-二氨基-4′-苯炔基二苯甲酮(DPEB),苯炔基苯酐(PEPA)制备了不同分子质量的聚酰亚胺树脂。通过流变分析,热重分析,红外光谱,动态热力学分析及静态力学性能测试等研究了分子结构,分子质量等因素对聚酰亚胺树脂耐热性和力学性能的影响。结果表明,合成的聚酰亚胺树脂具有优异耐热性能和较高的韧性,固化后树脂的玻璃化转变温度为379℃,5%热失重温度高于550℃,并且浇注体的拉伸强度是61 MPa,断裂伸长率是6.2%.碳纤维复合材料的室温弯曲强度为1 850 MPa,层间剪切强度为84 MPa,316℃时弯曲强度为946 MPa,剪切强度为46 MPa,具有良好的高温力学保持率。     

一步法制备聚乙醇酸纤维的工艺及其性能研究

以聚乙醇酸(PGA)为原料,采用熔融纺丝-拉伸-卷绕一步法工艺制备PGA纤维,研究了工艺路线对纤维结构的影响,重点讨论了拉伸倍数对纤维的结构、力学性能、回弹性能及亲水抗静电性能的影响.结果表明:采用熔融纺丝-拉伸-卷绕一步法工艺,可以较好地实现PGA纤维的热拉伸,纤维与纤维之间不易黏结,纤维结构的稳定性得到改善;随着拉...     

Effects of thermal history on mechanical behavior of PEEK and its short-fiber composites

The effect of crystallinity differences induced by mold wall temperature and annealing on mechanical behavior is evaluated for poly(etheretherketone) (PEEK) resin and its composites. The systems investigated were neat PEEK, glass fiber (GF) reinforced PEEK, and carbon fiber (CF) reinforced PEEK. Both composite systems were reinforced with 10, 20, and 30 wt% fiber. The degree of crystallinity (X_c) of PEEK was found to increase by processing at higher mold temperatures, by annealing, and by fiber length reductions, which appears to indicate the ability of short fibers to nucleate the crystallization of PEEK under favorable thermal conditions. Improvements in Young's modulus and strength together with ductility reductions are generally obtained as crystallinity increases in both neat PEEK and its composites. The contribution of crystallinity to mechanical behavior is significant only for neat PEEK and PEEK reinforced by 10% fiber. SEM micrographs reveal that this is due to a change in failure mode. When PEEK is reinforced by carbon fibers or by 20–30% glass fibers, a macroscopic brittle mode of failure is observed irrespective of matrix crystallinity, and mechanical behavior is principally determined by the nature and content of the reinforcing fibers.     

Crystallization of poly(etheretherketone) (PEEK) in carbon fiber composites

The tendency of carbon fiber to nucleate the zation of poly(etherettterlcetone) (PEEK) has been evaluated by DSC and other techniques. As the carbon fiber content was increased, the supercooling necessary for PEEK crystallization decreased. The repeated melting (at 396°C) of the same PEEK sample results in a decrease of the number of nuclei for crystallization. At equivalent thermal histories, PEEK with carbon fiber was found to have a higher nucleation density than PEEK itself. The surface of carbon fibers and nuclei in the PEEK matrix compete for crystallization growth. As the holding time in melt was increased, the number of matrix spherulites formed on cooling decreased, hence a more pronounced transcrystalline region was developed. Correspondingly, the composites preheated in the melt for 100 min showed about two times the transverse tensile strength and strain-to-failure of those preheated for only 30 min. Corresponding fracture surface produced in tension showed that the former samples had a greater matrix adhesion to the carbon fiber than the latter. A strong interfacial bond is thus developed by crystallization on carbon fiber surface. Destroying nuclei in the PEEK matrix by long preheating enhances crystallization on the carbon fiber.     

建筑增强用聚丙烯腈纤维的耐海水腐蚀性研究

模拟混凝土应用的海洋环境,在常温(25℃)、氯化物浓度为5610 mg/L的海水中对建筑增强用聚丙烯腈(PAN)纤维进行浸泡处理,研究建筑增强用PAN纤维的耐海水腐蚀性,并与聚对苯二甲酸乙二醇酯(PET)增强纤维和聚丙烯(PP)增强纤维进行对比。结果表明:海水浸泡50 d后,建筑增强用PAN纤维的主要吸收特征峰无明显变化,且无新的吸收特征峰出现,纤维超分子结构变化较小,晶区取向度基本保持不变,结晶度略有增加;海水浸泡50 d后,建筑增强用PAN纤维的拉伸强度为1261 MPa、降幅0.63%,初始模量为18.6 GPa、增幅8.14%,其拉伸强度与PET增强纤维相当、约为PP增强纤维的1.8倍,初始模量约是PET增强纤维的1.4倍、PP增强纤维的3.2倍;建筑增强用PAN纤维、PET增强纤维、PP增强纤维的拉伸强度耐蚀系数分别为99.4%,99.2%,100.0%,建筑增强用PAN纤维的耐海水腐蚀性介于PP增强纤维和PET增强纤维之间,但其在海水中环境中具有优异的模量保持优势,可以更好地提高混凝土在海水环境中的耐受力。     

Effect of thermotropic liquid crystalline poly(ether ketone)arylates on the processibility and properties of poly(ether ether ketone)s fibers

A series of composite fibers based on poly(ether ether ketone)s (PEEK) and a thermotropic liquid crystalline poly(ether ketone)arylates (PEKAR) have been prepared by melt spinning. The structure, compatibility, and properties of these composite fibers were investigated in detail by rheological measurements, differential scanning calorimetry, thermogravimetric analysis, wide‐angle X‐ray diffraction, scanning electron microscopy, orientation degree test, and mechanical properties test. The results showed that the addition of PEKAR could reduce the apparent melt viscosity of the blends obviously, which is beneficial in improving the processibility of PEEK at a relatively low temperature. After adding 1 wt % PEKAR to PEEK, the tensile strength of the post‐treatment fiber improved by 8.8%, whereas the crystallinity of the as‐spun fiber increased from 21.76% to 31.51%, and the orientation degree also increased with the addition of PEKAR. The result of morphology research suggested that PEKAR had a good compatibility with PEEK resin. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40595.