耐候LLDPE地膜的性能分析

根据西北地区气候差异和膜下滴灌的特点,研制碳酸钙母粒填充体系,以母粒分散光稳定剂和抗氧剂制成线性低密度聚乙烯(LLDPE)超薄地膜,该地膜具有长期环境稳定性、更高的热学与力学性能及性能保留率。当碳酸钙含量5.04%,防老化母粒含量2.1%,通过加工工艺参数优化,所得地膜的拉伸强度提高7.7%,96h抗老化性能保留率大于70%,很好地满足地区特殊气候的使用要求。     

装甲装备橡胶密封件抗老化封存膜的研制

针对东南沿海地区装甲装备橡胶器材老化现象,为了进一步提高涂层本身的防老化性能、改进涂层的施工、减少对环境的污染和尽量降低成本以及防老化涂料的通用性,研究了一种新型的水性橡胶防老化涂料,为我军解决装甲装备橡胶制品老化问题提供新的思路。     

铝合金阳极化氟碳保护涂料的研究

现有阳极化保护涂料普遍存在耐酸性和弹性差的缺点,为此,采用丙烯酸含氟单体、丙烯酸单体、丁苯橡胶(SBS)通过自由基共聚的方法合成了氟碳树脂,获得了一种耐酸、高弹的铝合金阳极化涂料.对树脂的红外光谱分析表明,丙烯酸含氟单体参与了共聚反应.通过原位共聚的方法引入了纳米二氧化钛.随着氟含量的提高,涂层的耐甲乙酮擦拭性、耐酸性、耐沸水附着力、耐人工老化等性能提高,当氟含量超过6%时涂层的附着力下降;纳米TiO2的引入使涂层的耐盐雾性、抗拉强度明显提高;当固体含量为25%,msbs/m单体=4%时,丁苯橡胶的引入,涂层在柔韧性、伸长率、耐磨性、冲击强度方面均有所提高.氟碳丙烯酸保护涂料能够满足铝合金阳极化绝缘保护的要求.     

不同种类混凝土涂料的性能测试及对比研究

混凝土结构中大量使用涂料进行防腐蚀和劣化修复,准确掌握涂料的各项性能对于监控其使用效果十分重要.为了能够快速检验和测试混凝土涂料性能的优劣,根据日本土木协会和日本道路协会标准,检测了分别以氟树脂、聚氨酯和环氧为面漆的涂层配套体系的耐碱性、附着强度、耐老化能力和对裂缝的追随性.对各种涂层的性能进行了对比和分析.结果表明,各类涂层均对混凝土底材具有优异的附着能力;耐碱性能具有较大差异;氟树脂涂层具有更好的耐老化能力和更优的裂缝追随性,对混凝土结构的防护效果最佳.     

火焰喷涂尼龙/纳米TiO2复合涂层性能的研究

为了探讨纳米TiO2对火焰喷涂尼龙1010涂层力学及抗老化性能的影响,利用电子拉力机对火焰喷涂尼龙1010/纳米TiO2复合涂层的力学性能及耐老化性能进行了测试.结果表明,当复合涂层配比为m(PA1010):m(n-TiO2)=100.0:0.5时,复合涂层综合性能较佳,涂层自拉伸强度为43.10 MPa,涂层与基体结合强度为40.23 MPa;涂层经240 h紫外线老化后,强度保持率分别为97.0%和87.2%.纳米TiO2能够显著提高涂层力学性能和抗老化性能.     

POSS杂化环氧丙烯酸树脂的合成及应用

通过自由基聚合的方式将POSS嫁接在环氧丙烯酸树脂链段中，制备出一种POSS杂化的环氧丙烯酸树脂（POSS-co-APA），研究了不同POSS用量对杂化树脂热稳定性能的影响；将POSS-co-APA作为改性剂添加到环氧树脂E51体系中制备复合涂层（PED），探讨了不同POSS-co-APA改性剂添加量对复合涂层性能的影响。结果表明，当POSS质量分数为3%时，POSS-co-APA热稳定性能最优；当改性剂质量分数为5%时，改性环氧涂层硬度最大为6H，断裂伸长率最大为5.2%；当改性剂质量分数为7%时，改性环氧涂层疏水性能最优，疏水角可达110°。     

甲基丙烯酰氧基倍半硅氧烷改性碳纤维/聚芳基乙炔复合材料界面性能

利用微脱粘法、三点弯曲法、扫描电镜（SEM）、力调制模式原子力显微镜（AFM）和动态力学热分析（DMTA）研究了甲基丙烯酰氧基倍半硅氧烷（Methacryl-POSS）涂层改性前后的碳纤维增强的聚芳基乙炔（PAA）复合材料的界面性能。用Wilhelmy法研究了处理前后的碳纤维与PAA树脂的浸润性。结果表明: POSS涂层处理后的碳纤维表面粗糙度增大,与PAA树脂的浸润性提高;复合材料的界面剪切强度提高了36%,层间剪切强度提高了50%。DMTA图谱表明, POSS涂层改性后,复合材料的玻璃化转变温度提高了12℃,损耗因子降低了53%,表明复合材料的界面粘接性能得到大幅度的改善。      

SiO2气凝胶对复合隔热涂料性能的影响

以SiO2气凝胶为功能填料,丙烯酸树脂为成膜剂,制备透明隔热涂料。将其涂覆于5mm厚的普通玻璃上制成涂层,并对涂层进行一系列性能测试,包括接触角、红外光谱、光学性能及隔热效果等。结合实验数据分析纳米SiO2含量对复合涂料性能的影响,得出最佳的涂料配方。结果表明,该透明隔热涂料具有良好的化学稳定性和隔热性能,在500W红外灯照射10min时,样品与空白玻璃温差为11℃。     

新型水性环氧富锌涂料的制备及性能研究

为了满足重防腐蚀领域对涂料耐久性的需要,通过调节环氧富锌涂料中锌粉的比例、添加硅烷偶联剂、优化涂料防沉体系,制备了耐腐蚀性能强、储存稳定性高的水性环氧富锌底漆.研究了该涂料中锌粉、偶联剂、防沉剂3种组分对涂层耐腐蚀性能、附着力及储存稳定性的影响,并将该涂层与环氧中间漆、水性聚氨酯防腐蚀面漆组成了复合涂层体系,分析测试了复合涂层体系的耐中性盐雾腐蚀性能及附着力.结果表明:制备水性环氧富锌底漆的过程中,控制有机膨润土和亲油性气相二氧化硅的含量可提高涂料的储存稳定性,其中锌粉加入量为55.0％(质量分数,下同),防沉剂有机膨润土和气相二氧化硅含量分别为0.8％和1.0％时,涂料的储存稳定性可达10级;硅烷偶联剂加入量为1.5％时,涂层与基体间的结合强度可达到11.3 MPa;该涂料作为底漆与环氧中间漆、水性聚氨酯面漆组成的复合涂层体系,在经过3 600 h中性盐雾试验后不剥落,可用于重防腐蚀领域.     

三乙烯二胺交联季铵化聚芳醚砜电解质膜的制备与性能

采用聚芳醚砜为原料,经付克氯甲基化反应,以三乙烯二胺为交联剂,通过非均相和均相2种季铵化方式制备了2类燃料电池用交联型阴离子交换膜CQPAES。所制备CQPAES膜的离子交换容量为1. 15～1. 25 mmol/g。与非交联膜相比,交联膜的耐溶剂性、尺寸稳定性均得到了提高,在高温高压水中的水解稳定性、强碱条件下的化学稳定性显著增强。季铵化方式对交联膜性能影响的研究表明,均相季铵化膜与非均相季铵化膜相比,可更好地控制交联膜的溶胀,相应交联膜的离子电导率更高。交联剂加入量为0. 1～0. 2时,交联膜的综合性能最佳。     

One-pot strategy for covalent construction of POSS-modified silane layer on carbon fiber to enhance interfacial properties and anti-hydrothermal aging behaviors of PPBES composites

In this study, we describe a novel strategy to design and construct POSS-modified silane layer on carbon fiber (CF) to strengthen the interfacial adhesion and anti-hydrothermal aging behaviors of CF-reinforced copoly(phthalazinone ether sulfone)s (PPBES). POSS was first modified by 3-aminopropyltriethoxysilane (APS) to improve chemical reactivity. Without separation and purification, APS-c-POSS was used to functionalize CF to improve reactivity and ensure the covalent linkages between CF and POSS-modified silane layer. CF coated with POSS-modified silane layer was obtained by in situ hydrolysis of APS-c-POSS. FTIR and XPS confirmed the chemical bonds between CF and POSS-modified silane layer. Dynamic contact angle, dynamic wetting test and AFM tests demonstrated that POSS-modified silane coating can increase the wettability and roughness, which could improve interlaminar shear strength and flexural strength of CF/PPBES composites by 17.5 and 30.0% with slight enhancement on tensile strength of CF. The failure mechanisms of CF/PPBES composites with and without POSS-modified silane layer were both investigated by SEM in detail. Moreover, this layer was helpful to dynamic mechanical property and hydrothermal resistance of CF/PPBES composites. This study provides alternate strategy to modify CF with POSS, which will significantly broaden the application field of POSS in advanced composites.     

芳纶表面改性及其与丁腈橡胶复合材料的性能研究

为增强对位芳纶纤维(PPTA)与丁腈橡胶(NBR)之间的界面粘结强度,采用多巴胺(DA)-硅烷偶联剂对芳纶纤维联合改性并制备PPTA/NBR复合材料。结果表明,纤维改性后表面粗糙度增加;表面元素含量和种类都发生较大变化;在H试样抽出测试中,改性后的PPTA帘线/NBR试样抽出力相对于未改性试样增大64.02%,且黏附橡胶较多。改性后的PPTA/NBR试样,纤维含量相同时,断裂伸长率和拉伸强度相对未改性的PPTA/NBR试样增大;随着纤维含量的增加,使用同种方法处理的PPTA/NBR复合材料断裂伸长率减小,拉伸强度先增大后减小。     

Interfacial properties and impact toughness of methylphenylsilicone resin composites by chemically grafting POSS and tetraethylenepentamine onto carbon fibers

Octaglycidyl polyhedral oligomeric silsesquioxane (gly-POSS) was successfully grafted on carbon fibers (CFs) surface to enhance interfacial properties and impact toughness of CFs reinforced methylphenylsilicone resin (MPSR) composites. After gly-POSS modification, POSS grafted CF (CF-POSS) with many epoxy functional groups was modified with tetraethylenepentamine (TEPA) to further enhance the interfacial strength. Atomic force microscopy (AFM) images showed that POSS and TEPA were grafted onto CFs surface uniformly and the surface roughness enhanced obviously. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed the chemical bonding nature between CFs and POSS, as well as between POSS and TEPA. POSS and TEPA modification could increase the fiber polarity, wettability and surface energy significantly. The interlaminar shear strength (ILSS) and impact toughness of composites showed a dramatic improvement, especially for grafting with POSS and further with TEPA (CF-POSS-TEPA). Additionally, the reinforcing and toughening mechanisms were also analyzed. Meanwhile, single fiber tensile strength (TS) had no decrease after modification.     

粉末NBR-PVC共混型热塑性弹性体断裂面的分形维数

本文利用扫描电镜对粉末NBR-PVC共混型热塑性弹性体拉伸断面形貌进行了观察与分析;基于断面小岛周长-面积关系,测定了试样的断口分形维数,考察了NBR含量、拉伸断面分形维数、力学性能(拉伸强度、断裂伸长率、邵氏硬度)之间的关系。结果表明,NBR-PVC弹性体拉伸断面的分形维数随着NBR含量的增加而增加,当NBR含量超过29份后其分形维数呈下降趋势;分形维数与材料的拉伸强度、断裂伸长率和邵氏硬度变化关系一致。     

乙烯基侧链环氧树脂对E-51/NBR体系的影响

采用新型乙烯基侧链环氧树脂(VE)与E-51环氧树脂/液体丁腈橡胶体系共混,用万能材料试验机、动态力学分析仪和扫描电镜表征了VE的含量对树脂/橡胶体系力学性能、玻璃化转变温度(Tg)、微观相态结构的影响.结果表明,利用VE与E-51、丁腈橡胶良好的相容性可以显著改善树脂/橡胶体系的相容性;添加了VE后,用液体丁腈橡胶改性过的环氧树脂韧性提高,并保持了较好的力学强度;当VE/E-51=4/6,NBR含量为20%(wt)时,其拉伸强度比纯E-51/NBR体系提高11.9%,弯曲强度提高31.3%,断裂伸长率提高14.8%;体系的Tg、微观相态结构都随VE的含量呈现出有规律的变化.     

NBR/PVC橡塑合金辐射防护材料的制备及性能研究

为了满足辐射防护的要求以及发展结构功能一体化柔性防护材料的需求,研制了一种新型的橡塑合金复合防护材料。通过力学性能和屏蔽性能测试发现,该复合材料具有较高的拉伸强度与断裂伸长率,且材料的中子与伽马屏蔽性能良好,随着功能填料含量的不断增加,中子和伽马屏蔽性能也不断提升,但材料的拉伸强度和断裂伸长率不断减小。辐照实验显示,电子束硫化后的样品比硫磺硫化后的样品拥有更出色的力学性能。综合考虑该材料良好的中子与伽马屏蔽性能、拉伸性能与柔韧性能等特性,其在形状较为复杂的核动力设施以及辐射防护服等领域具有较大的应用潜力。     

高能电子束辐照对NBR/PVC胶圈胶料性能的影响

采用高能电子束对丁腈橡胶/聚氯乙烯(NBR/PVC)胶圈胶料进行辐照,研究不同辐照剂量对NBR/PVC胶圈胶料性能的影响。实验结果表明,生橡胶经高能电子束辐照后,焦烧时间随辐照剂量增大逐渐减小;NBR/PVC硫化胶经高能电子束辐照后,冲击弹性提高33%~67%,硬度提高4%~10%,拉伸强度提高8%左右,断裂伸长率下降6.7%~34.4%。单因素试验结果显示,50k~60kGy剂量辐照时,硫化胶拉伸强度提高幅度较大,压缩、拉伸永久变形和磨耗量下降,同时弹性、硬度均有提升。综合考虑,50k~60kGy剂量为辐照NBR/PVC胶圈硫化胶的最适剂量。     

Study on mechanical properties of nano-Fe3O4 reinforced nitrile butadiene rubber

In this study, we used nano-Fe₃O₄ particles as modified filler to prepare NBR/nano-Fe₃O₄ composites. With adding different mass fraction of nano-Fe₃O₄, mechanical properties such as tensile strength, modulus at 300% elongation, shore A hardness, surface microstructure, magnetic character and tribological properties such as friction and wear performance of the NBR/nano-Fe₃O₄ composites were investigated. The anti-wear and friction-reducing properties were also discussed. The results indicated that there was little change on mechanical properties, but the tribological properties were greatly improved, which laid both theoretical and applied foundation for the design of high-performance lubricating composites used for sealing.     

Enhanced mechanical properties of multiscale carbon fiber/epoxy composites by fiber surface treatment with graphene oxide/polyhedral oligomeric silsesquioxane

Graphene oxide (GO) and polyhedral oligomeric silsesquioxane (POSS) grafted carbon fiber (CF) was demonstrated to reinforce the mechanical properties of fiber composites. Such a fiber composite was prepared by grafting POSS onto the CF surface using GO as the linkage. The presence of GO linkage and POSS could significantly enhance both the area and wettability of fiber surface, leading to an increase in the interfacial strength between fibers and resin. Compared with the desized CF composites, the grafted CF composites fabricated by compression molding method exhibited 53.05% enhancement in the interlaminar shear strength. The changed surface morphology, surface composition and surface energy were supposed to be related with the interfacial performance of unidirectional composites, as revealed by scanning electron microscopy, atomic force microscope, dynamic contact angle test and X-ray photoelectron microscopy charaterizations.