环氧树脂灌封胶增韧研究

研究了橡胶、纳米填料对环氧树脂灌封胶的增韧作用。通过加入端羟基丁腈橡胶(HTBN)、聚硫橡胶、纳米氧化铝等,使灌封胶冲击、压缩强度得到了较大提高。     

单体浇铸尼龙的增韧改性研究

以氢氧化钠为催化剂,N-乙酰基己内酰胺为活化剂,在绝热条件下用己内酰胺与十二内酰胺活化阴离子共聚制得改性单体浇铸尼龙共聚体。偏光显微镜观察发现：共聚导致制品无定形区域增多,限制了球晶的生长。测试表明：制品的机械性能与十二内酰胺单体的用量有关,随着十二内酰胺含量的增加制品的缺口冲击强度增强,韧性也得到显著改善。     

超支化环氧化合物的合成与应用

概述超支化环氧化合物的基本概念、结构及性能特点,介绍超支化环氧化合物的合成方法及途经,并对超支化环氧化合物在环氧树脂改性及环氧树脂基复合材料中的应用研究进行了综述,对其未来的发展方向进行了展望。     

EPDM-g-MAH对PPO/PA6共混体系结构与性能的影响

通过双螺杆熔融反应挤出,获得了马来酸酐化的三元乙丙橡胶(EPDM-g-MAH),并将其与聚苯醚(PPO)、尼龙6(PA 6)共混,制备了PPO/PA 6/EPDM三元共混合金。研究了弹性体EPDM-g-MAH中MAH用量以及EPDM-g-MAH用量对PPO/PA 6共混体系力学性能和相态结构的影响。结果表明:EPDM-g-MAH中MAH用量在1%~2%范围内,可显著改善EPDM与PPO/PA 6共混体系的相容性,大大提高共混合金的韧性;在三元共混体系中,随着弹性体EPDM-g-MAH用量的增加,冲击强度和断裂伸长率提高,但拉伸强度降低。     

Excellent Mechanical and Transparency Properties of Cationic Waterborne Polyurethane Films Modified by Boehmite Sol

The strategies for nanosol from metal alkoxide have enabled production of ultratransparent and mechanically robust polymer nanocomposites at extremely high loading. Herein, a simple approach to fabricate high‐performance polyurethane‐based nanocomposites via unmodified boehmite nanoparticles is reported. Evaluating their physical properties, the uniform dispersion of boehmite in the matrix caused nanocomposites retains ultrahigh transparency. Hydrogen bonding and intermolecular entanglement between boehmite and polyurethane brings about the mechanical properties of the nanocomposites material enhanced, i.e., strength, stiffness, and toughness. Optimized strength, stiffness, and toughness of Boehmite/Cationic waterborne polyurethane at 40 wt% (BNC40) are up to 58.1 MPa, 1096.7 MPa, 249.5 MJ m^?3, respectively. Furthermore, the feasibility and mechanism of polymer strengthening and toughening by inorganic rigid nanoparticles is explored from the aspects of crystallinity and micromorphology.     

Ultrafine porous boron nitride nanofiber-toughened WC composites

Porous fibers are widely used in catalysis chemistry and hydrogen storage but are rarely used in structural ceramics. In this study, spark plasma sintering was used to prepare an ultrafine porous boron nitride nanofiber-toughened WC composite for the first time. The obtained WC-0.05 wt% ultrafine porous boron nitride nanofiber composites exhibited better properties (ie, a 2.3% increase in hardness and a 19.6% increase in fracture toughness) compared to those of the pure WC specimen. The fiber porosity improved the second phase-WC matrix microstructural combination. The described approach is a novel preparation method for the WC composites. Furthermore, a new toughening mechanism, which is based on “pinning and stretching”, was determined. These findings suggest that porous boron nitride fibers can be considered to be second phases for toughening the WC composites.     

聚烯烃弹性体增韧共聚聚丙烯的研究

采用拉力试验机、差示扫描量热仪及扫描电子显微镜等仪器,对比分析了不同种类聚烯烃弹性体(POE)产品对共聚聚丙烯(PP)的增韧效果。结果表明:POE的添加对PP具有明显的增韧效果,且随着其添加量的增加,增韧效果越加显著;自制的中试产品的增韧效果达到进口产品Engage 8540水平。     

聚丙烯的共混改性研究

聚丙烯作为一种重要的通用塑料,其拉伸强度和冲击强度较低,限制了其在工程中的应用。聚丙烯的改性已成为使其工程化、功能化的重要手段。综述了聚丙烯共混增韧改性的研究,并介绍了共混改性技术的最新进展。     

纤维对水泥基复合材料性能影响研究进展

为拓宽纤维材料在水泥基复合材料上的应用,促进超高韧性纤维增强水泥基复合材料的发展,对目前国内外纤维性能对水泥基复合材料性能影响的研究进展进行综述。首先,介绍了纤维增强混凝土的种类及增强增韧机制,认为纤维桥接作用可阻止裂纹产生和扩展,显著提高混凝土的拉伸强度和延展性能。其次,分析了混凝土领域常用有机纤维和无机纤维的性能特征;然后对影响纤维增强混凝土性能的因素进行归纳与总结,从混杂纤维、纤维形态、体积分数、纤维排列方向以及纤维粘结性能对复合材料性能的影响关系进行分析。最后,指出纤维增强混凝土研究中亟待解决的问题,并展望了未来纤维增强混凝土的发展趋势。     

环氧树脂增韧增强改性研究进展

综述了国内环氧树脂增韧增强改性的最新研究进展,详细介绍了纳米粒子、液体橡胶、热塑性树脂、原位聚合物、液晶聚合物、核壳聚合物、大分子固化剂和膨胀型单体增韧增强环氧树脂的一些重要研究现状。对它们的增韧增强环氧树脂的优缺点和机理进行了探讨。