A series of shape memory polyurethane (SMPU) substrates were fabricated utilizing polyether polyol (PPG) with varying molecular weights, 4,4 '-diphenylmethane diisocyanate (MDI), and4,4 '-methylene-bis-(2-chloroaniline) (MOCA) as primary raw materials. Tetrahydrofuran (THF) served as the solvent. The investigation focused on the effects of different soft segment molecular weights and additional THF content on the properties of SMPU. The study aimed to explore the impact of varying soft segment molecular weights and THF additions on the shape memory properties of polyurethane, as well as the mechanism behind THF's influence. The findings demonstrated that the introduction of THF significantly enhanced the phase separation degree and ordered hydrogen bonding of polyurethane, leading to the acquisition of shape memory properties. Compared to specimens without THF addition, when PPG had a molecular weight of 500, hydrogen bonding increased by 50 %. Furthermore, at THF addition of 9 mL, the specimen exhibited the highest shape recovery degree, with a phase separation temperature of 28.21 degree celsius, a degree of carbonyl-ordered hydrogen bonding of 49.08 %, a bending strength of 43.81 MPa, and an impact toughness of 38.19 KJ/m(2). The shape memory performance of the specimens was evaluated at various temperatures, revealing that the models both achieved 100 % shape fixation at different temperatures. Additionally, the degree and rate of retraction increase with the increase in temperature. The shape memory performance of the prepared specimens was shown to be good by the DMA shape memory cycling test.

Polycarbonate/aluminum alloy hybrids were prepared using a homemade ultrasound-assisted hot pressing molding (UAHPM) technique, and their properties and structures at the plastic-metal interface were also investigated. The aluminum alloy surface was chemically etched and anodized to form micron and nano-holes structures. The joint strength of 21.58 MPa was achieved at the optimum molding process by optimizing the process parameters of ultrasonic hot compression molding. The specific structure and morphology of the polycarbonate/aluminum hybrid material bonding layer were observed by field emission scanning electron microscopy (FE-SEM) using the ultrathin sectioning technique, and the plastic embedding depth reached about 3.8 mu m under the optimal process conditions. X-ray photoelectron spectroscopy (XPS) analysis revealed that the bonding layer not only has a micro-nano interlocking structure but also forms an Al-O-C chemical bonding interaction. The plastic in the bonding layer was exposed by dissolving the aluminum alloy of the joint, and the filling form of the plastic in the micro-nanoholes was directly observed.

针对建筑节能储能材料的应用,采用真空吸附法制备了一系列十八烷含量不同的十八烷/膨胀石墨定形相变材料,通过微观形貌观察、渗漏性能测试、差式扫描量热分析和冷热循环稳定性分析探究膨胀石墨吸附十八烷的最佳含量以及其各项性能.通过分析得出,当十八烷的吸附量为90％(质量分数)时,该吸附含量下的十八烷/膨胀石墨定形相变材料综合性能最佳,其熔融焓和凝固焓值分别为188、186.9 J/g,与国内外不同复合相变材料相比,具有较高的焓值.通过50℃烘箱加热2 h后,也没有明显的十八烷渗出的现象,质量损失率均小于1％,说明其具备了较好的防渗漏性能和结构稳定性.

采用真空吸附法制备了十八烷/膨胀石墨和石蜡/膨胀石墨定形相变材料为前驱体,将其按比例复配得到中低温双阶相变材料,并采用全水发泡一步法制备了中低温双阶相变聚氨酯硬泡材料.通过SEM、DSC、TGA和万能试验机等测试方法对聚氨酯硬泡的泡孔结构、力学性能、相变性能、热稳定性和调温能力进行研究.结果表明,当双阶相变材料为95％时,其熔融焓和结晶焓分别为58.29和53.69 J/g,且在匀速加热和降温的过程中,在26oC和60oC出现了恒温平台,表现出良好的调温控温能力.

Polymer-metal hybrids were prepared by using the ultrasonic-assisted hot-press molding process. The surface of the aluminum alloy is anodized to produce nano-pores with a pore size distribution of 60 to 210 nm. The surface of the anodized aluminum alloy is soaked with a silane coupling agent solution to alter its surface polarity. In addition, PP-g-MAH was used to alter the polarity of polypropylene. The structure and properties of the composites were investigated by tensile shear tests, the microstructure of the bonding interface, and elemental analysis. The results show that adding silane coupling agents can create a chemical connection based on the mechanical interlocking structure of the composite bonding interface, leading to an increase in tensile shear strength. When the aluminum alloy surface was treated with a silane coupling agent with a volume fraction of 4%, the tensile shear strength reached 21.02 MPa, increasing by 20.32% compared to the specimen without the silane coupling agent treatment.

Magnesium alloy/PC/ABS composites were prepared by hot-press molding technology. The bonding strength is the crucial factor to influence the comprehensive performance of this composite, and it was closely related to the different processing parameters such as temperature, pressure and time. After exploring their relationship, the optimal hot-press processing condition was obtained. The micro- and nano-structure of composites also received attention. Before hot-pressed, the magnesium alloy surface was treated by micro-arc oxidation in order to construct the nano-sized pores. With the aid of scanning electron microscope (SEM) and atomic force microscope (AFM), a refined mechanical interlocking structure was observed with the formation of coordinate bonds at the interface of an alloy-polymer hybrid. The binding energy of the chemical elements at the bonding interface of the composite was also tested by X-ray photoelectron spectroscopy (XPS) and the analysis concluded that coordination bonds were formed at the bonding interface. The maximum tensile shear strength of the composite reached 9.48 MPa.

In order to solve the leakage problem of commonly used polyethylene glycol (PEG) phase change material (PCM), PEG reacted with 4' 4-diphenylmethane diisocyanate (MDI) to prepare the polyurethane-based solid-solid phase change material (PU-SSPCM) by the two-step solvent method, and the influence of organic montmorillonite (OMMT) on the phase transition property and crystallization capacity of PU-SSPCM was first studied. The solid solid phase change polyurethane materials were successfully prepared when the molar ratio of PEG to MDI was 0.75, and the organic montmorillonite acted as a crosslinking heterogeneous nucleating agent to improve the temperature control capacity, the crystallization ability and the thermal stability of the solid-solid phase change polyurethane material. When the addition of OMMT was 0.5 wt%, the phase change enthalpy of PU-SSPCM increased to 106.8J/g from 95.46J/g, a constant temperature platform appeared for about 300 s during both the heating and cooling process, thus demonstrating excellent temperature control ability. The relative crystallinity increased to 74.8% from 66.5% and the initial thermal weight loss temperature was increased from 348 degrees C to 368 degrees C.

相变储能材料作为新型材料在建筑节能、生态可持续等方面有着不可替代的优势和应用价值.由于固液相变材料易泄露问题在一定程度上限制了固液相变复合材料的推广应用.围绕中低温固液相变材料的封装技术,介绍了中低温相变潜热储热材料及其相变封装技术的研究现状,重点概述了硅藻土、膨胀蛭石和膨胀珍珠岩等多孔矿物基吸附相变材料,膨胀石墨为主的多孔碳基相变复合材料,以及气凝胶相变复合材料的制备技术,对相变复合材料在相变材料负载能力、相变热性能、导热性能进行了介绍.在此基础上,提出了固液相变复合材料未来研究工作方向,以期为固液相变材料的应用和推广提供一定的借鉴.

提高聚氨酯耐热性能是聚氨酯应用研究热点.文章以聚醚多元醇(PPG)、4,4'—二苯基甲烷二异氰酸酯(MDI)、3,3—二氯—4,4—二氨基二苯基甲烷(MOCA)为主要原料,采用预聚体法制备聚氨酯(PU),探讨了扩链系数对聚氨酯耐热性能的影响.结果表明,随着扩链系数的增加,聚氨酯的综合力学性能、耐热性能先升高后降低,动态机械分析(DMA)显示,增加扩链系数使得PU玻璃化转变温度(Tg)的内耗峰向高温方向移动.当扩链系数为0.04时,聚氨酯力学性能最佳,拉伸强度为64.16 MPa,弯曲强度为84.69 MPa,冲击韧性为8.88 kJ/m2,阻尼因子最大值(Tanδmax)为1.108,热分解初始温度达到315℃.