超分子形状记忆聚合物的合成及应用研究进展

超分子形状记忆聚合物是一种新型的形状记忆聚合物,深受材料科学界人士的重视。本文介绍了超分子形状记忆聚合物的合成方法,并综述了超分子形状记忆聚合物在水凝胶、生物材料等方面的应用研究进展。     

形状记忆功能纤维及纺织品

形状记忆功能纺织品的开发是近年来在纺织材料学中研究较热门的新兴技术。介绍了该材料国内外的研究进展,对形状记忆合金类、形状记忆聚合物类和形状记忆水凝胶类功能纺织品进行了概述;并对各种不同类别的形状记忆功能纺织品的形变机理和适用领域进行了详细阐述,最后展望了形状记忆功能纺织品的未来。     

氨纶增强形状记忆聚合物复合材料

氨纶增强形状记忆聚合物复合材料,它涉及一种形状记忆聚合物复合材料。本发明解决了现有形状记忆聚合物复合材料可回复应变低的问题。形状记忆聚合物复合材料由形状记忆聚合物材料和氨纶组成。本发明的氨纶增强形状记忆聚合物复合材料的可回复应变达到了10％以上,具有较大的可回复应变,再回复时又能够输出较大的外力。     

氨纶增强形状记忆聚合物复合材料

氨纶增强形状记忆聚合物复合材料，它涉及一种形状记忆聚合物复合材料。本发明解决了现有形状记忆聚合物复合材料可回复应变低的问题。形状记忆聚合物复合材料由形状记忆聚合物材料和氨纶组成。本发明的氨纶增强形状记忆聚合物复合材料的可回复应变达到了10％以上，具有较大的可回复应变，再回复时又能够输出较大的外力。     

智能聚合物凝胶的研究进展

智能聚合物凝胶是一种包含大量溶剂但又不溶解的高分子或大分子聚集体,它们具有良好的溶胀性能和三维空间网络结构,又被称为"软材料",具有独特的物理化学性质。广泛应用于药物载体、生物传感、形状记忆材料等领域。本文综述近年来国内外开发的智能响应性凝胶,重点介绍响应性凝胶的结构特征和性能特点。并对响应性聚合物凝胶的发展进行展望。     

热致双向形状记忆聚合物的研究进展

双向形状记忆聚合物是具有双向记忆效应的智能材料。从物理复合和化学合成方法两方面概述了热致双向形状记忆聚合物的制备,从热驱动、磁驱动、电驱动等方面综述了近些年来双向形状记忆聚合物驱动方式的研究进展,并对双向形状记忆聚合物的应用前景进行了展望。     

形状记忆聚合物的发展及应用

介绍形状记忆聚合物的发展历史及最新研究进展，从结构角度分析和探讨了聚合物产生形状记忆效应的原因，并对交联聚烯烃，聚氨酯，聚酯等热致形状记忆聚合物的特性及应用进行了介绍和评价，最后结形状记忆聚合物的发展前景进行了展望。     

形状记忆聚合物研究现状与发展

讨论了形状记忆聚合物的类型和特点．综述了聚氨酯、交联聚乙烯、反式1，4-聚异戊二烯等形状记忆聚合物的研究进展，分析了形状记忆聚合物的形状记忆机理及其应用，并提出了存在的问题。     

磁致形状记忆聚合物的研究进展

综述了磁致形状记忆聚合物的研究进展,包括磁致形状记忆聚乳酸、聚己内酯和聚氨酯等,并介绍了磁致形状记忆聚合物在生物医学工程上的应用,包括在药物缓释中的应用、在矫形外科和骨折固定中的应用和在人体中风治疗方面的应用等,同时展望了磁致形状记忆聚合物的发展前景。     

形状记忆聚合物

综述了形状记忆聚合物的4种基本类型：热致、电致、光致和化学感应型,介绍了热致形状记忆聚合物的记忆机理,概述了聚降冰片烯、反式聚异戊二烯、交联聚乙烯及聚氨酯等形状记忆聚合物研究进展,同时介绍了形状记忆聚合物材料在医疗、包装、建筑、玩具、汽车、报警器材等领域的应用。     

层压制备交联LDPE及其形状记忆性能的研究

采用层压成型的工艺,在低剪切应力下制备了交联低密度聚乙烯(XLPE)。对XLPE进行了凝胶含量、形状记忆性能与拉伸强度的测试。结果表明:当过氧化二异丙苯(DCP)质量分数为1.0%时,凝胶含量接近70%并趋于稳定,形状回复率达到100%,XLPE的拉伸强度提高。说明组合加工方法可显著提高DCP的交联效率,XLPE的形状回复与力学性能有明显的改进。     

聚合物凝胶堵漏剂的研究与应用进展

聚合物凝胶堵漏剂是近年来逐步完善和发展起来的一种堵漏材料。简要介绍了聚合物凝胶堵漏剂特点及作用机理,并对国内外聚合物凝胶堵漏剂的研究及应用进行了评述。聚合物凝胶堵漏剂包括地下交联聚合物凝胶和可吸水膨胀交联聚合物凝胶,交联聚合物凝胶强度较低,必须与其他刚性材料配合才能很好地发挥作用。在堵漏施工中,交联聚合物凝胶不受漏失通道的限制,能够通过挤压变形进入裂缝和孔洞空间,最终达到封堵漏层的目的。现场应用表明,聚合物凝胶堵漏剂与其他材料配合使用,能很好地解决钻井过程中的恶性漏失,堵漏成功率高,对碳酸盐岩、裂缝发育地层及孔洞漏失特别有效。     

Effect of chemical cross-linking under elongation on shape restoring of poly(vinyl alcohol) hydrogel

An anisotropically swollen hydrogel of poly(vinyl alcohol) (PVA) was found to be able to restore an isotropic physical shape by restoring isotropic physical cross-links induced by anisotropically distributed chemical cross-links. The anisotropic chemical cross-links were introduced in the isotropic physical gel by cross-linking with glutaraldehyde under elongation. The physical gel was made from the PVA aqueous solution by repetitive freezing and thawing. The chemically cross-linked gel had kept its original shape and physical properties despite the chemical treatment under strain. However, by the heat treatment in boiling water, the gel changed its form anisotropically depending on the strain applied in the chemical treatment. The anisotropically swollen gel was deswollen in methanol and then reswollen in water. The reswollen gel took back its original isotropic shape, suggesting that the anisotropic chemical cross-links thus introduced in the gel have a memory effect on the restoration of isotropic physical cross-links. © 1992 John Wiley & Sons, Inc.     

Influence of blocked polyisocyanate on thermomechanical, shape memory and biodegradable properties of poly(lactic acid)/poly(ethylene glycol) blends

A series of shape memory biodegradable blends from poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG) were prepared by solution casting method. Ethyl cellosolve-blocked polyisocyanate (EC-bp) was synthesized and used as a cross-linker to obtain cross-linked PLA/PEG blends. The chemical structure of the prepared composite was confirmed by Fourier transform infrared spectra. Thermomechanical, thermal and shape memory properties of the blends were investigated and compared by dynamic mechanical analysis, thermogravimetric analysis and shape memory testing. The results showed that EC-bp cross-linked PLA/PEG blends had better thermal and thermomechanical properties than non-cross-linked blends and displayed good shape memory effects in both shape fixity rate and shape recovery rate. Moreover, the effect of EC-bp addition on the rate of biodegradable degradation in a phosphate buffer solution (pH 7.4) was studied at 37?°C. The prepared cross-linked PLA/PEG blends demonstrated better degradation resistance compared to the non-cross-linked blends.     

Microwave-induced shape-memory poly(vinyl alcohol)/poly(acrylic acid) interpenetrating polymer networks chemically linked to SiC nanoparticles

Microwave (MW)-induced shape-memory poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) interpenetrating polymer networks (SMP-IPNs) were prepared through in situ polymerization. Silicon carbide (SiC) nanoparticles were modified by 3-(methacryloyloxy) propyltrimethoxysilane (KH570). 3-(Methacryloyloxy) propyltrimethoxysilane was covalently bonded on the surface of SiC through the reaction of silanol and the methoxy groups. The polymerization of acrylic acid (AA) using N,N′-methylenebis (2-propenamide) (MBA) as cross-linker in PVA solution was initiated through the double bonds of KH-570 grafted on SiC, leading to a PAA polymer network cross-linked with MBA. The PVA molecular chains run through the PAA cross-linking network and form an IPN structure. Therefore, SiC as a strong MW absorbing material could be chemically cross-linked into polymer matrix. The effect of composition on the properties of SMP-IPN was studied using dynamic mechanical analysis, dielectric properties and shape memory effect (SME) test. The results showed that the introduction of SiC in IPNs not only provided samples with excellent MW-induced shape memory effect (SME), but also caused a higher equilibrium temperature under MW irradiation. Moreover, both SiC content and applied MW power affected the shape recovery properties of PVA/PAA interpenetrating composites. MW-induced SMPs offered great advantages such as fast recovery, high recovery rate, and remote actuation. This study provides the potential applications of the fast and environmentally friendly SMPs used as MW-responsive sensors, implantable devices, etc.     

部分水解聚丙烯酰胺有机交联剂的研制

以部分水解聚丙烯酰胺( HPAM)为主体,添加合成的酚醛树脂水溶液交联,形成的聚合物凝胶体系在不同质最浓度配比下粘度随时间的变化趋势,从而找到最佳的配比条件.结果表明,部分水解聚丙烯酰胺与酚醛树脂最佳的浓度比为2.5∶1,聚合物成胶后体系粘度在3h后达到最大值,胶液粘度稳定后与未交联的胶液相比粘度大为提高.     

High transition temperature shape memory polymers (SMPs) by telechelic oligomer approach

This work describes the synthesis and comparative shape memory properties of cross-linked networks derived from epoxy and cyanate ester monomers containing polyether oligomers as reactive shape memory segments. The hydroxy telechelic oligomers viz. polyethyleneglycol (PEG), polypropyleneglycol (PPG), and polytetramethyleneglycol (PTG) are reacted with epoxy–cyanate ester matrix resulting in shape memory polymers with high transition temperatures. The soft oligomer segments act as flexible linker unit which interconnect oxazolidone, isocyanurate and triazine ring structures in the cross-linked polymer. The resultant cyclomatrix SMPs exhibit high transition temperatures 132, 178 and 161 °C respectively for PEG, PPG and PTG integrated SMPs. The E_g/E_r ratios are increased in the order PEG < PTG < PPG. The PTG and PPG based SMPs show shape retention of 99% and shape recovery of >98% with recovery time <100 s. All the SMPs display good thermal stabilities (both inert and oxidative) above 275 °C.     

Photopolymerized Thiol-Ene Systems as Shape Memory Polymers

In this study we introduce the use of thiol-ene photopolymers as shape memory polymer systems. The thiol-ene polymer networks are compared to a commonly utilized acrylic shape memory polymer and shown to have significantly improved properties for two different thiol-ene based polymer formulations. Using thermomechanical and mechanical analysis, we demonstrate that thiol-ene based shape memory polymer systems have comparable thermomechanical properties while also exhibiting a number of advantageous properties due to the thiol-ene polymerization mechanism which results in the formation of a homogeneous polymer network with low shrinkage stress and negligible oxygen inhibition. The resulting thiol-ene shape memory polymer systems are tough and flexible as compared to the acrylic counterparts. The polymers evaluated in this study were engineered to have a glass transition temperature between 30 and 40 °C, exhibited free strain recovery of greater than 96% and constrained stress recovery of 100%. The thiol-ene polymers exhibited excellent shape fixity and a rapid and distinct shape memory actuation response.     

智能型温敏形状记忆高分子材料的研究进展

综述了热致感应型形状记忆高分子材料的工作原理、形成记忆功能的方法及其分类和应用,介绍了热致感应型形状记忆纤维的生产技术和国内外研究发展状况,并对热致感应型形状记忆高分子材料的未来研究发展趋势作以评述。     

乙烯基对苯二甲酸类甲壳型液晶高分子的形状记忆性能

通过自由基聚合合成了四种基于乙烯基对苯二甲酸类甲壳型液晶高分子（PBPCS,PMPCS,PDCHVT,PbiPCS）。TGA和DMA表征结果表明,这四种甲壳型液晶高分子均具有较好的热稳定性,其侧基末端基团刚性越大,相对应的片材在30～80℃温度区间刚性越大。形状记忆弯角回复测试表明：四种聚合物热压成型的片材都具有很好的形状记忆固定率,均接近100%。形状记忆回复效果与聚合物侧基的末端基团有关,侧基末端基团分别为对丁氧基苯基和环己基（对应聚合物分别为PBPCS和PDCHVT）时,片材显示出较好的形状记忆性能,形状记忆回复率分别为87%和100%。将PDCHVT通过熔融纺丝制成纤维,采用形状记忆循环DMA测试表征其形状记忆性能,结果表明PDCHVT纤维具有稳定的优异的形状记忆性能。