PMMA/PnBA乳胶IPN阻尼及转变行为的研究EI

用乳液聚合方法合成了聚甲基丙烯酸甲酯和聚丙烯酸丁酯的互穿聚合物网络(IPN)。动态力学分析结果表明:这种半相容的PMMA/PnBA乳胶IPN在-50°～+60℃温度范围内具有良好的阻尼性能,组成和交联剂用量影响该体系的相容性和阻尼性能。     

一种新型的粘弹性振动阻尼材料——互穿聚合物网络(IPN)

本文总结了前人对互穿聚合物网络(IPN)的研究成果。结合我们的研究工作,着重讨论了IPN的微观形态结构、IPN中各组分相容性和IPN的阻尼性能。指出IPN的形成过程是以热力学因素为主导的相分离过程和以动力学因素为主导的互穿过程相互竞争。互穿可增加聚合物间相容性。比较系统地总结了合成IPN阻尼材料的分子设计途径。提出了IPN中高分子结构、分子间氢键及其它结构参数对IPN材料阻尼性能产生影响的基本原因。此外,明确了一些IPN研究中的基本概念以及所用名称的意义。     

PEMA/PEA自交联乳胶IPN阻尼材料的研究

利用种子乳液聚合和双丙酮丙烯酰胺与己二酰肼的交联反应合成了PEM A/PEA乳胶IPN。DM S结果表明,组成比对L IPN的相容性和阻尼性能有显著的影响;组成比为35/65的L IPN具有较优异的阻尼性能;界面自交联能改善组分相容性,但使材料的阻尼性能有所下降。拉伸实验结果表明,增加硬组分和交联剂的含量,拉伸强度显著增加。     

PF／PnBA IPN的合成及相容性研究

本文采用乳液和溶液聚合法合成PF/PnBA IPN,并对产物进行了动态力学性能、热重分析及微观形态研究。结果表明,IPN可使组分相容性得到提高热性能得以改善,乳液聚合与溶液聚合法合成IPN产物的微观形态有所不同。     

两类室温固化的蓖麻油聚氨酯互穿网络材料

研究了五种取代乙烯分别与蓖麻油聚氨酯生成的互穿网络聚合物(IPN)的力学性能与其组成的关系,指出聚氨酯含量在65％左右拉伸强度最大,最大强度与取代乙烯均聚物的玻璃化转变温度有关。NCO/OH比愈大,IPN的交联密度愈大,伸长率愈小,拉仲强度愈大。由丙烯酸丁酯生成的IPN具有弹性体性能。还研究了蓖麻油聚氨酯与不饱和聚酯及取代乙烯生成的IPN,指出丙烯腈作为取代乙烯所得的IPN性能最好,不饱和聚酯与丙烯腈的重量比不宜超过1/1。后一IPN的扫描电镜照片表明具有微观相分离的形态结构。     

引入共聚组分改善PMMA/PnBA乳胶IPN的相容性

聚甲基丙烯酸甲酯／聚丙烯酸正丁酯(PMMA／PnBA)乳胶IPN的相容性较差，从溶度参数和结构等方面考虑，有目的地选择单体与nBA共聚，合成了一系列PMMA／P(nBA—co—Y)乳胶IPN，测定了其动态力学性能。结果表明，乳胶体系的相容性有明显改善。研究还表明，共聚单体间的竞聚率影响LIPN的相容性；改变共聚单体的用量可控制LIPN的相容性。还发现，共聚网络具有更好的阻尼特性。     

PU/VER IPN材料阻尼性能的研究

采用DMA法研究了热力学、动力学因素及组成比对聚氨酯/乙烯基酯树脂互穿聚合物网络(PU/VER IPN)材料阻尼性能的影响。研究发现:引入丙烯酸酯类单体为VER共聚单体,改善了常规以苯乙烯(St)为共聚单体的PU/VER(St)IPN材料的阻尼性能,含较长酯基的体系具有更优的阻尼性能;通过调整两网络的相对聚合速率及组成比,可使材料出现宽温域阻尼,合成的组成比为80/20、70/30及60/40的IPN材料,在至少近80℃的温域,阻尼因子(tanδ)>0.3。进一步通过TEM检测分析了IPN材料微观结构与阻尼性能的关系。     

聚环氧氯丙烷聚氨酯/聚甲基丙烯酸甲酯互穿网络的合成与动态力学行为

本文选用聚环氧氯丙烷(PECH)、甲苯二异氰酸酯(TDI)和三甲醇丙烷(TMP)组成网络Ⅰ,甲基丙烯酸甲酯(MMA)和乙二醇二甲基丙烯酸酯(EGDM)组成网络Ⅱ,制成了一组 IPN 材料,研究了它们的动态力学性能。动态力学损耗谱表明:这组 IPN 的阻尼因子 tanδ在很宽的温度范围有较高的值。文中详细讨论了聚合反应条件、网络组成、交联度对阻尼因子以及相容性的影响。     

聚氨酯/环氧树脂互穿聚合物网络半硬泡沫的结构与性能

采用同步法合成了聚醚型聚氨酯/环氧树脂互穿聚合物网络半硬泡沫.通过FTIR,DMA,SEM研究了IPN半硬泡沫的化学结构、动态力学性能以及微观结构形态.FTIR分析表明了聚氨酯和环氧树脂的网络间存在接枝反应.很宽组成比范围内IPN半硬泡沫均显示出单一的宽温域玻璃化转变,而且该转变随着环氧树脂含量的增加向高温方向移动.通过SEM发现IPN半硬泡沫泡孔结构形状都比较均一.循环加载压缩发现所有IPN泡沫不仪压缩性能好而且具有很好的回弹性,大变形压缩后泡沫儿乎不变形,重复使用性能好.     

聚氨酯/聚硅氧烷IPN阻尼弹性体研究

由聚氨酯（聚四氢呋喃醚、液化MDI）、端羟基聚硅所烷齐聚物室温催化合成的一系列的聚氨酯／聚硅氧烷IPN阻尼弹性体。其中拉伸强度最佳值Ts＝46．0MPa，断裂伸长率E＝430％，同时，tanδ＞0．3的温度范围高于30℃。研究认为，由齐聚物在室温交联形成IPN可以较有效地阻止进一步相分离。FTIR发现IPN中聚氨酯和聚硅氧烷网络之间没有化学键形成，聚氨酯的交联反应仍为二级反应，但形成速率降低了两个数量级。SEM、AFM和XPS研究表明，含少量苯基侧基聚二甲基硅氧烷与聚氨酯有良好的相容性，在IPN中形成微米级微结构；聚醚分子量对聚氨酯的软硬链段比例和网络交联密度以及IPN的形态结构和性能都有很大影响；XPS研究发现，主要元素C、N、Si、O在IPN的表面和内部的分布是不均匀的，聚硅氧烷趋向于分面IPN的表面。TG－IR分析聚氨酯／聚硅氧烷IPN的热裂解行为发现，聚硅氧烷的加入提高了IPN的热稳定性，聚氨酯／聚硅氧烷IPN的热裂解机理与纯聚氨酯和聚硅氧烷的热裂解机理一致。聚氨酯／聚硅氧烷IPN由于具有高强度阻尼弹性体的力学特征，同时具备优良的耐热、耐溶剂性，具有潜在的特殊应用前景。     

光固化型聚氨酯/环氧树脂IPN的制备与表征

采用ＩＰＮ技术,制备了一系列光固化型的聚氨酯与环氧树脂的ＩＰＮ树脂,经力学性能测试表明当ＰＵ／ＥＰ＝７０／３０时,ＩＰＮ的断裂伸长率达１６０％。,拉伸强度比纯ＰＵ提高２１０％,显示出良好的正协同效应。利用红外光谱,光谱微镜,应力－应变,硬度等测试手段对ＰＵ／ＥＰ的互穿网络的结构：两组分的相容性,微相分离的形态结构进行了表征。并且探讨了ＩＰＮ的结构与力学性能之间的关系及影响因素,认为：ＰＵ／ＥＰ的Ｉ     

Morphology,mechanical and thermal properties of nano-structured full IPNs based on polyisoprene and PMMA

Morphology, mechanical properties, thermal stability and gas transport behaviour of interpenetrating polymer networks (IPNs) based on PI/PMMA have been investigated using various techniques. Crosslinking level of both phases and concentration of PMMA were found to have noticeable effects on the compatibility of immiscible components during IPN formation. Effect of crosslinking was studied by preparing IPNs with varying amount of crosslinker concentration in each phase. Crosslinking of both phases facilitated deeper interpenetrations between both networks, and certain degree of compatibility is attained during IPN formation. Nanometre-sized domains were observed for highly crosslinked IPN. Lower concentration of PMMA was found to favour phase mixing more effectively than others. DSC curve of 65/35 IPN showed a broad transition arising from the α and β-relaxations of PMMA due to the higher flexibility attained by mixing with the highly mobile PI chains. The mechanical properties of the IPNs were correlated to the morphology of the system and 50/50 composition showed maximum mechanical properties among the studied compositions. Mode of mechanical failure, thermal stability and gas transport behaviour were also analysed. IPNs having nanometre-sized domains showed least gas permeability among the studied samples.     

PU(HTPB)/P(MMA-co-EGDMA)同步互穿网络的合成、形态与力学性能

研究了 PU(HTPB)/P(MMA-co-EGDMA)-IPN 的合成、形态和力学性能。结果表明,两网络的相对形成速率对 IPN 的形态和性能有显著的影响。当两网络形成大致同步时,微区尺寸适中,界面互穿良好,IPN 的综合力学性能最佳。两网络交联密度对 IPN 的力学性能也有显著影响,但只有先形成的网络的交联密度变化才会引起形态的明显改变。     

三元IPN PU/EP/PBA弹性体的研究(Ⅰ)组成与形态的关系

研究了三元ＩＰＮ ＰＵ／ＥＰ／ＰＢＡ的形态结构及其影响因素,研究表明,在一定合成条件下,ＩＰＮ在形态上具有单一均相结构,同时网络关联密度,组分比例,ＰＵ的预聚体结构等因素对其形态有重要影响。在此基础上,分析建立了组成－形态－性能关系,并引入后凝胶时间概念对三元ＩＰＮ中全ＩＰＮ与半ＩＰＮ的形态差异作出解释 。     

聚氨酯/聚硅氧烷IPN阻尼材料研究

以聚四氢呋喃醚MDI聚氨酯和聚二甲基硅氧烷合成PU／PDMS IPN阻尼材料,用SEM和XPS分析了IPN的形态结构和元素分布,用DMA分析了动态力学性能,结果表明,各聚合物组分在IPN表面和内部的分布是不均匀的,这种不均匀性与PU与PDMS的相容性及组成比例有关。     

Hydrogel-elastomer composite biomaterials: 2. Effects of aging methacrylated gelatin solutions on the preparation and physical properties of interpenetrating polymer networks

This study was conducted to understand the effects of aging methacrylated gelatin solutions on the properties of gelatin-HydroThane^TM Interpenetrating Polymer Network (IPN) films. The latter were prepared from methacrylated gelatin solutions that were either freshly made or stored at different concentrations and temperatures for various periods. The morphology, swelling stability and mechanical properties of the IPNs were then accordingly characterized. The IPNs prepared with aged solutions showed a reduced phase separation; changed from a network-like structure to a continuous phase structure; and demonstrated higher swelling stabilities and higher elasticity under optimal aging conditions, compared to the IPN prepared with a fresh methacrylated gelatin solution. An increase in viscosity and a change in phase transition of aged methacrylated gelatin solutions were also observed, presumably due to the physical structuring of methacrylated gelatin chains (e.g., by the formation of a helix structure), thus altering the resulting IPN characteristics. A better understanding of the effects of aging methacrylated gelatin solution on the formation and properties of gelatin-HydroThane^TM IPNs should enable us to further develop our composite biomaterials for different dressing applications.     

3D Printing of Dual-Cure Networks Based on (Meth)acrylate/Bispropargyl Ether Building Blocks

In recent years, dual-cure chemistry has been exploited to realize interpenetrating networks (IPNs) that provide enhanced thermo-mechanical properties. In this contribution, photoinduced curing of (meth)acrylates is used to build the desired 3D structure, whereas the thermally triggered polymerization reaction of 2H-chromene functionalized building blocks is utilized to create the IPN. This strategy combines the advantages of traditional UV-curable monomers with high-performance thermosets. After the successful synthesis of the bispropargyl ether derivative, i.e., 4,4′-(propane-2,2-diyl)bis((ethynyloxy)benzene), its thermally induced conversion to the corresponding 2H chromene functionalized prepolymer is studied by Fourier-transform infrared spectroscopy and gel permeation chromatography. The network formation as well as the printability of various formulations containing different amounts of the thermo-curable building block is investigated. The obtained IPNs provide enhanced thermo-mechanical properties making these resins suitable for the additive manufacturing of functional 3D parts for high-performance applications.     

环氧树脂/聚氨酯半互穿网络聚合物的研究Ⅰ.玻璃化转变行为及其形态结构

用分步法制备了环氧树脂／聚氨酯（ＥＰ／ＰＵ）半ＩＰＮ，通过差示扫描量热法（ＤＳＣ）与动态力学分析法（ＤＭＡ）研究了该半ＩＰＮ的玻璃化转变行为，用扫描电镜（ＳＥＭ）表征了其形态结构。结果表明，在此半ＩＰＮ中，两组分聚合物的玻璃化转变温度（Ｔｇ）靠近，并伴随有第三个Ｔｇ的出现。该半ＩＰＮ具有两相结构，两相连续程度随组分量的变化而变化。     

Gradient interpenetrating polymer networks

The methods of synthesis and properties of gradient interpenetrating polymer networks (IPN) are discussed based on literature and authors' own experimental data. Gradient IPN can be treated as a sequence of an infinite number of layers of IPNs, whose composition and properties vary gradually from the surface to the core of specimens. These are analysed the most important properties of gradient IPNs: temperature transitions, thermodynamic and physico-mechanical characteristics and the main direction of practical application of gradient IPN-based materials.