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松香季戊四醇酯(RPE)环上的共轭双键可以与甲基丙烯酸-2-羟乙酯(HEMA)发生Diels-Alder加成发应,同时松香季戊四醇酯仍有一定酸值,其中未反应的羧基可与HEMA进行酯化反应。研究了反应温度和物料配比对RPE与HEMA反应的影响,对产物进行了红外和热重分析。结果表明:在一定的物料比下,反应温度升高,加成反应和酯化反应速度加快,反应温度提高更有利于酯化反应的进行;在一定的反应温度下,HEMA的物质的量增加,产物的酸值到一定程度不再下降,而溴值持续下降,表明有利于HEMA与RPE的加成反应。红外光谱表明将HEMA接到了RPE的分子结构上,热重分析表明产物的初始分解温度和最终分解温度有所下降。 相似文献
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Superporous poly(2-hydroxyethyl methacrylate) based scaffolds: Preparation and characterization 总被引:1,自引:0,他引:1
Superporous poly(2-hydroxyethyl methacrylate) (PHEMA) scaffolds with pore size from 101 to 102 μm range were prepared by radical polymerization of 2-hydroxyethyl methacrylate (HEMA) with 2 wt.% ethylene dimethacrylate (EDMA) with the aim to obtain a support for cell cultivation. Superpores were formed by salt-leaching technique using NaCl or (NH4)2SO4 as a porogen. Addition of liquid porogen (cyclohexanol/dodecan-1-ol (CyOH/DOH) = 9/1 w/w) to the polymerization mixture did not substantially affect the formation of meso- and macropores. The prepared slabs were characterized by several methods including water and cyclohexane regain by centrifugation, water regain by suction, scanning electron microscopy (SEM), mercury porosimetry and dynamic desorption of nitrogen. High-vacuum scanning electron microscopy (HVSEM) confirmed permeability of hydrogel slabs to 8-μm microspheres, whereas low-vacuum scanning electron microscopy (LVSEM) at cryo-conditions showed the undeformed structure of the frozen slabs. Interconnection of pores in the PHEMA slabs was proved. Water regain estimated by centrifugation method did not include volume of large superpores (imprints of porogen crystals), in contrast to water regain by suction method. The porosities of the slabs ranging from 81 to 91% were proportional to the volume of porogen in the feed. 相似文献
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甲基丙烯酸树脂光刻胶是传统的光刻胶之一,具有高度的透明性及分辨率。以二氧六环为溶剂,偶氮二异丁腈为引发剂,采用了自由基溶液聚合合成了甲基丙烯酸甲酯/甲基丙烯酸/甲基丙烯酸酰氯三元共聚物,并利用烯丙醇制备了侧链上带有烯丙基的甲基丙烯酸酯感光高分子。用FT-IR和1HNMR图谱确认了结构,用凝胶色谱测定其相对分子质量,并从引发剂浓度、聚合温度、单体配比等方面进行讨论,同时对其光刻性能进行了研究。 相似文献
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Transparent PMMA/ZrO2 nanocomposites were prepared by in-situ bulk polymerization of methyl methacrylate (MMA)/ZrO2 dispersions that were firstly synthesized using nonaqueous synthesized ZrO2 nanocrystals and the function monomer, 2-hydroxyethyl methacrylate (HEMA), as the ligand. The dispersion behavior of ZrO2 nanoparticles in MMA, structure, mechanical and thermal properties of the PMMA/ZrO2 nanocomposites were investigated comprehensively. It was found that ZrO2 nanoparticles were well dispersed in MMA with HEMA ligand, but the MMA/ZrO2 dispersions easily destabilized in air as well as at elevated temperatures. The destabilization temperature of the dispersion is raised by increasing the molar ratio of HEMA/ZrO2 to match the bulk polymerization temperature. The PMMA/ZrO2 nanocomposites showed an interesting chemical structure (namely, highly cross-linked structure even at ZrO2 content as low as 0.8 wt% and hydrogen bonding interaction between polymer matrix and ZrO2 nanoparticles), with enhanced rigidity without loss of the toughness and improved thermal stability. The relationship between the structure and the properties of the PMMA/ZrO2 nanocomposites based on the HEMA coupling agent was discussed. 相似文献
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K. Sreenivasan 《Polymer International》1997,42(1):22-24
2-Hydroxyethyl methacrylate (0·01mol) was allowed to react with 0·01mol of hexamethylene di-isocyanate and the product was coupled to 0·01mol of β-cyclodextrin to form a new cyclodextrin-based copolymer. The interaction of the polymer with different steroids was investigated and the extent of adsorption was in the order cholesterol>progesterone>testosterone. The results indicate that the new polymer matrix could be used for the removal of steroids, particularly cholesterol, from a given medium. The polymer could also be used for sample purification, such as the removal of progesterone from a mixture prior to its analysis by other analytical techniques. The preliminary results show that the polymer may have interesting clinical and analytical applications. © of SCI. 相似文献
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Paveena Tangudom Ekachai Wimolmala Benjaphorn Prapagdee 《Polymer-Plastics Technology and Engineering》2018,57(18):1963-1976
Polymer blends of poly(methyl methacrylate)(PMMA) and acrylic rubber(AR) were manufactured with the addition of titanium dioxide (TiO2). TiO2 was initially added to the AR phase in AR/PMMA blends. The impact strength of PMMA improved with AR loading. The addition of TiO2 appeared to decrease the tensile properties of the blends with AR of 10-30?wt% of AR, but increased with AR of 40-50?wt%, this being related to distribution level of TiO2. UV radiation deteriorated the overall mechanical properties, where TiO2 could retain the properties. To achieve acceptable antibacterial performance, AR loadings of 40 and 50?wt% in AR-TiO2/PMMA blends are recommended, together with TiO2 loadings of 1.5?pph and 0.5?pph, respectively. 相似文献
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Mubarak A. Khan M. Arifur Rahman Ruhul A. Khan Nazia Rahman Jahid M. M. Islam Rashidul Alam 《Polymer-Plastics Technology and Engineering》2013,52(7):748-756
The chitosan/starch blend films of 2:1 ratio were prepared by solution casting. Tensile strength (TS) and elongation at break (%Eb) of chitosan/starch blend film were found to be 9.33 MPa and 3.6%, respectively. The blend films (2% Chitosan) were soaked in six different formulations of methylmethacrylate (MMA) monomer and aliphatic urethane diacrylate oligomer (M-1200) at different time intervals (1–5 min) and irradiated under UV radiation at different intensities (5–35 pass). Formulations containing 43% MMA and 15% oligomer in methanol solution showed 209% increase in TS at 25th UV pass for 4 min soaking time. SEM and FTIR were used to investigate the molecular interaction and morphology of the blend film, respectively. 相似文献
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该文对以金刚砂为磨料、SiO2为填充物、光固化树脂为结合剂的超薄砂轮光固化材料进行了DSC、TG分析。结果表明,SiO2的使用会影响固化材料的玻璃化温度,当SiO2质量分数由0增加到10%时,材料的玻璃化温度由43 86℃增加到45 92℃,热失重率由93%增加到98%;金刚砂的加入使材料的耐热性能有所下降,与纯树脂的固化材料相比,在同一温度下,热失重率都将增加1%~2%;金刚砂及SiO2的加入使得光固化树脂对紫外光的透过率下降,为了使材料固化完全,减少热失重率,固化时可采用光固化与热固化相结合的方法。 相似文献
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采用紫外光谱分析法在体外研究了纳米TiO2对胶原的紫外屏蔽作用。结果表明纳米TiO2对胶原具有显著的紫外屏蔽作用。并且2.5%TiO2比0.5%TiO2的添加量对胶原的紫外屏蔽作用更强。 相似文献
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以环氧氯丙烷(ECH)作为羟丙基纤维素(HPC)和明胶(GEL)的交联剂,通过均相混合、交联、溶液浇铸、蒸发等工艺制备了一系列ECH交联的HPC/GEL复合膜(EHGF)。利用傅里叶红外光谱(FTIR)、X射线衍射仪(XRD)、紫外-可见分光光度计(UV-Vis)、扫描电子显微镜(SEM)、热重分析仪(TG)、接触角、力学性能等测试手段对EHGF复合膜的结构、微观形貌、热稳定性、耐水性及拉伸断裂强度进行表征和分析。结果表明:交联作用存在于HPC和GEL组分之间,各组分间具有好的相容性;与HPC/GEL共混膜相比,EHGF复合膜显示了更均匀致密的断面形貌和更高的热稳定性,且ECH的交联作用显著提高了HPC/GEL复合膜的水接触角和断裂强度。 相似文献
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Chiral (+)-bornyl methacrylate and achiral (±)-bornyl methacrylate were synthesized from (+)-camphor and (±)-camphor, respectively. To investigate the influence of the steric environment of the chiral polymers on the electro-optical characteristics of polymer-dispersed liquid crystal (PDLC) films, a commercially available positive nematic liquid crystal E7 was dispersed in the chiral and achiral polymer matrices. The electro-optical characteristics and the microstructures of the PDLC films with chiral and achiral racemized polymers were investigated. It was found that PDLC films with chiral polymers have relatively high contrast ratio and fast falling speed, but there exists a transient damping response when a square pulse of 20ms and 60V is applied. Two distinct morphologies were observed: (1) a ‘continual channel’ with the chiral polymer matrix, and (2) an ‘isolated ball’ with the achiral racemized polymer matrix. The reversible turbid and transparent changes with an applied a.c. electric field were also investigated. © of SCI. 相似文献
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2-乙烯基吡啶-甲基丙烯酸甲酯两嵌段共聚物的合成与表征 总被引:2,自引:2,他引:0
采用阴离子活性聚合方法合成了聚2-乙烯基吡啶(P2VP)-聚甲基丙烯酸甲酯(PMMA)两嵌段共聚物(P2VP-b-PMMA),并采用GPC、FT-IR、NMR等手段进行了结构表征.结果表明,聚合产物为数均分子量103166、多分散指数1.08的单分散P2VP-b-PMMA. 相似文献
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以SiO2纳米粒子为种子的甲基丙烯酸甲酯乳液聚合 总被引:8,自引:0,他引:8
本文采用SiO2纳米粒子作为种子进行了甲基丙烯酸甲酯的乳液聚合。初步探讨了此类种子乳液聚合的过程;也分析了SiO2的用量对所生成的残渣率的影响,SiO2在残渣中的实际含量均比在乳液聚合物中略高,这是由于总有一些单体转移到不含SiO2的自由胶束中进行聚合而造成的。所得的复合乳液聚合物的力学和热学性能测试结果表明材料的这两种性能均随SiO2含量的增加而降低。 相似文献