天然橡胶接枝甲基丙烯酸羟乙酯的合成与表征

以甲基丙烯酸羟乙酯(HEMA)为接枝单体,过氧化二苯甲酰(BPO)为引发剂,合成了天然橡胶(NR)接枝聚甲基丙烯酸羟乙酯(NR-g-HEMA)。研究了BPO和HEMA用量、反应温度、反应时间以及NR塑炼时间对单体转化率、接枝率和接枝效率的影响,并采用红外光谱对接枝产物进行了表征。结果表明:当BPO用量为3%,HEMA用量为30%,反应温度为80℃,反应时间和NR塑炼时间分别为4h和30min时,NR-g-HEMA的接枝率达16%。     

松香季戊四醇酯与甲基丙烯酸-2-羟乙酯反应研究

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。     

Superporous poly(2-hydroxyethyl methacrylate) based scaffolds: Preparation and characterization

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.     

甲基丙烯酸酯光刻胶的制备与表征

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。     

Preparation and properties of transparent PMMA/ZrO2 nanocomposites using 2-hydroxyethyl methacrylate as a coupling agent

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.     

UV混杂固化树脂的合成及应用研究

对光敏环氧树脂单丙烯酸酯的合成方法进行了研究,讨论了催化剂、反应温度等因素对反应及产物性能的影响。同时将产物用于UV固化油墨配方,性能理想。     

甲基丙烯酸2，2，2-三氟乙酯的制备及聚合

甲基丙烯酸2，2，2-三氟乙酯是一种重要的有机含氟聚合物单体，具有独特的物化性质，被广泛应用于涂料、光学纤维和接触镜片等领域。     

Synthesis and Evaluation of β-Cyclodextrin–2-Hydroxyethyl Methacrylate Copolymer as a Novel Adsorbent

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.     

甲基丙烯酸二乙氨基乙酯的合成

以甲基丙烯酸和草酰氯为原料,配比为n（甲基丙烯酸）：n（草酰氯）=1：1．08,草酰氯法合成了甲基丙烯酰氯：以二乙氨基乙醇与甲基丙烯酰氯为原料,乙醚为溶剂进行酰基化反应,配比为n（甲基丙烯酰氯）：n（二乙氨基乙醇）=1：1．6,冰浴下反应4h,合成了一种用途广泛的多功能单体甲基丙烯酸二乙氨基乙酯（DEAM）,相对于甲基丙烯酰氯的收率为94．4％。     

Material Formulations for AR/PMMA and AR-TiO2/PMMA Blends and Effects of UV Radiation and Tio2 Loading on Mechanical and Antibacterial Performances

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.     

聚甲基丙烯酸甲酯大分子单体的合成及表征

甲基丙烯酸甲酯进行自由基溶液聚合 ,巯基乙醇为链转移剂 ,然后用丙烯酰氯封端制备了聚甲基丙烯酸甲酯大分子单体。研究了引发剂、反应时间、溶剂、反应温度对预聚体的产率的影响。对所合成的大分子单体进行了 IR、1H-NMR表征。适宜的反应条件为用 THF作溶剂 ,60℃反应 7～ 8h,预聚体可以达到80 %的产率。     

Preparation and Characterization of the Mechanical Properties of the Photocured Chitosan/Starch Blend Film

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.     

热分析法研究含SiO2、金刚砂填充物的光固化材料

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。     

PbSe/聚甲基丙烯酸甲酯纳米复合材料的制备及表征

采用超声电化学法制备出水相硒化铅(PbSe)纳米晶体,并将其掺杂到聚甲基丙烯酸甲酯(polymethyl methacrylate,PMMA)材料中,通过本体聚合法制备出PbSe/PMMA纳米复合材科.用X射线衍射、透射电镜、扫描电镜对PbSe纳米晶体和PbSe/PMMA纳米复合材料的形貌进行了表征.结果表明:超声电化...     

纳米TiO2对胶原的紫外屏蔽作用

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。     

羟丙基纤维素/明胶复合膜的制备及性能表征

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。     

Preparation and Characterization of Polymer-dispersed Liquid Crystal Films Using Poly(bornyl methacrylate)

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.     

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

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.     

紫外辐射法低温制备柔性TiO_2薄膜电极及其性能研究

采用先研磨后超声波分散的方法制备了TiO2涂膜胶体,由其涂敷的TiO2薄膜经过紫外辐射处理后,获得了组装染料敏化太阳能电池的柔性TiO2薄膜电极。用扫描电子显微镜、红外吸收光谱仪和紫外可见光谱仪对TiO2薄膜电极进行了表征,同时,用数字源表测试了电池的光电性能。结果表明:TiO2薄膜电极具有多孔结构,其经过紫外辐射处理后,有机物完全去除;N3染料敏化后,使其吸光度增大,组装成的电池,其光电转换效率达到0.93%。     

以SiO2纳米粒子为种子的甲基丙烯酸甲酯乳液聚合

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。