HEMA/NVP共聚水凝胶的合成与性能

以甲基丙烯酸2-羟乙酯(HEMA)和N-乙烯基吡咯烷酮(NVP)为原料,偶氮二异丁腈为引发剂,二甲基丙烯酸乙二醇酯(EGDMA)为交联剂,采用溶液聚合法合成HEMA／NVP共聚水凝胶。对其进行了红外光谱分析,考察了交联剂用量(EGDMA)和NVP用量等对该水凝胶材料性能的影响,研究表明该水凝胶具有良好的力学性能与合适的含水量,是一种性能良好的人工角膜材料。     

高性能乳胶手套润滑涂层——高分子水凝胶

用甲基丙烯酸羟乙酯作为主功能单体合成的高分子水凝胶对乳胶手套内表面进行处理。既保持了乳胶手套良好的弹性、滑爽性与光泽,又使乳胶手套具有一定的吸水性,穿戴舒适。北京化工大学精细化工厂正生产高分子水凝胶.并与有关生产厂家合作开发这种新型的乳股手套。生产高分子水凝胶树脂具有良好的经济与社会效益。     

Cs-AA-HEMA复合水凝胶的合成及溶胀性能

以壳聚糖、丙烯酸、甲基丙烯酸羟乙酯为原料,硝酸铈铵、过氧化二苯甲酰为引发剂,戊二醛为交联剂,制备了壳聚糖-丙烯酸-甲基丙烯酸羟乙酯复合水凝胶,探讨了凝胶溶胀过程和理论,研究了凝胶合成条件及溶剂性质对凝胶平衡溶胀度的影响.结果表明：随着丙烯酸浓度、甲基丙烯酸羟乙酯添加量的增加,凝胶平衡溶胀度先增大再减小,凝胶溶胀度随着戊二醛浓度增加而减小.壳聚糖-丙烯酸-甲基丙烯酸羟乙酯复合水凝胶是pH/离子/温度敏感型凝胶.     

四元共聚水凝胶的合成、表征及吸水性研究

以水为分散介质,以丙烯酰胺(AM)、丙烯酸(NaAA)、丙烯酸羟丙酯(HPA)为共聚单体,甲基丙烯酸缩水甘油酯(GMA)为交联单体,通过自由基聚合制得新型水凝胶。考察了各单体用量对水凝胶吸水性能的影响,发现AM∶NaAA∶HPA摩尔比为0.5∶2∶1,GMA用量为1 wt%,水凝胶吸水倍率达到410 g/g。用红外光谱对水凝胶的结构进行了表征。     

水凝胶接触镜材料进展

采用水凝胶材料制造的角膜接触镜具有含水量高、配载舒适，透氧率高等特点，本文综述了各种水凝胶角膜接触镜材料的特点，并综述了水凝胶角膜接触镜材料的透氧机理、制备方法以及成型技术。     

水凝胶角膜接触镜材料及其应用

简要叙述了制造角膜接触镜的水凝胶类材料，并综述了水凝胶角膜接触镜成型技术以及水凝胶材料角膜接触镜的应用。     

聚乙烯吡咯烷酮/壳聚糖共混水凝胶的制备与水的状态

以戊二醛作为交联剂,制备了聚乙烯吡咯烷酮（PVP）/壳聚糖（CHI）共混水凝胶,共混物的玻璃化转变温度T_g随CHI含量的升高而升高,SEM图谱观察到PVP/CHI凝胶表面呈现随CHI∶PVP比而变化的微相分离.凝胶溶胀率随着PVP含量升高、PVP分子量降低、CHI脱乙酰度增大而升高.DSC分析表明,非冷冻状态下,CHI∶PVP为1∶2时,游离水、可冻结结合水、非冻结结合水含量分别为42.7%、43.3 %、14.0 %;CHI∶PVP为1∶8时,凝胶中含非冻结结合水少,DSC曲线上只有一个明显的失水吸热峰,由游离水与可冻结结合水叠加而成.-123℃冷冻条件下凝胶的DSC升温曲线在0、38、53℃观察到一组明显的焓化峰,这是由于低温时冻结为结晶相的游离水、可冻结结合水,随温度升高吸热又转化为游离水、可冻结结合水所致.     

丙烯酰胺类共聚物水凝胶的合成及性能研究

用自由基聚合法合成了不同摩尔配比的HEMA／AM共聚物水凝胶材料。研究了单体组成、温度、pH值、离子强度等因素对凝胶溶胀性能的影响。结果表明：水凝胶的溶胀速度较快;水凝胶在pH值小于4及pH值大于9的酸、碱溶液中发生水解,导致水凝胶的饱和含水量大幅增加,而在弱酸性溶液中几乎没有变化;水凝胶的饱和含水量对离子强度的变化不够敏感;随着温度的升高水凝胶的饱和含水量略有减少,说明此类水凝胶对温度的敏感性也较弱。     

硅水凝胶隐形眼镜材料的合成与性能研究

以甲基丙烯酸羟乙酯（HEMA）、N-乙烯基毗咯烷酮（NVP）和γ-（甲基丙烯酰氧）丙基三甲氧基硅烷（KH-570）为单体,以偶氮二异丁腈（AIBN）为引发剂,通过本体聚合反应合成新型硅水凝胶角膜接触镜.考察了各单体配比、反应温度等对聚合的影响.结果表明,当反应温度为90℃,反应时间为2h,V（HEMA）：V（NVP）：V（KH-570） =8∶ 1∶1时,合成的隐形眼镜透氧量（DK/t）达到64.0×10-9（cm3O2·cm）/（cm2·s·mmHg）,含水量38％,透光率95.5％以上.     

丙烯酰胺在水凝胶角膜接触镜材料制备中的应用研究

对丙烯酰胺(AM)在水凝胶角膜接触镜材料制备中的应用进行了探讨,确定了AM/甲基丙烯酸β-羟乙酯(HEMA)交联共聚水凝胶角膜接触镜材料适宜的制备工艺,即:采用本体聚合法,以过氧化苯甲酰(BPO)作引发剂,其质量分数为0.2%(基于单体混合物质量),反应温度为70℃左右,反应时间为24 h。在饱和溶解度以下,AM可与HEMA以任意摩尔比共聚,所得聚合物的透光率、饱和含水率和机械强度均能满足水凝胶角膜接触镜材料相关要求。     

水在凝胶中的存在状态及其对凝胶力学性能的影响

以偶氮二异丁腈为引发剂,通过化学引发聚合合成甲基丙烯酸β-羟乙酯（HEMA）/N-乙烯基吡咯烷酮（NVP）二元共聚物和HEMA /NVP /甲基丙烯酸甲酯（或甲基丙烯酸丁酯）三元共聚物水凝胶,通过示差扫描量热法（DSC）结合热重法（TG）研究了不同单体配比的共聚物水凝胶中水的状态,证明了凝胶中存在3种不同状态的水：非冻结结合水、可冻结结合水和可冻结自由水.结果发现可冻结水的含量主要由NVP含量所决定,NVP单元基本不能键合水,而非冻结水的含量主要受HEMA含量和疏水性单体甲基丙烯酸酯含量影响.疏水性单体的引入使材料的力学强度提高,对凝胶体系具有增塑作用的是非冻结水而不是可冻结的结合水和自由水.     

三元丙烯酸酯共聚物乳液研究

合成了无规共聚物———聚(甲基丙烯酸甲酯/丙烯酸乙酯/甲基丙烯酸)[P(MMA/EA/MAA)],并对其结构和性能进行了研究。考察了单体用量、引发剂用量和温度对乳液粒径的影响,结果表明,随着单体和引发剂用量的增加,乳液粒径也随之增加。     

Sorption of lysozyme by HEMA copolymer hydrogels

Sorption of lysozyme by 2-hydroxyethyl methacrylate (HEMA) copolymer hydrogels was studied as a function of pH and gel composition. Three types of HEMA gels were synthesized: neutral (HEMA), acidic (HEMA + acrylic acid), and basic (HEMA + dimethylaminoethyl methacrylate). Each gel was synthesized at four initial volume fractions to obtain different equilibrium swelling ratios and microstructures. Sorption as a function of time was measured for each gel at pH 7, 7.5, and 8. The rate of uptake by the acidic gels was more rapid than that by the neutral gels: To sorb 90% of the protein required only 1 h for the acidic gels but 15 days for neutral gels. Lysozyme did not adsorb or partition into the basic gels. The fractional approach to equilibrium was most rapid for the more swollen gels, and the effect of pH was small. The results reported here may be useful for rational design of new biomaterials where it is desirable to know the relative magnitude of the effects of composition, synthesis, and pH on protein sorption. © 1996 John Wiley & Sons, Inc.     

MPEGMA-SMAS-IA三元共聚减水剂的合成及性能

以MPEGMA(马来酸单聚乙二醇单甲醚酯)、SMAS(甲基丙烯磺酸钠)和IA(衣康酸)等为主要原料,通过分子结构设计合成了MPEGMA-SMAS-IA三元共聚的聚羧酸系减水剂,并考察了单体配比、引发剂含量和聚合时间等对其性能的影响。研究结果表明:当n(MPEGMA):n(SMAS):n(IA)=1:0.9:0.2、聚合温度为80℃、聚合时间为5 h和w(引发剂)=10%(相对于单体总质量而言)时,聚羧酸系减水剂的综合性能相对较好;以此作为改性剂,当w(减水剂)=0.33%(相对于水泥质量而言)、水灰比为0.29时,改性水泥净浆的流动度(272 mm)相对最大。     

Mechanical response and equilibrium swelling of thermoresponsive copolymer hydrogels

Covalently crosslinked thermoresponsive (TR) gels form a special class of hydrogels that swell noticeably below their volume phase transition temperature T_c and shrink above T_c. As the critical temperature is weakly affected by the preparation conditions and molar fractions of monomers and crosslinkers in the pre‐gel solution, a facile method to modulate T_c (which is required for biomedical applications of TR gels and their use as temperature‐triggered actuators) is to incorporate relatively small amounts of neutral monomers whose hydrophilicity differs from that of the basic monomers. Although observations on copolymer gels confirm the effectiveness of this method, the molar fractions of comonomers necessary for the tuning of T_c remain unknown. A model was developed for the mechanical response and equilibrium swelling of TR gels. Adjustable parameters in the governing relations were found by fitting equilibrium swelling diagrams for poly(N‐isopropylacrylamide) homopolymer and copolymer gels. Good agreement is demonstrated between the experimental data and the results of simulation. Based on the model, an analytical formula is derived that expresses the volume phase transition temperature in terms of the molar fraction of comonomers. Its ability to predict the critical temperature is confirmed by comparison with observations on several copolymer gels. © 2020 Society of Chemical Industry     

三元共聚氨基苯乙烯微球的制备

用无乳聚合法制备了苯乙烯－甲基丙烯酸－β－羟丙酯－丙烯酸（Ｓｔ－ＨＰＭＡ－ＡＡ０三元共聚高分子微球,再进行硝化及还原反应制成了凿径均匀,稳定性好的三元共聚氨基苯乙烯微球。测定了其粒径分布和ζ－电位,讨论了高分子反应的的条件与粒径分布等因素对微球性质的影响。     

丙烯腈-丁二烯-异戊二烯三元无规共聚物的催化加氢及表征

以三(三苯基膦)氯化铑[RhCl(PPh3)3]为催化剂,甲苯为溶剂,对自制的丙烯腈-丁二烯-异戊二烯三元无规共聚物(NBIR)进行催化加氢,考察了反应温度、催化剂用量对加氢反应的影响,采用核磁共振氢谱、傅里叶变换红外光谱、差示扫描量热分析和热重分析等方法对氢化物进行了分析表征。结果表明,在反应温度为145℃、反应压力为3 MPa、催化剂质量分数占原胶的0.46%、反应时间为3 h的条件下,该催化剂对NBIR有最高加氢反应活性,氢化度可达到76.1%,氢化物只有1个玻璃化转变温度(-15.9℃),耐热分解性明显改善。     

Hardness of irradiated hydroxyethyl methacrylate copolymer at elevated temperatures

The hardness of irradiated hydroxyethyl methacrylate (HEMA) copolymer at elevated temperatures was measured using a microhardness tester. The hardness increases with annealing time, and is attributed to the defects present in the molecular chains. The defects that control the hardness are related to the entanglement of polymer chain and follow a first order kinetics process. The relaxation time satisfies the Arrhenius equation, with constant activation energy of 25 kJ/mol independent of the irradiation dose. The results were compared with those of PMMA and LiF single crystals reported in the literature. The present findings are useful in the study of soft contact lens, kidney dialysis system, drug delivery system, and artificial liver support system. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Kinetics and thermodynamics of the water sorption of 2‐hydroxyethyl methacrylate/styrene copolymer hydrogels

A series of polymer hydrogels based on 2‐hydroxylethyl methacrylate and styrene were synthesized by bulk polymerization. The kinetic and thermodynamic swelling properties of these hydrogels were studied. The swelling mechanism of the hydrogels followed Fickian behavior. The diffusion coefficients, initial swelling rate, and maximum water uptake all decreased with the styrene content increasing because of the hydrophobicity of styrene. The swelling process was exothermic from 278 to 315 K, and the greater the styrene content was, the lower the enthalpy of mixing was in magnitude. The polymer–water interaction parameter, reflecting thermodynamic interactions, increased with increasing styrene content in the polymers. The negative values and trend of the actual partial molar enthalpy and entropy of dilution could be explained by the structuring of water through enhanced hydrogen bonding and hydrophobic interactions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008