超声波场下辅助引发苯乙烯分散聚合反应的研究

通过实验设计,对超声波场下辅助引发苯乙烯(St)分散聚合反应的可行性进行了研究。结果表明:利用超声波空化作用产生的热点效应,油溶性引发剂偶氮二异丁腈(AIBN)裂解生成自由基可引发St的分散聚合反应。超声波场的工作参数(超声波输出功率、作用时间)对聚苯乙烯(PS)粒子的性能影响很大,适宜的超声波场聚合反应条件为400W×3.0h。     

丙烯酸酯共聚乳液用于增韧改性水性PU的研究

介绍了一种用手改性水性PU皮革涂饰液的丙烯酸酯共聚乳液,对水性PU的硬度和韧性进行调节改性,增加其柔韧和饱满度。讨论了该乳液对水性PU乳液性能的影响。采用了常规的丙烯酸酯乳液共聚工艺,得到一种外观半透明的阴离子型丙烯酸酯乳液,能够与该水性PU产品稳定混合。自然干燥和95℃加热干燥成膜均为透明,柔韧而丰满,与皮革的附着力良好,综合改性效果较好。     

高黏度苯丙乳液的制备

为了制备高性能的苯丙乳液,研究了乳化剂、助剂DZ-1及丙烯酸对苯丙乳液黏度及触变指数等性能的影响。研究结果表明：乳化剂用量低反应生成的凝聚物较多,用量大乳液的气泡较多。乳液的黏度和触变指数随DZ—1用置增大而大幅度提高。乳液黏度随丙烯酸用量的增加而提高,但用量超过3％后,耐水性能变差。乳化剂用量为1．0％,DZ-1用量为4．5％,酸用量为3．0％时合成的苯丙乳液黏度和触变指数较高。用该苯丙乳液配制的涂料黏度高、触变性好,耐擦洗及耐水性好,综合性能优良。     

乳聚丁苯橡胶国内外生产技术及进展

论述了乳聚丁苯橡胶国内和国外生产技术及进展,分析了国内和国外ESBR生产工艺技术特点,技术进步主要围绕优化工艺控制,提高聚合转化率,完善凝聚技术,研制高效引发剂和新型乳化剂,开发不含有亚硝酸胺的环保型ESBR。     

阳离子型含氟聚丙烯酸酯乳液的合成与应用

本文报道了阳离子型含氟聚丙烯酸酯乳液的合成方法,该乳液可用作织物整理。通过对聚合过程中影响因素实验研究,测定了乳液在各种应用条件下的稳定性,并确定织物处理后的拒水、拒油性能、透气性能、撕裂性能。     

Amphiphilic Pentablock Copolymers Prepared from Pluronic and ε-Caprolactone by Enzymatic Ring Opening Polymerization

Amphiphilic copolymers are appealing materials because of their interesting architecture and tunable properties. In view of their application in the biomedical field, the preparation of these materials should avoid the use of toxic compounds as catalysts. Therefore, enzymatic catalysis is a suitable alternative to common synthetic routes. Pentablock copolymers (CUC) were synthesized with high yields by ring-opening polymerization of ε-caprolactone (ε-CL) initiated by Pluronic (EPE) and catalyzed by Candida antarctica lipase B enzyme. The variables to study the structure–property relationship were EPEs’ molecular weight and molar ratios between ε-CL monomer and EPE macro-initiator (M/In). The obtained copolymers were chemically characterized, the molecular weight determined, and morphologies evaluated. The results suggest an interaction between the reaction time and M/In variables. There was a correlation between the differential scanning calorimetry data with those of X-ray diffraction (WAXD). The length of the central block of CUC copolymers may have an important role in the crystal formation. WAXD analyses indicated that a micro-phase separation takes place in all the prepared copolymers. Preliminary cytotoxicity experiments on the extracts of the polymer confirmed that these materials are nontoxic.     

明胶和海藻酸钠的协同作用对乳液稳定性的影响

为了改善目前单一蛋白质明胶(GE)作为乳化剂所制备乳液的不稳定性,研究了明胶和海藻酸钠(AL)复合凝聚物对水包油乳液配方的影响.(电位法和比浊法的分析表明,在总浓度为0.05％和GE与AL的质量浓度之比R为8:1-1:1的比例下,明胶和海藻酸钠由于静电相互作用形成了复合凝聚物.在pH值低于5.1时,2种生物大分子的静电...     

Use of photodegradable inhibitors in UV-curable compositions to form polymeric 2D-structures by visible light

The process of two-wave photopolymerization of a UV-curable composition with an optically degrading inhibitor is considered. By numerical simulation, it is shown that in the composition layer uniformly exposed to UV-radiation, such systems allow getting segments with different conversion under the action of inhomogeneous visible light. Based on the data on the photopolymerization kinetics of the compositions from triethylene glycol dimethacrylate (TEGDMA) and bisphenol-A glycidyl dimethacrylate (bis-GMA) with the UV-initiator 2,2-dimethoxy-2-phenylacetophenone (DMPA), it was shown that 3,5-di-tert-butyl-o-benzoquinone (35Q) with N,N-dimethylaniline (DMA, “Aldrich”, 99%) can serve as an inhibitor that degrades under action of visible radiation. Combining inhomogeneous visible light generated with a conventional DLP-projector and uniform UV-radiation of LED (365 nm) the two-wave lithographic process was implemented to create polymeric 2D-structures in 20 μm layer of the compositions from TEGDMA (70)/bis-GMA (30)/DMPA (0.05 wt%)/35Q (0.5 wt%)/DMA (1 wt%).     

基于聚集诱导发光效应的高固低黏丙烯酸荧光树脂的制备及其性能研究

为了研制一种具有荧光功能特性的高固低黏羟基丙烯酸树脂。从聚集诱导发光效应（AIE）出发,将具有 AIE性质的二对丙烯酸四苯乙烯酯荧光分子通过自由基共聚连接于聚合物链段。由于聚合物链段对荧光分子化学键固定以及聚合物链的包裹束缚作用,导致荧光分子运动受限,从而实现涂层在紫外灯下荧光发光。通过荧光光谱的实时跟踪,探索高固低黏羟基丙烯酸树脂的合成以及固化规律。此外,由于聚合物链段对外界刺激具有实时响应性,从而间接影响了所连接的荧光分子的荧光发光行为。因此,文中也探索了涂层在外界温度与化学气体的影响下所发生的荧光变化的规律,以探索其在功能涂层中应用的可行性。     

Surface modification of multiwalled carbon nanotubes via surface RAFT copolymerization method and capecitabine-loaded anticancer hydrogel for controlled drug delivery in stomach

ABSTRACT

In our work, reversible addition-fragmentation chain transfer (RAFT)/carbon nanotube (CNT)/acrylic acid (AA)/acrylamide (AAm) nanocomposite was synthesized by living radical polymerization. The structure and surface morphology of the synthesized RAFT-CNT-Hydrogel nanocomposites were analyzed by FTIR, ¹HNMR, SEM, TEM, XRD, and TGA/DTG techniques. The results indicated that PAA/AAm chains grafted with CNT by RAFT polymerization. RAFT-CNT-Hydrogel nanocomposites for drug release investigated in different buffers resulted in a strong pH-sensitive behavior. In total, the obtained hydrogel drug-delivery systems are presented a proper effect versus stomach cancer in vitro and in vivo, and it can be used as candidates for controlled release of anticancer drugs in stomach with exalted remedial agents.