合成聚乙烯基苯甲酸树脂的研究(Ⅱ)——由氯甲基化交联聚苯乙烯树脂按二步法合成

用两种二步法将交联度6％的大孔氯甲基化聚苯乙烯树脂制成了聚乙烯基苯甲酸树脂,产品氯含量均为零。     

LDPE-AA两步法气相光接枝体系交联特征的研究

研究了以二苯甲酮为光引发剂 ,L DPE两步法气相光接枝丙稀酸反应体系的交联特征 ;考察了光照条件、反应温度及光引发剂含量对交联度的影响 ,发现并讨论了接枝反应对交联的促进作用 ,探讨了产生这种促进作用的机理。     

新型羧甲基壳聚糖水凝胶流变性能,药物释放及细胞相容性研究

羧甲基壳聚糖含有丰富的羧基和氨基, 通过1-乙基-(3-二甲基氨基丙基)碳二亚胺盐酸盐(EDC)和N-羟基琥珀酰亚胺(NHS)共催化交联羧甲基壳聚糖形成新型水凝胶. 调节EDC/NHS用量, 制备不同交联度的羧甲基壳聚糖水凝胶(CMCS hydrogels). 研究水凝胶的流变行为, 结果表明, 高交联度的水凝胶具有较好的弹性形变能力, 较高的储存模量, 这是因为随着交联度的升高, 羧甲基壳聚糖水凝胶化学交联网络结构趋于完善. 以胸腺五肽(TP-5)为模型药物, 初步评价CMCS水凝胶药物释放行为, 结果表明水凝胶交联度越高, 胸腺五肽释放速度越慢. MTT法初步评价了水凝胶细胞毒性, 细胞形态和细胞相对增值速率, 结果表明水凝胶毒性很低. 由此可见, 水凝胶具有良好的生物相容性, 在药物缓释和组织工程领域具有广阔的应用前景.     

新型羧甲基壳聚糖水凝胶的合成与表征

通过1-乙基-(3-二甲基氨基丙基)碳二亚胺盐酸盐(EDC)/N-羟基琥珀酰亚胺(NHS)催化体系使羧甲基壳聚糖(CMCS)交联,制备了新型羧甲基壳聚糖水凝胶.探讨了EDC用量和EDC/NHS质量比对水凝胶特性的影响.CMCS水凝胶具有pH响应特性,在等电位点溶胀率最小.降解实验结果表明,水凝胶浸泡在磷酸盐缓冲溶液中,10 d失重率在15%~45%之间,主要是未交联部分溶解所致.而浸泡在含有0.2 mg/mL溶菌酶的磷酸盐缓冲溶液中,低交联度水凝胶80 h基本降解,高交联度水凝胶不易降解.初步研究了CMCS水凝胶包埋牛血清白蛋白(BSA)的释放行为.     

线形多嵌段聚氨酯的合成与结构研究

本文用溶液二步法合成了分别以聚酸、聚酯为软段的线形多嵌段聚氨酯，经抽提证明该弹性体内没有产生交联．用核磁共振（NMR）、红外光谱（FTIR）、差示扫描量热法（DSC）等手段对其进行表征，计算得到弹性体中硬段的百分含量，并就弹性体的热塑弹性作了深入的探讨。     

壳聚糖与聚乙二醇交联水凝胶研究

研究对壳聚糖(CS)进行化学修饰得到了不同丙烯酰基取代度(1.03%,3.55%和5.21%)的丙烯酰化羟丙基壳聚糖(AHCS);通过自由基引发反应,AHCS与聚乙二醇二丙烯酸酯(PEGDA)交联得到壳聚糖(CS)与聚乙二醇(PEG)为主体的交联水凝胶。通过SEM观察其为通透性良好的多孔性支架材料。水凝胶的溶胶含量和溶胀度随丙烯酰基取代度的增加而降低,水凝胶中壳聚糖的降解速率也随丙烯酰基取代度的升高而降低。对于同一取代度的交联水凝胶,其在酸性和碱性条件下的溶胀度大于中性环境。细胞试验表明,壳聚糖与聚乙二醇交联水凝胶具有良好的生物相容性。     

紫外光共聚交联制备GelMA/PEGDA水凝胶

为避免物理交联明胶基水凝胶的热不稳定性,以及化学方法交联明胶基水凝胶存在的毒性,本文采用丙烯酰化的方法将甲基丙烯酸酐(MA)与明胶反应,在明胶分子链上引入双键结构,并且实现了紫外光照射引发甲基丙烯酰胺基明胶(GelMA)与聚乙二醇双丙烯酸酯(PEGDA)共聚交联制备水凝胶。研究了不同的MA加入量对明胶修饰度的影响,并对GelMA/PEGDA交联水凝胶理化性质进行了测试和分析。结果表明:体系中PEGDA含量增加,能释放更多的自由基,增加交联反应的活性和程度,使水凝胶形成更加致密的三维网络结构。并且GelMA/PEGDA交联水凝胶在37℃比GelMA交联水凝胶更加稳定。GelMA/PEGDA交联水凝胶将来有望成为组织工程的支架材料。     

PVA/PVP共混交联膜的渗透蒸发分离性质(Ⅰ)

研究了4,4'-双叠氮芪-2,2'-二磺酸钠和戊二醛对聚乙烯吡咯烷酮(PVP)、聚乙烯醇(PVA)共混膜的交联及交联对共混膜分离恒沸点附近的乙醇/水混合物的影响.结果表明,膜的分离性质随着膜中PVP含量的增加而改变;采用混合型交联剂对PVA/PVP共混膜交联能明显改善膜的选择性.     

钙离子室温交联聚丙烯酸酯无皂水溶胶的研究

研究了Ca^2 聚丙烯酸酯无皂水溶胶交联乳液的制备条件，考察了交联温度、交联剂用量对涂膜性能的影响。结果表明Ca^2 加入无皂水溶胶中的最低温度为40℃，交联反应于室温下即完全发生，交联膜具有较好的耐热、耐水性能。用TEM以及电导滴定对交联机理进行了初步探讨，发现交联反应主要发生在胶乳表面．COO^-与Ca^2 之间。     

锆螯合物交联丙烯酸酯共聚物无皂水溶胶的研究Ⅰ丙烯酸酯三元共聚物合成条件对无皂水溶胶性能的影响

三乙醇胺螯合锆烷氧化物;交联反应;锆螯合物交联丙烯酸酯共聚物无皂水溶胶的研究 Ⅱ锆螯合物与丙烯酸酯三元共聚物无皂水溶胶的交联反应     

The delayed crosslinking amphiphilic polymer gel system based on multiple emulsion for in-depth profile control

Delayed crosslinking polymer gel systems are widely used in-depth profile control technology for water production control. In this paper, an amphiphilic polymer P(AM-NaA-DDAM) was synthesized by a free radical micellar polymerization method and a delayed crosslinking amphiphilic polymer gel system was prepared based on multiple emulsion of W₁/O/W₂ emulsion which was prepared by a two-step emulsification method. The optimized formulation of amphiphilic polymer gel systems is: 0.15% P(AM-NaA-DDAM), 0.3% methenamine, 0.02% resorcinol, and 0.3% citric acid. The delayed gelation time of the delayed crosslinking amphiphilic polymer gel system is closely related to the stability of the W₁/O emulsion. By using multiple emulsion delayed crosslinking method, the delayed crosslinking amphiphilic polymer gel system with diesel as the oil phase can delay the gelation time up to 168 hours.     

单一化学交联与物理化学复合交联高吸油树脂的比较

提出在单一化学交联吸油树脂中引入物理交联的设想，并采用悬浮聚合法了单一化学交联和物理－化学复合交联的聚丙烯酸酯系高吸油树脂，对两种不同树脂的吸油速率，低亲油性单体树脂的吸油性能，最佳单体配比以及化学交联剂含量的影响进行了比较，结果表明物理交联的引入加快了树脂的吸油速率，提高低亲油性单体树脂的吸油能力，并且还使最佳单体配比中低亲油性单体含量增加，同时表明部分物理交联吸油树脂有一最佳化学交联剂含量区。     

Mono-dispersed cross-linked polystyrene micro-spheres prepared by seed swelling polymerization method

A two-step swelling procedure was adopted to synthesize mono-dispersed and highly cross-linked poly (St-divinylbenzene) particles with PSt micro-spheres (1.80 μm in diameter). The PSt micro-spheres were prepared by a dispersion polymerization method and used as seeds. The effects of monomer concentration, ratio of ethanol to water, swelling reagents, crosslinking reagents, swelling temperature and agitation speed on particle size were investigated in detail. The morphologies and size distributions of these micro-spheres were examined by SEM and particle size analysis (PSA). The T _g of the micro-spheres was measured by DSC. The results indicate that the particles (6.20 μm in diameter) exhibit excellent mono dispersed property and high crosslinking degree when the concentration of the swelling reagent was 25%, the concentration of the crosslinking reagents was 23%, the swelling temperature was 30°C and the stirring speed was 150 r/min. __________ Translated from Chinese Journal of Applied Chemistry, 2007, 24(11): 1289–1294     

Characterization and Optimization of Injectable In Situ Crosslinked Chitosan-Genipin Hydrogels

In recent years, there has been an increased interest in injectable, in situ crosslinking hydrogels due to their minimally invasive application and ability to conform to their environment. Current in situ crosslinking chitosan hydrogels are either mechanically robust with poor biocompatibility and limited biodegradation due to toxic crosslinking agents or the hydrogels are mechanically weak and undergo biodegradation too rapidly due to insufficient crosslinking. Herein, the authors developed and characterized a thermally-driven, injectable chitosan-genipin hydrogel capable of in situ crosslinking at 37 °C that is mechanically robust, biodegradable, and maintain high biocompatibility. The natural crosslinker genipin is utilized as a thermally-driven, non-toxic crosslinking agent. The chitosan-genipin hydrogel's crosslinking kinetics, injectability, viscoelasticity, swelling and pH response, and biocompatibility against human keratinocyte cells are characterized. The developed chitosan-genipin hydrogels are successfully crosslinked at 37 °C, demonstrating temperature sensitivity. The hydrogels maintained a high percentage of swelling over several weeks before degrading in biologically relevant environments, demonstrating mechanical stability while remaining biodegradable. Long-term cell viability studies demonstrated that chitosan-genipin hydrogels have excellent biocompatibility over 7 days, including during the hydrogel crosslinking phase. Overall, these findings support the development of an injectable, in situ crosslinking chitosan-genipin hydrogel for minimally invasive biomedical applications.     

热可逆共价交联氯化聚乙烯的制备和性能

以双环戊二烯二羧酸钾 [DCPD(COOK) 2 ]为交联剂 ,通过共混反应法制得了共价交联的氯化聚乙烯(CPE)热塑性弹性体 (TPE) ,研究了共混反应条件 (温度、时间及交联剂用量等 )对TPE物性的影响 .反应溶解性和IR测定数据证明 ,DCPD(COOK) 2 与CPE分子链上的活性氯反应形成共价酯键而交联 ;物性测定数据表明 ,交联CPE的主要力学性能接近CPE常规硫化胶 ,不同的是该交联聚合物具备可塑性 ,经反复加工三次后 ,其力学性能还略有提高     

With radiation crosslinking of engineering plastics into the next millennium

Much basic research has been done on the crosslinking behaviour of so-called “engineering plastics”. Up to now the industrial conversion to actual manufacture of multifunctional electronic components has gained ever increasing importance in the plastics industry and will continue to do so in the coming years. Examples of this are SMD (surface mounted device) technology, and 3D-MID (3-dimensional moulded interconnected devices) technology. These techniques require materials with high short-term temperature stability. In this paper it will be discussed which engineering plastics are significant for the radiation crosslinking process, for both technical and commercial reasons. The main topics will be the crosslinking behaviour of Polybutylenterephthalate (PBT) and Polyamide (PA). The importance and the challenges to the irradiation industry, as well as practical applications, will be shown.     

Facile Tailoring of Structures for Controlled Release of Paracetamol from Sustainable Lignin Derived Platforms

Nowadays, sustainable materials are receiving significant attention due to the fact that they will be crucial for the development of the next generation of products and devices. In the present work, hydrogels have been successfully synthesized using lignin which is non-valorized biopolymer from the paper industry. Hydrogels were prepared via crosslinking with Poly(ethylene) glycol diglycidyl ether (PEGDGE). Different crosslinker ratios were used to determine their influence on the structural and chemical properties of the resulting hydrogels. It has been found that pore size was reduced by increasing crosslinker amount. The greater crosslinking density increased the swelling capacity of the hydrogels due to the presence of more hydrophilic groups in the hydrogel network. Paracetamol release test showed higher drug diffusion for hydrogels produced with a ratio lignin:PEGDGE 1:1. The obtained results demonstrate that the proposed approach is a promising route to utilize lignocellulose waste for producing porous materials for advanced biomedical applications in the pharmacy industry.     

丙烯酸乙酯/烯丙基缩水甘油醚共聚物的热可逆共价交联

研究了双环戊二烯基二羧酸及其铵盐对丙烯酸乙酯 /烯丙基缩水甘油醚共聚物的交联反应 ,对比了二者的交联速度 .用DSC评价了它们的热可逆转化行为 .制得了热可逆部分达 79 7%的共价交联环氧型丙烯酸酯橡胶     

阴离子型淀粉微球的合成及性能研究

本文以淀粉或淀粉衍生物为原料，ＰＯＣｌ３为交联剂，采用逆相悬浮交聚合技术合成了阴离子淀粉微球。以淀粉为基质中性微球不原料，用Ｎａ３Ｐ３Ｏ９作交联剂进行二次交联和阴离子化，得到另一种阴离子型淀粉微球，研究了两种微球的表观形态，粒径分布、溶胀性和吸附载药性能。     

CHARACTERIZATION OF RADIATION CROSSLINKING DENSITY OF F-40

In this paper, radiation-induced crosslinking mechanism and characterization of the crosslinking density of F-40 and F-4 by X-ray photoelectron spectroscopy (XPS) have been studied. The dose of gelation of F-40 obtained from XPS is 4.1×10~4 Gy. It is found that crosslinking density is the largest in the range of certain dose for F-40 and F-4.