响应面法优化无溶剂体系磷脂酶A1催化酯化制备低聚甘油酯的研究

以工业油酸和低聚甘油为原料,经磷脂酶A1(Lecitase Ultra)催化酯化制备低聚脂肪酸甘油酯。利用响应面法优化实验条件,研究反应时间、反应温度、加酶量、加水量以及底物摩尔比值(工业油酸和低聚甘油摩尔比值)对其酯化率的影响。得出最佳反应条件为:反应温度45℃,加酶量1.6wt%(占底物总质量),加水量4wt%(占底物总质量),反应时间12h,底物摩尔比值为1:1。最佳条件下酯化反应平均酯化率可达到56.6%。采用HPLC-ESI质谱通过检测相对分子质量验证了部分低聚甘油酯产物的种类。     

低聚甘油合成方法的研究

以NaOH为催化剂,催化甘油合成聚甘油,通过红外光谱、高效液相色谱对反应产物进行定性、定量分析,考察了不同的反应条件对甘油聚合反应进程和产物组成的影响。     

Inhibition of influenza virus activity by multivalent glycoarchitectures with matched sizes

We describe the synthesis of a series of sialic acid‐conjugated, polyglycerol‐based nanoparticles with diameters in the range of 1–100 nm. Particle sizes were varied along with the degree of functionalization to match the corresponding virus size and receptor multiplicity in order to achieve maximum efficiency. To build up these architectures, we used biocompatible, hyperbranched polyglycerols as scaffolds and recently developed polyglycerol‐based nanogels, the sizes of which can be varied between 2–4 nm and 40–100 nm, respectively. We demonstrate here that such multivalent nanoparticles inhibit influenza A virus cell binding and fusion and consequently infectivity. The potential of multivalency is evident from larger particles showing very efficient inhibition of viral infection up to 80 %. Indeed, both the size of the nanoparticle and the amount of ligand density are important determinants of inhibition efficiency. The inhibitory activity of the tested polymeric nanoparticles drastically increased with size. Particles with similar dimensions to the virus (50–100 nm) are exceedingly effective. We also observed a saturation point in degree of surface functionalization (i.e. ligand density), above which inhibition was not significantly improved. Our study emphasizes the importance of matching particle sizes and ligand densities to mimic biological surfaces and improve interactions; this is a vital concept underlying multivalent interactions.     

Synthesis and characterization of novel polyglycerol hydrogels containing L‐lactic acid groups as pendant acidic substituents: pH‐Responsive polyglycerol‐based hydrogels

Novel pH‐responsive polyglycerol (PG)‐based hydrogels were successfully synthesized through the reaction of epichlorohydrin with L ‐lactic acid (LLA) in the presence of sodium hydroxide (NaOH), and cetyltrimethylammonium bromide as a phase transfer catalyst at room temperature, followed by hydrolysis, polymerization, and crosslinking reactions. The resultant gel was characterized by carbon nuclear magnetic resonance spectroscopy, X‐ray photoelectron spectroscopy, and Fourier transform infrared measurement, and it was found that incorporated LLA was bound to PG network as a pendant acidic substituent by the hydroxyl group of LLA (PGL gel). The PGL hydrogels with different LLA contents and equilibrium swelling ratios (ESRs) were prepared by changing the feed ratios of materials. The results determined by chemical titration showed that under the applied conditions the efficiency of introducing the carboxyl group into PG network was about 86% and the amount of LLA in the hydrogel reached to about 17 wt %. The swelling behavior of the hydrogels in different environmental mediums was investigated, and the results showed that the hydrogels are pH‐, ionic strength‐, and cationic charge‐responsive. The hydrogels also have the reversible swelling/deswelling properties. These pH‐responsive PG‐based hydrogels will have potential applications in biomedical and related areas. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

非离子表面活性剂十二烷基聚甘油醚的合成与性能研究

在碱催化作用下以十二烷基缩水甘油醚(AGE)与聚甘油反应合成了一种非离子表面活性剂十二烷基聚甘油醚,并研究了不同甘油聚合度(n)对产物表面化学性能的影响。结果显示,当n=2时,γcmc和cmc最低;n=10时,泡沫性能、钙皂分散性能和增溶性能最好;n=4时,乳化性能最好。     

聚甘油脂肪酸酯的合成及其整理性能研究

用甘油和各种脂肪酸为原料制得聚甘油和相应系列的聚甘油脂肪酸酯,并测试、表征了合成产品的基本性能。将合成产品调制成平滑整理剂对织物进行整理,分析、比较了不同聚合度、脂肪酸、整理剂浓度对织物平滑性能的影响,最终获得了平滑整理效果好的产品结构信息。     

New hyperbranched polyether containing cyclic carbonate groups as a toughening agent for epoxy resin

Hyperbranched polyglycerol containing terminal five-membered cyclic carbonate groups has been obtained by anionic polymerization of glycidol and then in the reaction of its terminal vicinal hydroxyl groups with dimethyl carbonate in the presence of potassium carbonate. The remaining OH groups of the polymer were protected in the reaction with acetic anhydride to reduce polymer hydrophilicity and increase miscibility with the epoxy resin. A strong decrease in viscosity was observed after esterification, from 73 to 3.6 Pa s. The product (HBPG 3) was used for modification of the bisphenol A based epoxy resin. The epoxide-cyclic carbonate compositions were cured using a polyamine hardener (TETA) in a one-step procedure. Thermal and mechanical properties of the cured compositions were characterized and compared with the parent epoxy resin. The optimal mechanical properties were obtained for the compositions containing HBPG 3 when phase separation takes place. The mechanical properties are discussed in terms of the morphology observed by SEM.     

Synthesis of a thioether modified hyperbranched polyglycerol and its template effect on fabrication of CdS and CdSe nanoparticles

A thioether‐containing hyperbranched polyglycerol (PG) was synthesized by a simple and effective two‐step reaction; first a part of the hydroxyls of PG was transformed to carbamates by the reaction with the highly reactive 2‐chloroethyl isocyanate, and then the chlorine group was S‐alkylated with HS(CH₂)_nOH (n = 2, 6, 11). The resulting PGs with various molecular weights were successfully used as template for synthesis of nanoscale cadmium chalcogenide quantum dots (QDs). It was found that the size of these QDs was dependent on the polymer template. Moreover, after solvent evaporation, the polymer was assembled into large cluster, and a variety of morphologies were formed by the cluster inside the QDs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3679–3684, 2006