交联微球GMA/MMA的表面化学改性及卟啉在其上的固载化

采用悬浮聚合法,制备了甲基丙烯酸缩水甘油酯(GMA)与甲基丙烯酸甲酯(MMA)的交联共聚微球GMA/MMA。在此基础上,使用Brnsted酸对羟基苯甲醛(HBA)对交联微球进行了化学改性,通过环氧基团的开环反应,将HBA键合在交联微球表面,制得了化学改性微球HBA-GMA/MMA;重点考察了主要反应条件对改性反应的影响,表明采用极性较强的溶剂并升高温度有利于改性反应的进行。随后以微球HBA-GMA/MMA、溶液中的苯甲醛衍生物及吡咯为共反应物,使Adler反应在固-液界面上进行,实现了卟啉在交联微球GMA/MMA表面的同步合成与固载。     

在聚合物微球 GMA/MMA 表面同步合成与固载卟啉及固载化金属卟啉的催化氧化性能

 制备了甲基丙烯酸缩水甘油酯 (GMA) 与甲基丙烯酸甲酯 (MMA) 共聚微球 GMA/MMA, 并通过键合有对羟基苯甲醛 (HBA) 的改性微球 HBA-GMA/MMA 与苯甲醛 (或取代苯甲醛) 以及吡咯间的 Adler 反应, 实现了卟啉在共聚微球 GMA/MMA 表面的同步合成与固载, 制得了固载有苯基卟啉 (PP)、对氯苯基卟啉 (CPP)、对硝基苯基卟啉 (NPP) 的功能化微球 PP-GMA/MMA, CPP-GMA/MMA 和 NPP-GMA/MMA. 重点考察了影响卟啉同步合成与固载过程的因素. 制备了固载有钴卟啉的催化剂, 并以分子氧氧化乙苯为模型反应, 考察了催化剂的活性. 结果表明, 苯甲醛取代基的结构、催化剂的酸性和溶剂的极性对卟啉的同步合成与固载都有较大的影响; 钴卟啉催化剂对分子氧氧化乙苯反应具有较高的催化活性, 且当钴卟啉外环上含有强吸电子基团硝基时, 催化剂活性最高.     

含环氧基团的聚合物微球固载2,2,6,6-四甲基哌啶氮氧自由基催化剂的制备及其催化分子氧氧化苯甲醇

以甲基丙烯酸缩水甘油酯(GMA)为单体, 以乙二醇二甲基丙烯酸酯(EGDMA)为交联剂, 采用悬浮聚合法制得交联聚甲基丙烯酸缩水甘油酯(CPGMA)微球, 然后以4-羟基-2,2,6,6-四甲基哌啶氮氧自由基(4-OH-TEMPO)为试剂, 使CPGMA微球表面的环氧基团发生开环反应, 从而制得了TEMPO固载化微球TEMPO/CPGMA, 考察了制备条件对固载化反应的影响, 并采用多种方法对微球TEMPO/CPGMA进行了表征. 将微球TEMPO/CPGMA与CuCl组成共催化体系, 用于分子氧氧化苯甲醇, 考察了反应条件对催化体系性能的影响. 结果表明, 以含环氧基团的聚合物微球CPGMA为载体, 通过开环反应, 可成功地实现TEMPO的固载化, 开环反应属S_N2亲核取代反应, 适宜采用溶剂N,N''-二甲基甲酰胺和反应温度85℃. 非均相催化剂TEMPO/CPGMA与助催化剂CuCl构成共催化体系, 在室温、常压O₂条件下可高效地将苯甲醇氧化为苯甲醛, 产物选择性和产率分别为100%和90%. 主催化剂TEMPO与助催化剂CuCl适宜的摩尔比为1:1.2; 主催化剂适宜用量为0.90 g. 此外, TEMPO/CPGMA固体催化剂具有良好的循环使用性能.     

聚合物微球固载N-羟基邻苯二甲酰亚胺催化剂的制备及其催化氧化性能初探

首先采用悬浮聚合法,制备了甲基丙烯酸缩水甘油酯(GMA)和甲基丙烯酸甲酯(MMA)的交联聚合物微球(GMA/MMA),然后经过几步大分子反应在微球表面合成与固载了N-羟基邻苯二甲酰亚胺(NHPI),形成固载有NHPI的功能微球GMA/MMA-NHPI。采用红外光谱(FT-IR)及扫描电子显微镜(SEM)等方法对功能微球进行了表征。结果表明,以含环氧基团的GMA/MMA为载体,通过大分子反应可实现NHPI的合成与固载。GMA/MMA-NHPI与醋酸钴(Co(OAc)2)构成的共催化体系,在分子氧对环己烷和环己醇的氧化过程中,显示出良好的催化活性。     

在交联聚苯乙烯微球表面实现苯基卟啉的同步合成与固载

以键合有对羟基苯甲醛(HBA)的交联聚苯乙烯(CPS)微球HBA-CPS、苯甲醛和吡咯为反应物, 采用Adler方法, 实现了苯基卟啉(PP)在CPS表面的同步合成与固载, 制得了固载有苯基卟啉的微球PP-CPS. 研究了卟啉同步合成与固载过程的影响因素, 同时进行了微球PP-CPS与钴盐的配合反应, 制备了固载有钴卟啉(CoP)的功能微球CoP-CPS, 初步考察了其对分子氧氧化乙苯的催化活性. 实验结果表明, 在苯基卟啉同步合成与固载的反应过程中, 催化剂的酸性与溶剂的极性是两个主要的影响因素, 使用强极性溶剂与pKa在2.8~3.4范围的酸, 微球PP-CPS表面的苯基卟啉固载量高. 微球CoP-CPS对分子氧氧化乙苯的反应具有明显的催化活性.     

在CPS微球表面实现N-羟基邻苯二甲酰亚胺的同步合成与固载及固体催化剂催化氧化性能初探

通过分子设计的构思,仅通过两步大分子反应,便实现了N-羟基邻苯二甲酰亚胺(NHPI)在交联聚苯乙烯(CPS)微球表面的同步合成与固载,并制得了非均相催化剂微球CPS-NHPI。以氯化偏苯三酸酐(TMAC)为试剂、Lewis酸为催化剂,通过Friedel-Crafts酰基化反应,先将邻苯二甲酸酐(PA)基团键合在CPS微球表面,得到改性微球CPS-PA;再与盐酸羟胺进行酰亚胺反应,制备出固载有NHPI基团的非均相催化剂微球CPS-NHPI。重点研究了CPS微球表面发生Friedel-Crafts酰基化反应的影响因素。采用红外光谱(FT-IR)及扫描电子显微镜(SEM)等对微球CPS-NHPI进行表征,将微球CPS-NHPI分别用于分子氧氧化乙苯及环己烷两种烃类物质的氧化过程,初步考察了该微球的催化活性。研究结果表明,对于微球CPS与TMAC之间的FriedelCrafts酰基化反应,适宜的溶剂为氯仿与N,N-二甲基乙酰胺(DMAC)混合溶剂(氯仿与DMAC的体积比为7∶3),适宜的Lewis酸催化剂为SnCl4。初步探索实验表明,催化剂微球CPS-NHPI与Co(OAc)2所构成的共催化体系,在分子氧氧化乙苯及环己烷的催化氧化过程中,都表现出了良好的催化活性,温和条件下,反应35h时乙苯氧化为苯乙酮的转化率可达37%,反应30h时环己烷氧化为环己酮的转化率可达21%。     

接枝微粒PGMA／SiO2固载的金属卟啉仿生催化剂的制备

采用"接枝"法将甲基丙烯酸缩水甘油酯(GMA)接枝聚合到硅胶微粒表面,通过环氧键与羟基的开环成醚反应,进而将小分子的对羟基苯基卟啉化学键合在接枝微粒PGMA/SiO2表面,再与金属锰配位,从而制得了PGMA/SiO2固载的金属卟啉仿生催化剂(MnP-PGMA/SiO2);并用红外光谱法和原子吸收光谱法进行了表征;重点研究了对羟基苯基卟啉在接枝微粒PGMA/SiO2表面键合反应的规律;初步考察了MnP-PGMA/SiO2对分子氧氧化乙苯为苯乙酮的催化作用。实验结果表明:在键合反应中以4.5mL三乙胺为催化剂,在70℃下反应8h,可制得卟啉键合量为69.36μmol/g的键合微粒HPP-PGMA/SiO2;HPP-PGMA/SiO2与锰配位时,在64℃下反应8h,得到锰有效配位程度为92.34%的固体催化剂MnP-PGMA/SiO2。在催化分子氧氧化乙苯为苯乙酮的过程中,固体催化剂MnP-PGMA/SiO2具有高的催化活性。     

聚天冬酰胺衍生物对P(MMA-GMA-DVB)微球的修饰

用无皂乳液聚合法合成了不同交联剂含量(单体的20～50wt%)的表面带环氧基团的窄分散的P(MMA-GMA-DVB)(PMGD)复合微球,以L-天冬门酸为原料用磷酸催化溶剂法制备了聚琥珀酰亚胺(PSI),以N,N-二甲基甲酰胺为溶剂将PSI接枝到PMGD微球表面.元素分析结果证明,当微球中DVB的含量为40%时,微球表面修饰的PSI量最多.然后用乙二胺对微球表面剩余的PSI环进行开环,利用微球表面的氨基键合荧光素异硫氰酸荧光素(FITC),得到了荧光微球.     

硅胶固载化─（Lewis）酸催化剂的研究Ⅰ．硅胶固载化─四氯化钛复合物催化体系

以硅胶球为基质键合γ－ＧＯＰＳ并各接枝上具有络合功能的三种配体，邻位氨基吡啶、间酰氨基吡啶及对酰氨基吡啶，再和ＴｉＣｌ＿４络合成固载化的Ｌｅｗｉｓ酸催化剂，将这些催化剂进行缩醛、缩酮及酯化反应，有很好的催化活性，重复使用多次不失效．本文在合成此类催化剂的过程中利用热失重（ＴＧ）法及等离子光谱法（ＩＣＰ）等检测方法对合成此类催化剂的每一步进行跟踪检测，得到键合反应，开环反应及络合反应过程中的键合量，开环相量和ＴｉＣｌ＿４络合量的定量数据．对固载化催化剂表面的接枝量有所了解，从而可进一步检测此类催化剂的催化效应并得到一些启示．     

功能微球PEI-CPGMA的制备及其对胆红素的吸附特性

以乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,采用悬浮聚合法制备了平均粒径为100 μm的交联聚甲基丙烯酸缩水甘油酯(CPGMA)微球,然后通过胺基与环氧键之间的开环反应,将聚乙烯亚胺(PEI)偶合接枝在微球表面,制得了表面接枝PEI的功能微球PEI-CPGMA.研究了功能微球对胆红素的吸附性能,考察了接枝度、介质pH、离子强度等因素对微球吸附性能的影响.静态吸附实验结果表明:功能微球对胆红素具有强吸附能力,等温吸附满足Freundlich吸附方程,饱和吸附量可达14.1 mg/g;介质的pH对微球吸附性能有很大的影响,在近中性(pH=6)溶液中,接枝微球对胆红素的吸附能力最强,而在酸性与碱性溶液中吸附能力都比较弱;离子强度对吸附作用表现出微弱的增效作用;微球表面PEI的接枝度越高,吸附能力越强.     

季鏻盐型三相相转移催化剂的制备及其化学结构与相转移催化活性的关系

 使用两种 ω-氯代酰氯 (氯乙酰氯与氯丁酰氯) 对交联聚苯乙烯微球 (CPS) 进行 Friedel-Crafts 酰基化反应,使用 1,4-二氯甲氧基丁烷对 CPS 微球进行氯甲基化反应, 分别将可交换的氯引入 CPS 微球表面, 制备了化学改性的 CPS 微球. 然后使用三苯基膦对改性微球进行季鏻化反应, 制备了间隔臂 (spacer arm) 长度不同的三种季鏻 (QP) 盐型三相相转移催化剂 QP-CPS. 考察了主要反应条件对制备过程的影响, 并以氯化苄与乙酸钠合成乙酸苄酯的反应体系作为三相相转移催化的模型体系, 初步考察了 QP-CPS 的相转移催化活性,探索了催化剂结构与相转移催化活性的关系. 结果表明, 季鏻盐的化学稳定性较差,在制备过程中需控制反应时间与温度, 且宜选用极性较高的溶剂. 季鏻盐型三相相转移催化剂 QP-CPS 对乙酸苄酯的合成具有较高的催化活性, 在液-固-液之间可有效地实现反应物种乙酸根的转移. 与季铵盐 (QN) 型三相相转移催化剂 QN-CPS 相比, 季鏻盐型三相相转移催化剂 QP-CPS 具有更高的相转移催化活性. 间隔臂越长, QP-CPS 的相转移催化活性越高, QP-CPS 的亲水和亲油性能对相转移催化活性也有很大的影响.     

Surface modification of thermally expandable microspheres by grafting poly(glycidyl methacrylate) using ARGET ATRP

This study demonstrates the surface modification of thermally expandable core/shell microspheres by grafting glycidyl methacrylate (GMA) using activators regenerated by electron transfer (ARGET) ATRP. To retain the expansion properties it was essential to minimize the shear forces, use solvents compatible with the microspheres and keep the reaction times short (three hours or less). Using microspheres with hydroxyl groups on the surface, it was found that after converting these to α-bromo esters, GMA could be grafted by ARGET ATRP using only 50 ppm of copper catalyst in toluene at 30 °C. Decent control of the polymerization was achieved with PMDETA as ligand reaching PDIs of 1.4 for the solution polymerization of GMA. When microspheres were present, the polymerization was less controlled with higher PDIs. The epoxide groups of the grafted microspheres were hydrolyzed by HCl in THF providing a hydrophilic surface of the microsphere. The expansion property of the microspheres was studied after each reaction step by thermal mechanical analysis, and it was found that the expansion capacity was well preserved with only limited negative effect on the microspheres.     

ZnO@P(AA/MMA/GMA)@Fe3O4复合微球：制备及光催化性能

采用导向沉淀法在胺化的P(AA/MMA/GMA)@Fe3O4(MCM,其中AA为丙烯酸,MMA为甲基丙烯酸甲酯,GMA为甲基丙烯酸缩水甘油酯)微球表面负载ZnO粒子制备得到了ZnO@P(AA/MMA/GMA)@Fe3O4(ZPM)三层结构磁性复合微球。通过XRD、SEM、粒度分析、TGA及VSM等手段对ZPM微球进行表征,结果表明:ZPM微球平均粒径为1.38μm,ZnO负载量为13.02%,比饱和磁化强度为8.64 emu.g-1。同时研究了ZPM微球的光催化性能,以罗丹明B(RhB)为被降解物,微球对RhB的吸附效率为50.07%,催化降解效率可达93.40%。     

Surface modification of polymers. V. Biomaterial applications

Polyethylene films were surface grafted with glycidyl methacrylate (GMA) by UV irradiating the film for 5 min together with benzophenone. Poly(ethylene glycol) (PEG) was attached to the grafted surface through reaction with the epoxy groups. This yielded a surface which consisted of 95% PEG as measured with ESCA. The adsorption of human transferrin onto this film was significantly reduced as compared with a pure polyethylene film. Heparin was also reacted with a GMA grafted PE surface. ESCA showed that heparin was grafted to the surface, and in vitro blood clotting tests on the heparinized PE surface showed a reduced thrombus formation. GMA grafted polystyrene wells were reacted with carbohydrazide, to the formed carbohydrazide surface a rabbit antibody raised against mouse urinary protein (RaMUP) was covalently coupled. The RaMUP coupled surfaces was used in the detection of mouse urinary protein (MUP) at low concentrations (ca. 1 ng/mL) with an ELISA technique.     

Nanosphere formation in copolymerization of methyl methacrylate with poly(ethylene glycol) macromonomers

Polymeric nanospheres consisting of poly(methyl methacrylate) (PMMA) cores and poly(ethylene glycol) (PEG) branches on their surfaces were prepared by free radical copolymerization of methyl methacrylate (MMA) with PEG macromonomers in ethanol/water mixed solvents. PEG macromonomers having a methacryloyl (MMA‐PEG) and p‐vinylbenzyl (St‐PEG) end group were used. It has become clear that the obtained polymer dispersions form three kinds of states, particle dispersion (milky solution), clear solution, and gel/precipitation. It was found that the reaction parameters such as MMA concentration, molecular weight, and concentration of PEG macromonomers, and water content can affect nanosphere formation in a copolymerization system. The water volume fraction of mixed ethanol/water solvents affected the particle size of the nanospheres. These differences in the formation of nanospheres were due to the solvophilic/solvophobic balance between the copolymers and solvents during the self‐assembling process of the copolymers. The sizes of nanospheres can be controlled by varying concentration of PEG macromonomer and water content in solvents. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1811–1817, 2000     

Investigation of the thermal properties of glycidyl methacrylate–ethylene glycol dimethacrylate copolymeric microspheres modified by Diels–Alder reaction

Journal of Thermal Analysis and Calorimetry - The study describes the thermal properties of functional microspheres composed of glycidyl methacrylate (GMA) and crosslinking agent ethylene glycol...     

Direct synthesis of amphiphilic block copolymers from glycidyl methacrylate and poly(ethylene glycol) by cationic ring‐opening polymerization and supramolecular self‐assembly thereof

Amphiphilic block copolymers composed of a hydrophilic poly(ethylene glycol) (PEG) block and a hydrophobic poly(glycidyl methacrylate) (PGMA) block were synthesized through cationic ring‐opening polymerization with PEG as the precursor. The model reactions indicated that the reactivity of the epoxy groups was higher than that of the double bonds in the bifunctional monomer glycidyl methacrylate (GMA) under the cationic polymerization conditions. Through the control of the reaction time in the synthesis of block copolymer PEG‐b‐PGMA, a linear GMA block was obtained through the ring‐opening polymerization of epoxy groups, whereas the double bond in GMA remained unreacted. The results showed that the molecular weight of the PEG precursor had little influence on the grafting of GMA, and the PGMA blocks almost kept the same length, despite the difference of the PEG blocks. In addition, the PGMA blocks only consisted of several GMA units. The obtained amphiphilic PEG‐b‐PGMA block copolymers could form polymeric core–shell micelles by direct molecular self‐assembly in water. The crosslinking of the PGMA core of the PEG‐b‐PGMA micelles, induced by ultraviolet radiation and heat instead of crosslinking agents, greatly increased the stability of the micelles. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2038–2047, 2005     

聚对二氧环己酮/聚乙二醇两亲性聚合物共网络的合成与表征

以辛酸亚锡为催化剂,季戊四醇(PTOL)为引发剂,引发对二氧环己酮(PDO)单体开环聚合,合成了以PTOL为核的四臂聚对二氧环己酮(4s-PPDO).通过直接将4s-PPDO预聚物和聚乙二醇(PEG)于熔点以上、惰性气体保护下与偶联剂甲苯二异氰酸酯(TDI)交联共聚得到聚对二氧环己酮/聚乙二醇(PPDO-b-PEG)两亲性共网络聚合物(PPDO-PEG APCNs).研究了两亲性聚合物共网络结构、配比组成、溶剂种类等对聚合物溶胀率的影响,结果表明APCNs在不同类型的溶剂中表现出不同的溶胀行为,可以通过调节偶联剂的用量及PPDO/PEG的投料比来满足不同的实际需求.通过示差扫描量热分析(DSC)详细研究APCNs的结晶性能,证实交联反应降低APCNs的结晶度和结晶尺寸.