N-苯基马来酰亚胺与苯乙烯共聚物乳液的研究

采用种子乳液聚合法制备了N-苯基马来酰亚胺(NPMI)与苯乙烯(St)共聚物乳液,讨论了单体配比对共聚物乳液的聚合稳定性、转化率、流变性、表面张力、粒径大小及分布的影响。结果表明:随着混合单体中NPMI含量的增加,NPMI与St混合单体的转化率降低,聚合物乳液的凝胶量增大,聚合稳定性减弱,黏度逐渐增加。所得共聚物乳液粒径为70~80nm,粒径分布均匀。     

温敏型水凝胶的制备及溶胀特性

采用N-异丙基丙烯酰胺(NIPA)与N-乙烯基-2-吡咯烷酮(NVP)为共聚单体,以N,N-亚甲基双丙烯酰胺(BIS)为交联剂,过硫酸钾(KPS)为引发剂,通过化学交联的方法在水溶液中制备出P(NIPA-co-NVP)共聚物水凝胶。分别探讨了单体配比、交联剂用量等实验条件对水凝胶的温敏特性和溶胀性能的影响。利用傅里叶红外(FT-IR)对共聚物水凝胶的结构进行了表征。通过实验可知:当交联剂BIS和引发剂KPS分别为单体用量的5%和0.8%,制备的水凝胶具有较高的转化率、较好的机械强度和共聚性质。共聚物水凝胶中NVP含量越高,溶胀率越大,升温时溶胀率下降程度越大,自然条件下脱水速率越快;BIS用量越大,溶胀率越小,保水率越高,需要更长时间达到溶胀平衡。     

双亲性氯化聚乙烯接枝共聚物的吸水膨胀性能

采用反相悬浮法制备了颗粒状接枝共聚物———氯化聚乙烯接枝丙烯酸(CPE-g-AA)、氯化聚乙烯接枝丙烯酰胺(CPE-g-AM)和氯化聚乙烯接枝混合单体丙烯酸、丙烯酰胺[CPE-g-(AA-AM)],并通过热压法制得接枝共聚物片材。考察了颗粒状接枝共聚物和接枝共聚物片材的吸水膨胀性能。结果表明,接枝共聚物的吸水性能与接枝单体的种类及其接枝率有关,相同接枝率的CPE-g-AA的吸水量比CPE-g-AM的大。当混和单体丙烯酸/丙烯酰胺的质量比为2/2时,所得接枝共聚物的抗盐性能最好。接枝共聚物片材可反复吸水膨胀,接枝率为62%的CPE-g-AA片材的二次吸水达到平衡时的吸水率和膨胀率分别为120%和41%。通过测定接枝共聚物的接触角表明,CPE-g-AA对水的润湿作用比CPE-g-AM明显。     

温度与pH敏感P(NIPAM-co-MAA)水凝胶的制备及性能研究

室温条件下,以安息香双甲醚作为光引发剂、N,N-亚甲基双丙烯酰胺为交联剂,在乙醇溶液中,采用紫外光照聚合的方法,合成了透明均质的聚(N-异丙基丙烯酰胺-co-甲基丙烯酸)共聚物水凝胶。用红外光谱和扫描电镜分析了水凝胶的结构,通过测定水凝胶的溶胀率和退涨率考察了单体、引发剂及交联剂用量对其性能的影响。通过p H敏感性测定,发现该共聚凝胶为阴离子型p H敏感水凝胶。在弱碱性溶液中有最高的溶胀率。     

AM与HEMA共聚制备水凝胶接触镜材料及其溶胀性能

采用丙烯酰胺(AM)与甲基丙烯酸β-羟乙酯(HEMA)进行本体共聚制备水凝胶接触镜材料,研究了水凝胶的溶胀性能及其温度和pH值敏感性。结果表明,引发剂过氧化苯甲酰(BPO)用量为反应单体总质量的0.3%、反应温度80℃,产物溶胀之后为无色透明的玻璃状水凝胶;共聚物水凝胶具有较好的pH值敏感性,水凝胶在酸性溶液中溶胀,在碱性溶液中收缩:含有AM的水凝胶,其pH值敏感性较大:随AM的含量增大,共聚物水凝胶的溶胀速度和饱和含水量增大,随温度升高,水凝胶的饱和含水量下降,共聚物水凝胶中AM的含量对其温度敏感性无显著影响:SEM照片显示,AM与HEMA共聚物存在均匀的纤维状结构,并且共聚物中AM的含量越大,这种纤维状结构越大、越明显。     

含木质素水凝胶的研究进展

综述了含木质素水凝胶的研究概况。含木质素水凝胶主要由三种方式制备:木质素或改性木质素直接交联;木质素与亲水性单体接枝,同时加交联剂交联;木质素以互穿或半互穿的形式引入水凝胶中。向水凝胶中引入木质素,可以使凝胶具有pH敏感和溶剂敏感性,或者使其具备吸附与富集金属离子的功能,或者改变温度敏感型水凝胶的最低临界溶解温度。     

双重响应性纳米凝胶的制备及其结构色调控

通过酰氯化反应成功合成了一种新型的弱酸性单体L-N-丙烯酰基苯丙氨酸(APhe),采用乳液沉淀共聚的方法将此单体与温敏性单体N-异丙基丙烯酰胺(NIPA)进行共聚,合成了共聚纳米凝胶P (NIPA-co-APhe)。利用红外光谱仪、TEM对制备样品的结构、形貌进行了测试表征,表征结果显示纳米凝胶呈球状并具有良好的单分散性,使用粒度分析仪对纳米凝胶进行分析,发现纳米凝胶具有良好的温敏性及pH敏感性。使用光纤光谱仪对其结构色进行了表征,发现可以通过调节单体配比、pH值来调节纳米凝胶的结构色。进一步发现,新型P (NIPA-co-APhe)纳米凝胶发生相变后,依然能保持亮丽的结构色。     

碳纳米管接枝共聚物合成及结构研究

碳纳米管的修饰和功能化是制备碳纳米材料改性聚合物基复合材料的必要前提。通过对碳纳米管的羧酸化、酰氯化和醇化等一系列处理过程,分别在碳纳米管表面接枝—COOH、—COCl、—OH等官能团,经与丙烯腈单体反应而生成碳纳米管接枝共聚物。     

带β-环糊精侧基水凝胶的制备与性能研究

用顺丁烯二酸酐（MAH）对β-环糊精（β-CD）进行化学改性制备丁烯二酸单酯化β-环糊精单体（MAH-β-CD）。用氧化还原自由基引发单体MAH-β-CD、丙烯酰胺（AM）以及丙烯磺酸钠（SAS）共聚,合成水凝胶,用红外光谱对产物结构表征。溶胀研究结果表明该水凝胶具有良好的温度、pH敏感性。     

聚乙二醇/丙烯酸共聚水凝胶的制备及pH敏感性研究

采用热引发反应制备了聚乙二醇(PEG)／丙烯酸(AAc)共聚物水凝胶,研究了PEG与AAc比例、交联剂、引发剂含量及反应时间等因素对反应转化率和不同pH缓冲液对水凝胶溶胀比的影响。结果发现PEG／AAc配比为(3：7)～(4：6)之间时,凝胶转化率较大;引发剂、交联剂含量分别为PEG和AAc总含量的0．5％和0．4％时,反应时间为5h,凝胶转化率较高;PEG：AAc为6：4时,水凝胶具有较明显的pH敏感性。     

一种新型壳聚糖/聚乙二醇丙烯酸酯复合水凝胶制备与性能研究

用天然壳聚糖接枝环氧聚乙二醇单甲醚和丙烯酰氯制备了大分子单体,采用核磁共振对合成单体进行了分析表征。合成的单体在光引发条件下制备了壳聚糖类大分子单体/聚乙二醇丙烯酸酯(PEGDA)复合水凝胶,研究了接枝度对该凝胶溶胀度、粘弹性、失重率的影响,电镜扫描对合成单体和水凝胶形态进行了表征。结果表明:壳聚糖上环氧聚乙二醇单甲醚和丙烯酰氯接枝率分别为16%和15%,所制备的复合水凝胶随着丙烯酰氯接枝度的提高,溶胀度、失重率逐渐降低。     

超支化聚(胺-酯)-丙烯酸共聚物的合成

利用端单羟基超支化聚(胺-酯)与丙烯酰氯反应,制备了端基为双键的超支化聚(胺-酯)大分子单体(cHPAE),用该大分子单体与丙烯酸发生共聚合,合成了超支化聚(胺-酯)-聚丙烯酸共聚物(HPAE-co-AA),利用FTIR和1HNMR对大分子单体结构进行了表征,研究了反应条件对共聚产物分子量的影响.结果表明:共聚反应溶剂...     

铕(III)三元活性配合物/丙烯酸凝胶的制备

以氧化铕(Eu2O3)、邻菲罗啉(phen)和丙烯酸(AA)为原料,制备了含铕(III)三元活性配合物Eu(AA)3phen,与丙烯酸-丙烯酰胺凝胶体系进行UV共聚,制备了含铕水凝胶。研究了凝胶中Eu(AA)3phen含量对其吸水性、温敏性及荧光性能的影响,同时探讨了温度及溶胀时间对其荧光性能的影响。结果表明,随Eu(AA)3phen含量的增加,凝胶吸水率先增加后减少,荧光强度逐渐增强;对于特定的凝胶体系,其12 h溶胀度随温度增加而增加,凝胶的荧光强度随溶胀时间和温度增加而减弱。当Eu(AA)3phen的添加量为3.5%时,凝胶综合性能最佳:平衡溶胀度为631 g/g,4 h内吸水率达90%以上,荧光强度为175 a.u.。所研制的水凝胶在吸水及荧光性能方面对温度均具有良好的响应性。     

Synthesis and characterization of cholic acid‐containing biodegradable hydrogels by photoinduced copolymerization

A cholic acid (CA)‐containing biodegradable hydrogel (PLA‐PEG‐PLA‐co‐MACAH) was synthesized from the photoinduced copolymerization of a CA‐modified methacrylate monomer (MACAH), bearing a spacer of hexane‐1,6‐diol spacer between the methacryloyl and the cholanoate moieties, and a macromonomer (PLA‐PEG‐PLA‐DA), bearing two acryloyl end groups derived from a poly(lactic acid)‐b‐poly(ethylene glycol)‐b‐poly(lactic acid) triblock copolymer. The structure of MACAH was confirmed by FTIR, ¹H‐NMR, and MS. The hydrogel PLA‐PEG‐PLA‐co‐MACAH was characterized by scanning electron microscopy and X‐ray diffraction. The experiment results showed that the swelling ratios of the hydrogels decreased with the increase of the CA fraction. The investigation on the in vitro degradation of the hydrogel showed that the CA‐containing hydrogels degraded much slower than the hydrogels without CA component. The bioactivity of the synthesized hydrogels was assessed by the simulated body fluid method. The observed formation of hydroxyapatite on the scaffold of the hydrogels indicated that the hydrogels possess good bioactivity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of block comb‐like copolymers P(A‐MPEO)‐block‐PSt

Amphiphilic block comb‐shaped copolymers, poly[poly(ethylene oxide) methyl ether acrylate]‐block‐polystyrene [P(A‐MPEO)‐block‐PSt] with PSt as a handle, were successfully synthesized via a macromonomer technique. The reaction of MPEO with acryloyl chloride yielded a macromonomer, A‐MPEO. The macroinitiator PSt capped with the dithiobenzoate group (PSt‐SC(S)Ph) was prepared by reversible addition–fragmentation transfer (RAFT) polymerization of styrene in the presence of benzyl dithiobenzoate, and used as macroinitiator in the controlled radical block copolymerization of A‐MPEO at room temperature under ⁶⁰Co irradiation. After the unreacted macromonomer A‐MPEO had been removed by washing with hot saturated saline water, block comb‐shaped copolymers were obtained. Their structure was characterized by ¹H NMR spectroscopy and gel permeation chromatography. The phase transition and self‐assembling behaviour were investigated by atomic force microscope and differential scanning calorimetry. Copyright © 2004 Society of Chemical Industry     

亚微米级复合材料微粒合成研究

在乙醇-水混合溶剂中,用过硫酸钾(KPS)作为引发剂,通过乳液聚合作用来合成直径为375nm的聚苯乙烯(PSt)微球,并作为种子用于种子乳液聚合.用PEGm大分子单体作为稳定剂、偶氮二异丁腈作为引发剂,采用种子乳液聚合法,聚合苯乙烯和丙烯腈,制得特殊形态的亚微米尺寸的PEGm接枝共聚复合颗粒PEGm-g-PSAN.扫描电子显微镜(SEM)显示苯乙烯和丙烯腈同时促成了特殊形态.苯乙烯和丙烯腈的浓度、总单体浓度、引发剂类型和单体加入方式显著影响复合聚合物颗粒的形态.     

反应介质对催化链转移聚合反应的影响探究

采用催化链转移聚合法制备得到了端基带双键的聚甲基丙烯酸甲酯(PMMA)大分子单体,通过红外吸收光谱(FT-IR)、核磁共振氢谱(1HNMR)对大分子单体的结构进行了表征,并用凝胶渗透色谱法(GPC)测定了大分子单体的分子量及分子量分布;首次利用碘值法测定了大分子单体的双键含量。实验过程中考察了反应介质及其含量对大分子单体的分子量的影响,结果表明由于催化链转移剂与反应溶剂的络合作用,大分子单体的数均分子量随溶剂含量的增加而变大。     

Silicone hydrogels based on a novel amphiphilic poly(2‐methyl‐2‐oxazoline)‐b‐poly(dimethyl siloxane) copolymer

A novel amphiphilic hydrogel based on poly(2‐methyl‐2‐oxazoline)‐b‐poly(dimethyl siloxane) (PMeOx–PDMS) block copolymer was developed. First of all, PMeOx–PDMS macromonomer was synthesized by coupling mono‐hydroxylated PMeOx with PDMS followed by end‐capping with methacrylate group. The structures of each step were characterized by NMR and titration. After that, silicone hydrogels were prepared by UV‐initiated copolymerization of PMeOx–PDMS macromonomer with monomers such as 2‐hydroxyethyl methacrylate in the presence of a crosslinker. Measurements of the hydrogels' water contact angle, equilibrium water content, and tensile properties showed that the hydrogels possessed better hydrophilic surface, higher water content, and better ion permeability with the increase of the content of the macromonomer PMeOx–PDMS. Meanwhile, the tensile strength and Young's modulus of the hydrogels decreased slightly. Protein adsorption tests showed that the hydrogels had strong antifouling ability after the incorporation of PMeOx. This newly described hydrogel demonstrated attractive properties to serve as ophthalmic biomaterial. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39867.     

Bulk and emulsion copolymerizations of n-butyl acrylate and poly(methyl methacrylate) macromonomer

Bulk and emulsion copolymerizations of an ω-unsaturated poly(methyl methacrylate) (PMMA) macromonomer with n-butyl acrylate (n-BA) were investigated. The reactivity of PMMA macromonomer in bulk copolymerization with n-BA was found to be lower than that of methyl methacrylate monomer with n-BA. The incorporation of PMMA macromonomer into poly(butyl acrylate) (PBA) latex particles by miniemulsion copolymerization was proved by high performance liquid chromatography-silica adsorption spectroscopy. Dynamic mechanical studies showed that PMMA macromonomer was grafted to the PBA backbone, and the degree of grafting increased as the ratio of PMMA macromonomer to n-BA increased. Microphase separation of the PMMA macromonomer grafts was observed at higher ratio of macromonomer (higher or equal to 10% weight of macromonomer based on total polymer phase). The n-BA/PMMA macromonomer copolymer behaved completely differently from the physical blend of PBA and PMMA macromonomer particles of the same composition. © 1996 John Wiley & Sons, Inc.     

Preparation of micron-size monodisperse poly(methyl methacrylate) particles using poly(2-oxazoline) macromonomer

Micron-size monodisperse poly(methyl methacrylate) particles were prepared by dispersion copolymerization of methyl methacrylate with a hydrophilic poly(2-oxazoline) macromonomer in an aqueous methanol solution. The macromonomer acted as a comonomer as well as a stabilizer. As the macromonomer concentration increased, the diameter of the particles decreased. The macromonomer with higher molecular weight, or with more hydrophilic nature, stabilized the particles more effectively The diameter of the particles was dependent on the initiator concentration. Under the conditions giving monodisperse particles, the particle volume increased linearly with the yield of the particles and the particle number was almost constant during the copolymerization. From ESCA analysis of the particle surface, poly(2-oxazoline) chains were enriched on the surface.