P(MMA-co-MAh)-g-mPEG的合成及环境敏感性

采用偶合接枝法在甲基丙烯酸甲酯(MMA)和马来酸酐(MAh)无规共聚物上接枝不同含量的聚乙二醇单甲醚(mPEG), 合成具有pH敏感和温度敏感的两亲接枝共聚物P(MMA-co-MAh)-g-mPEG, 并对其进行了红外光谱和核磁共振波谱表征. 通过紫外-可见分光光度计测量了接枝共聚物水溶液的透光率, 结果表明, 接枝聚合物的水溶液呈现低临界溶解温度(LCST), 其LCST值对环境pH值和无机盐等因素敏感, 并可通过控制亲水侧链含量来调节.     

Synthesis and Micellar Behavior of DL-lactide-gelatin Copolymers as Amphiphilic and Biodegradable Materials

A series of novel biodegradable polymers, graft copolymers of D,L-lactide on gelatin, were designed and synthesized to overcome the shortcomings of gelatin and polylactide(PLA) biomaterials. The copolymers were characterized by nitrogen analysis, IR, 1H-NMR and thermal analysis. The amphiphilic properties of these copolymers were also investigated.     

Preparation and characterization of copolymers of chloroprene and methyl methacrylate

The preparation of chloroprene–methyl methacrylate copolymers in the presence of Lewis acids (Et_1.5AlCl_1.5) in hydrocarbon solvent and the effect of Lewis acids concentration on copolymer composition are described. ¹³C NMR spectra were obtained on these copolymers. In samples of high MMA content, tactic placements of MMA were observed as well as several different kinds of sequences for chloroprene and MMA. In samples of low MMA content, no tactic placements of MMA were found but several different kinds of chloroprene sequences were observed. From the analysis of the ¹³C NMR spectra of the different copolymers examined, it is apparent that all the various kinds of chloroprene sequences in these copolymers can be determined.     

Synthesis and characterization of novel poly（aryl ether sulfone ketone）s containing phthalazinone and biphenyl moieties

A novel series of poly（aryl ether sulfone ketone）s （PPESKs） containing phthalazinone and biphenyl moieties were prepared by two-step nucleophilic polycondensation reaction. The ^-Mw values of these copolymers were between 38,330 and 67,900. The glass transition temperatures （Tg） and 5% decomposition temperatures were ranged in 253-269 ℃ and 488-500 ℃, respectively, The structures of these copolymers were confirmed by FT-IR and ^1H NMR. Moreover, all the resultant copolymers were amorphous determined by wide angle X-ray diffraction （WAXD）.     

Synthesis and characterization of conjugated diblock copolymers

This paper reports the synthesis and characterization of a new class of diblock copolymers (co-oligomers), rod-rod conjugated diblock copolymers. A general synthetic strategy is outlined, and the structures of the copolymers (oligothiophene-co-oligophenylenevinylene) are fully characterized. It was found that these copolymers exhibit efficient intramolecular energy transfer. An interesting self-assembly ability of these rod--rod copolymers was also revealed.     

Synthesis and surface properties of fluorinated block copolymers containing sulfonic groups

A series of fluorinated block copolymers with different fluorinated block lengths and compositions were synthesized by atom transfer radical polymerization (ATRP), and then the block copolymers containing sulfonic groups with various sulfonation levels were successfully prepared further via a sulfonation reaction. These well‐defined block copolymers were characterized by means of Fourier transform infrared (FTIR), ¹H‐nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The surface activities of the fluorinated block copolymers containing sulfonic groups in N‐methyl pyrrolidone solution and the surface properties of the films prepared from such a solution were examined, and the experimental results showed that the fluorinated block copolymers exhibited a high surface activity in solution and quite a low solid surface energy of films, even though they contain hydrophilic sulfonic groups. The critical surface tensions of these copolymers were estimated and were comparable to that of polytetrafluoroethylene. Even more interestingly, the surface activities of the block copolymers containing sulfonic groups or sodium sulfonate groups in aqueous solution were also measured. It was found that the surface activity in aqueous solution was weaker than that in N‐methyl pyrrolidone solution and depended on both the length of the fluorinated block and the sulfonation level of the block copolymers. The surface properties of the films prepared from the block copolymers in aqueous solution were tested, and most of these films exhibited a hydrophilic surface property. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4809–4819, 2004     

Head-to-head vinyl polymers. IV. Preparation and characterization of equimolar head-to-head copolymers of acrylic acid and its esters

The alternating copolymer of ethylene with maleic anhydride was esterified with a number of aliphatic alcohols to yield its monoesters, which correspond structurally to equimolar (1:1) head-to-head (h-h) copolymers of acrylic acid with alkyl acrylates. In addition, they were methylated with diazomethane to 1:1 h-h copolymers of methyl acrylate with alkyl acrylates. For comparison the 1:1 head-to-tail (h-t) copolymers of methyl acrylate with alkyl acrylates were prepared by radical copolymerizations. Some chemical, physical, and thermal properties of these 1:1 h-h and h-t copolymers were evaluated and compared. The softening and glass transition temperatures of the 1:1 h-h copolymers were somewhat higher than those of the corresponding 1:1 h-t copolymers, which indicated that the h-h replacements made the polymer chain stiffer and less flexible. The 1:1 h-h copolymers were also observed to degrade thermally at somewhat higher temperatures and with higher rates than the 1:1 h-t copolymers. The ratio of alcohol to monomer found in the pyrolysis products was higher for the 1:1 h-h than for its respective 1:1 h-t copolymer.     

Oxidation of Hydroquinone By (N-Vinylpyrrolidone)-(4-Vinylpyridine) Block and Graft Copolymers

ABSTRACT

A-B Type block copolymer of N-vinylpyrrolidone (NVP) and 4-vinylpyridine (VPy) [poly(NVP-b-VPy) and graft copolymers of VPy onto copolymers of NVP with 4-vinylbenzyl N,N-diethyldithiocarbamate (VBDC) [poly(NVP-g-VPy) were synthesized by the iniferter method. the compatibility between NVP and VPy units in the copolymers was evaluated from the glass transition temperature of these copolymers. Hydroquinone was then oxidized by the synthesized NVP-VPy copolymers-Cu(II) complex catalysts. the influence of the distribution of each monomer unit in copolymers on the catalytic activity was studied by comparing the activity of these copolymers. the catalytic activity of these copolymers increased in the order: NVP-VPy blend polymer, poly(NVP-b-VPy), poly(NVP-g-VPy), random copolymer [poly(NVP-ran-VPy)]. This order parallels the compatibility between NVP units and VPy units in these copolymers.     

含羧基的含氟嵌段共聚物的合成及表面性能研究

利用原子转移自由基聚合反应以及随后的大分子链中叔丁酯基团的水解反应,合成了一系列具有不同含氟量和羧基含量的二嵌段共聚物,并分别通过GPC, ¹H NMR和FT-IR对共聚物的组成和结构进行了表征.进一步考察了这些含羧基或羧酸钠基团的含氟嵌段共聚物在吡咯烷酮或水中的溶解性能、临界胶束浓度、表面活性、达到饱和吸附时每个分子在表面所占据的面积,以及成膜后的临界表面张力等性能.实验结果表明,此含氟嵌段共聚物能显著降低吡咯烷酮和水的表面张力,成膜后表现出与聚四氟乙烯极为接近的低表面能特性.     

用1H NMR方法研究聚砜-聚脂类嵌段共聚物的组成和序列分布

本文测定了一系列聚矾-聚酯嵌段共聚物的高分辨核磁共振谱,研究了共聚物的组成和序列分布,山¹HNMR谱图的峰面积算出了共聚物的无规度(B)及数均序列长度(L),B值均在O相似文献   

C60与苯乙烯共聚物的制备及光电导性能的研究

通过自由基聚合的方法制备了一系列苯乙烯和Ｃ６０的共聚物。用ＴＧ＆ＤＴＡ,ＧＰＣ和ＤＳＣ等方法对共聚物进行了表征。首次在非共轭结构高分子共聚物体系上获得了光电导信号。光电导研究表明,该类共聚物具有良好光电导性能,并证明光电导来自Ｃ６０本身。     

含聚氧乙烯链段的两亲嵌段共聚物及接枝共聚物的分子设计,合成及性能

论述了由聚烯链段与聚苯乙烯或聚（甲基）丙烯酸酯链段组成的各种嵌段或接枝共聚物（包括二嵌段、两种三嵌段、星型嵌段、多嵌段、二种规整接枝共聚物等）的分子设计及合成,并总结了其两亲性质、络合碱金属离子性及微观相分离等特性。     

Controlled sulfonation of poly(arylene ether sulfone)s and poly(arylene ether ketone)s with different molecular structures for polymer electrolyte membranes

Poly(arylene ether sulfone) copolymers derived from 9,9-bis(4-hydroxyphenyl)fluorene, bisphenol S and 4,4′-difluorodiphenylsulfone and poly(arylene ether ketone) copolymers derived from 4-phenoxybiphenyl, diphenyl ether and isophthaloyl chloride were prepared as precursor polymers for sulfonation reaction in which sulfonic groups are introduced quantitatively into specified positions. Sulfonation reaction for these two series of copolymers by concentrated sulfuric acid was successfully carried out to give sulfonated polymers with controlled positions and degree of sulfonation. Thermal stability, moisture absorption and proton conductivity for these two series of copolymers were measured and the results were compared to those of perfluorosulfonic acid polymers.     

Silylation of water glass. II. Synthesis and copolymerization of carbon-functional silylated silicic acid

Carbon-functional silylates were prepared by reacting trialkoxysilanes and trimethylchlorosilane with silicic acid which had been derived from aqueous sodium silicate solution. The trialkoxysilanes used here were polymerizable silanes, i.e., vinyltriethoxysilane, (γ-methacryloyloxypropyl)trimethoxysilane, and (p-vinylphenyl)triethoxysilane. Molecular weights of these silylates containing more than one mole of the functional group ranged from 4000 to 9000. These silylates were found to serve as effective crosslinking agents for vinyl polymerization. However, soluble copolymers could be obtained under appropriate conditions, such as high dilution and low conversion in copolymerization. Glass transition temperatures (T_g) of the soluble copolymers were measured by differential scanning calorimetry to determine the effect of the silylates on the thermal properties of the copolymers. A slight variation of the T_g of these copolymers was observed when small amounts of the silylates were incorporated. It was also noticed that the water repellency of these copolymers was influenced by their composition.     

Synthesis and characterization of novel biodegradable copolyesters by transreaction of poly(ethylene terephthalate) with copoly(succinic anhydride/ethylene oxide)

Poly(ethylene terephthalate)/copoly(succinic anhydride/ethylene oxide) copolymers, (PET/PES copolymers) were synthesized by the transreaction between PET and PES and characterized with GPC, ¹H NMR, and DSC. Most of the copolymers obtained were random copolymers. The films cast of these copolymers were transparent. The thermal, mechanical properties, and biodegradability of the copolymers obtained were studied with respect to the composition and lengths of aliphatic and aromatic units in the copolymers. In the copolymers having high PET content, the melting points, due to the PET segment, were observed by DSC measurement, although the fusion heats of the copolymers were small. The enzymatic hydrolyzability by a lipase from Rhizopus arrhizus and biodegradability by activated sludge of the copolymers decreased with an increase in PET content. When the length of succinic acid unit in the copolymer was below 2, the hydrolyzability of the copolymers decreased considerably. The tensile strengths of the cast films prepared from the copolymers synthesized by the transreaction increased with an increase in PET content, whereas, the elongations at break decreased. Their tensile strengths were half, and the elongations were double compared to those of PET homopolymer film. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4478–4489, 2000     

Melting behavior of ethylene copolymers and branched polyethylenes

Prior research on the melting behavior of ethylene copolymers and branched polyethylenes could not be effectively evaluated since there were large differences in the levels of comonomer contents. The present research was undertaken to determine additional data so that an overall evaluation could be made. A consideration of the experimental data of the present work and earlier research data showed that methyl side groups caused less diffuse melting and less melting point depression than either ethyl groups or polyethylene branches. In addition, it was found that the Flory equation can be used to describe the relation of melting point depression to foreign group concentration for propylene copolymers. The equation did not hold for 1-butene-ethylene copolymers or branched polyethylenes. For these materials the Wunderlich modification of the Flory equation applied. Activity values for both 1-butene-ethylene copolymers and branched polyethylenes gave a common correlation with foreign groups. Enthalpy and entropy fusion data for ethylene copolymers and branched polyethylenes were also determined. It was also shown that good agreement was found between crystallinities for these materials determined independently by differential thermal analysis and x-ray analysis.     

Synthesis and characterization of all‐conjugated copolymers of 3‐hexyl‐thiophene and EDOT by grignard metathesis polymerization

Random regioregular copolymers of 3‐hexylthiophene and 3,4‐ethylenedioxythiophene were synthesized by grignard metathesis polymerization. Soluble copolymers were obtained with a high degree of regioregularity and with a monomer ratio close to the feed ratio. A comparison between the optical properties and the thin film morphologies of these copolymers and poly(3‐hexylthiophene) is also presented. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Self-organization behavior of methacrylate-based amphiphilic di- and triblock copolymers

Amphiphilic di- and triblock copolymers having different hydrophilic-to-hydrophobic block length ratio were synthesized using ATRP. The self-assembly behavior of these AB and ABA block copolymers consisting of poly(n-butyl methacrylate) (B) and poly(2,2-(dimethylaminoethyl methacrylate) (A) was investigated using a combination of dynamic light scattering, negative-stain transmission electron microscopy, cryoelectron microscopy, and atomic force microscopy. Two populations of self-organized structures in aqueous solution, micelles and compound micelles, were detected for diblock copolymers. Triblock copolymers assembled into vesicular structures of uniform sizes. Furthermore it was found that these vesicles tended to compensate the high curvature by additional organization of the polymer chains outside of the membrane. The chain hydrophilicity of the polymers appeared to have a critical impact on the self-assembly response toward temperature change. The self-reorganization of the polymers at different temperatures is discussed.     

聚砜-尼龙6嵌段共聚体的溶液性质及其与聚砜、尼龙6均聚物的相容性的研究

<正> 我们曾在前二篇文章中指出非晶型双酚A聚砜(以下用B表示)与结晶形尼龙6(以下用N表示)经共混得到的共混物很脆,而聚砜-尼龙6嵌段共聚物(以下用B-N和N-B-N表示)却具有较B或N更优的耐溶剂性和耐水性,但是嵌段共聚物中B组分含量不能超过25％,这样就限制了材料的使用范围,然而由于B-N(或N-B-N)在同一分     

侧基带有L-苯丙氨酸的手性两亲嵌段共聚物的合成及其自组装行为

N3-苯丙氨酸与嵌段共聚物聚乙二醇-b-聚炔丙基缩水甘油(MPEO-b-PGPE)发生"click"反应,合成了具有光学活性的两亲嵌段共聚物聚乙二醇-B-聚L-苯丙氨酸三唑基缩水甘油(MPEO-b-PGTP),用1H-NMR和元素分析对其结构和组成进行表征.并对其自组装行为进行研究,滴体积法测定MPEO-b-PGTP溶...