超临界二氧化碳中CTFE和VAc共聚物的合成及性能

以超临界二氧化碳流体为反应介质,制备了醋酸乙烯酯(VAc)和三氟氯乙烯(CTFE)的共聚物。研究了单体配比、引发剂用量、压力及温度对反应的影响,并对产物的结构及膜性能等进行了表征。实验结果表明,通过控制反应条件可以得到不同分子量、不同氟含量的共聚物,且共聚物中氟含量的不同是聚合物膜对溶剂接触角变化的原因。     

N-PMI/丁苯胶乳乳液共聚物的合成及热性能研究

采用乳液共聚合的方法,以N-苯基马来酰亚胺(N-PMI)为耐热改性单体与丙烯腈、苯乙烯、丁苯胶乳(SB)乳液共聚合合成了耐热ABS树脂.用DSC、TBA及TGA热分析方法对不同单体配比共聚物的热性能进行了表征,用GPC测定了共聚物的分子量和分子量分布.结果表明,N-PMI的加入能有效提高ABS的耐热性,玻璃化温度和热分解温度均随N-PMI含量的增加而升高.     

双亲性嵌段共聚物PS-b-PNVA的RAFT制备及其自组装行为研究

以偶氮二异丁氰(AIBN)为引发剂,二硫化二异丙基黄原酸酯(DIP)为RAFT试剂,引发活性较大的单体苯乙烯(S)和活性较小的单体N-乙烯基乙酰胺(NVA)聚合,成功合成了结构明确、分子量分布较窄(Mw/Mn=1.39)的PSb-PNVA嵌段共聚物并对嵌段共聚物的自组装行为进行了研究。利用凝胶渗透色谱、傅里叶变换红外光谱、核磁共振、纳米粒度仪和透射电镜对嵌段共聚物的分子量、结构及其在水溶液中的聚集行为进行了研究。详细考察了聚合反应温度、RAFT试剂用量、聚苯乙烯分子量等条件对嵌段共聚物的分子量及分布的影响以及嵌段共聚物结构、浓度和水含量等因素对嵌段共聚物形成的胶束的粒径的影响。     

甲基丙烯酸甲酯与丙烯酸丁酯规整接枝共聚物的合成及性能研究

采用聚丙烯酸丁酯大分子单体和甲基丙烯酸甲酯小分子单体共聚 ,合成了以甲基丙酸甲酯为主链、丙烯酸丁酯为支链的规整接枝共聚物。用红外光谱表征结构 ,研究了大单体的投料量、引发剂的用量及共聚反应温度对接枝效率的影响。并且研究了接枝共聚物的力学性能影响因素 ,当聚丙烯酸丁酯大单体的分子量大于 50 0 0 ,投料重量百分比在 6 0 %左右 ,得到性能良好的热塑性弹性体     

PMMA-g-PEG的制备及其相转变性能研究

使甲基丙烯酸单封端聚乙二醇大分子单体(MA-PEG)与甲基丙烯酸甲酯(MMA)在N,N-二甲基甲酰胺(DMF)中进行自由基接枝共聚反应,得到了以PEG为支链,聚甲基丙烯酸甲酯为主链(PMMA-g-PEG)的接枝共聚物.用核磁共振(1H-NMR),傅立叶红外光谱(FTIR)和凝胶渗透色谱(GPC)对PMMA-g-PFG的结构与相对分子量进行了表征.结果表明,所合成的共聚物结构明确,在MA-PEG大分子单体与MMA的不同配比条件下,得到的PMMA-g-PEG的分子量和分子量分布基本相同.并通过差示扫描量热仪(DSC)研究了接枝共聚物的热力学性质,结果表明,PMMA-g-PEG具有明显的相转变,其相变焓、相变温度与PEG的含量有关,并且随其含量的增加而增大.     

CuX/bpy催化体系中聚氧乙烯大单体与甲基丙烯酸甲酯接枝共聚物的合成与表征

以正丁基溴为引发剂，卤化亚铜／联吡啶(bpy)为催化剂，研究了甲基丙烯酸甲酯（MMA）与末端为丙烯酰胺基的聚氧化乙烯（PEO）大单体的原子转移自由基聚合（AWTRP）反应，得到的实测分子量与理论分子量相近，分子量分布较窄，有预期结构的接枝共聚物，用IR，^1H-NMR,VPO,GPC,DSC等进行表征，并对单体总浓度，投料比，引发剂及反应时间对共聚物的组成和分子量的影响进行了讨论。     

聚6-氨基己酸-β-丙氨酸的合成及降解行为研究

采用熔融缩聚法制备了一种新型可降解的6-氨基己酸(6N)和β-丙氨酸(βA)的二元共聚物(PAA),并研究了该共聚物的性能。采用红外光谱分析(FT-IR)、X射线衍射分析(XRD)、差示扫描量热分析(DSC)、热重分析(TGA)等手段对其结构进行了表征,结果表明,所合成的材料是2种单体的聚酰胺共聚物;随β-丙氨酸含量的增加,共聚物的结晶度、熔融温度呈先减小后增大的趋势,而分解温度呈依次减小的趋势,当共聚物中2种单体摩尔比为1∶1时,其为无定形共聚物。共聚物在去离子水中的降解实验结果表明,材料具有良好的降解性能;不同单体比例合成的共聚物中,共聚物的降解速率与共聚物的结晶度成反比,当聚合物中2种单体摩尔比为1∶1时,聚合物的降解速度最快,2周后几乎完全降解;整个降解过程中,降解液的pH值都维持在相对稳定的水平。在环保方面,该材料可望有良好的应用前景。     

水相沉淀聚合法制备不同单体配比的AN/MA共聚物研究

以过硫酸铵(APS)为引发剂,采用水相沉淀聚合工艺制备了不同单体的丙烯腈/丙烯酸甲酯(AN/MA)共聚物。研究了单体配比对AN/MA共聚合反应和共聚物化学结构的影响。结果表明:该工艺制得的PAN聚合物的具有较高的粘均分子量。红外谱图上存在C=O基团的伸缩振动峰及其吸收峰强度随共聚单体用量增加而增强,表明AN与MA发生了共聚合反应。     

含糖密接枝共聚物的合成

采用马来酰亚胺类双键的可逆Diels-Alder反应和糖单体6-O-甲基丙烯酰基-1,2;3,4-双-O-亚异丙基--αD-吡喃半乳糖苷(MAIPGal)在室温下的原子转移自由基聚合(ATRP)合成了端基为马来酰亚胺的大分子糖单体,然后和苯乙烯共聚得到含糖密接枝共聚物。用核磁共振(1H-NMR)和凝胶渗透色谱(GPC)表征了大分子单体和接枝共聚物的结构和分子量,结果表明,接枝共聚物侧链长度均一,主链结构规整,分布窄。脱保护后得到两亲性共聚物。用透射电镜(TEM)考察了两亲性接枝共聚物在水溶液中的聚集行为,可以观察到囊泡、胶团等结构。     

水相沉淀法制备丙烯腈/丙烯酰胺共聚物的工艺研究

以丙烯酰胺为共聚单体,选择过硫酸铵为引发剂,采用水相沉淀法制备了丙烯腈/丙烯酰胺共聚物。研究了引发剂浓度、单体配比、聚合温度及链转移剂和终止剂的选用对共聚物转化率和分子量的影响。结果表明,反应温度宜控制在65℃,随着引发剂和共聚单体的增加,共聚物的转化率提高而分子量降低。引入链转移剂并未改变分子链结构,从热性能上看乙醇胺效果较好。而终止剂宜选用N,N-二乙基羟胺。     

新型喹啉衍生物类单体与苯乙烯的原子转移自由基共聚及荧光性能研究

合成了一种新型的喹啉衍生物类单体2,7,7-三甲基-3-乙氧羰基-4-(4-丙烯酰胺苯基)-5-氧代-1,4,5,6,7,8-六氢喹啉(TEOHQ),并通过原子转移自由基聚合(ATRP)的方法制备了TEOHQ与苯乙烯的共聚物。以元素分析,GPC,1H-NMR及荧光发射光谱表征了共聚物。数均分子量(M-n)随转化率的线性增加及相对较窄的分子量分布(M-w/M-n)证明了聚合的可控性。同时,利用Mayo-Lewis公式测定了两种单体的竞聚率。最后,从共聚物荧光发射光谱图中显示出共聚物的最大发射峰位于436 nm处,相对于425 nm处单体TEOHQ的最大发射峰发生了11nm的红移。     

Synthesis and the third-order non-linear optical properties of new azobenzene-containing side-chain polymers

A new series of aromatic azobenzol compounds containing vinyl have been designed as monomers. The azobenzene-containing side-chain polymers containing azo NLO chromophore in each side chain have been synthesized via free radical polymerization. FT-IR, elemental analysis and ¹H NMR were performed to characterize the azo monomers. The molecular weight of the polymers and their distribution were determined by gel permeation chromatography (GPC). The third-order NLO coefficient of azo monomers and their polymers were measured by degenerated four wave mixing (DFWM) technique. As a result, the enhancement of the molecular conjugation and the increase of the NLO chromophore concentration in the molecular chain contribute much to heightening the third-order NLO effect. The electronic effect of substituent on the azobenzol group and the push–pull electronic structure contributes much to enhancing the NLO property.     

Synthesis and the third-order non-linear optical properties of new azobenzene-containing side-chain polymers

A new series of aromatic azobenzol compounds containing vinyl have been designed as monomers. The azobenzene-containing side-chain polymers containing azo NLO chromophore in each side chain have been synthesized via free radical polymerization. FT-IR, elemental analysis and ¹H NMR were performed to characterize the azo monomers. The molecular weight of the polymers and their distribution were determined by gel permeation chromatography (GPC). The third-order NLO coefficient of azo monomers and their polymers were measured by degenerated four wave mixing (DFWM) technique. As a result, the enhancement of the molecular conjugation and the increase of the NLO chromophore concentration in the molecular chain contribute much to heightening the third-order NLO effect. The electronic effect of substituent on the azobenzol group and the push–pull electronic structure contributes much to enhancing the NLO property.     

含聚环氧乙烷的两性多嵌段共聚物的某些性能

研究了(苯乙烯-丁二烯-环氧乙烷)两性多嵌段共聚物的吸水性能、乳化性能及结晶性能。结果表明,共聚物具有良好的吸水性能和乳化性能,共聚物中聚环氧乙烷含量和预聚体聚乙二醇的分子量是影响上述性能的主要因素。共聚物中聚环氧乙烷含量影响共聚物的结晶度和结晶形态,不同的浇铸溶剂对嵌段共聚物结晶形态也有影响。     

聚氨酯阻尼材料的结构设计及其动态力学性能的研究

据聚合物阻尼性能定量化理论，设计合成了软段结构、分子量不同以厦含支链的聚氨酯．动态力学性能测试表明。含聚环氧丙烷二醇（PPG，Mn=2000）、聚己二酸二乙二醇（PDEA，Mn=2000）、聚己二酸乙二醇（PEAG，Mn=2000）软段的试样的温域宽和内耗峰高．当软段分子量增加时，材料的损耗因子增加．组份相同时，含支链比不舍支链的聚氨酯试样的内耗峰高，阻尼值大．     

Characterisation of Bionate polycarbonate polyurethanes for orthopaedic applications

Two polycarbonate polyurethanes, Bionate 75D and Bionate 80A, have been characterized for application in biomimetic joint replacement systems. Procedures involved measurement of the effects of compounding and moulding on molecular weight, melt rheometry, and mechanical testing using conditioned and aged specimens. The effects of compounding with hydroxyapatite and carbon fibres were also evaluated. With Bionate 75D moulding reduces the molecular weight by 30%. Passing the material through a twin screw extruder without filler has similar molecular weight reduction effects to injection moulding. Inclusion of carbon fibre has little additional effect on molecular weight, although moulding of the fibre filled compound causes some further degradation, and Mw is almost halved compared with the original value. Inclusion of hydroxyapatite reduces Mw in a moulded component to less than a quarter of the original value and some form of chemical interaction between the polymer and filler is presumed. The apparent melt viscosity of the Bionate 75D was reduced by the addition of both carbon fibres and hydroxyapatite and this is thought to arise from reduction in molecular weight during the compounding process and the development of shear planes at the polymer-filler interface. The polymer glass transition temperatures are shifted to slightly higher values by the inclusion of filler. The tensile test results show the reinforcing effect of the carbon fibres, but poor wetting and pull out of the fibres was evident. Water absorption results suggest that the materials stabilise after 2 weeks, but the tensile results indicate that property change occurred between 1 month and 5 months of exposure. However the shape of the stress-strain curves is not altered, but with extended water exposure is translated to lower stress levels.     

聚砜-聚对苯二甲酸乙二醇酯嵌段共聚物对聚砜/半芳族聚酯液晶共混体系的增容改性作用

合成了具有不同分子量的PSF－PET共聚物。考察了这种共聚物对于聚砜／热致液晶聚合物（PSF／TLCP）共混物的增容改性效果。这种增容剂的增容改性效果与其分子量的大小有关,分子量较大共聚物的增容效果较好。与未增容体系相比,只加入少量分子量较高的PSF－PET共聚物,原位复合体系的多项力学性能得到明显提高,液晶聚合物分散相分散更均匀,且仍然以微纤状分散在基体中。     

疏水性增透聚酯薄膜的制备及应用

以聚苯乙烯为大分子引发剂,丙烯酸聚硅氧烷酯为单体,通过原子转移自由基聚合制备苯乙烯-丙烯酸聚二甲基硅氧烷酯共聚物。将所得聚合物旋涂于聚对苯二甲酸乙二醇酯(PET)薄膜表面,研究共聚物中不同硅氧烷含量对聚酯薄膜性能的影响。通过核磁共振和红外光谱表征了丙烯酸聚硅氧烷酯单体及与苯乙烯共聚产物的结构,结果表明实验成功制备出了苯乙烯共聚物;凝胶渗透色谱结果表明聚合物的相对分子质量与设计相对分子质量相接近,并且相对分子质量分布系数均小于1.4,说明反应具有一定可控性;紫外-可见光分光光度计结果表明聚合物的折射率随着嵌段聚合物中硅氧烷含量的降低而增加;通过场发射扫描电镜(FE-SEM)对改性前后的聚酯薄膜进行观察,结果显示聚酯薄膜表面形成了蜂窝状多孔结构,从而有效改善了薄膜的透光性。总体研究结果表明,随着共聚物中硅氧烷含量的增加,聚酯薄膜的水接触角和透光率均呈先增后减的趋势。当共聚物中硅氧烷含量为19.6%时,PS-PDMS嵌段共聚物折射率为1.38,涂覆在PET表面后薄膜透光率达到92.6%,水接触角为120°。     

Fluorescent molecular thermometers based on polymers showing temperature-induced phase transitions and labeled with polarity-responsive benzofurazans

Poly(N-isopropylacrylamide) in aqueous solution undergoes a phase transition at approximately 32 degrees C. The fluorescence properties of benzofurazans are affected by solvent polarity. We combine these two characteristics for the first time to develop sensitive fluorescent molecular thermometers. Five fluorescent monomers having a benzofurazan skeleton were synthesized, and the copolymers of N-isopropylacrylamide (NIPAM) and a small quantity of the fluorescent monomer were obtained to investigate their fluorescence properties. With increase in temperature, the copolymers in water showed the temperature-induced phase transition at approximately 32 degrees C and the fluorescence intensities of the copolymers concurrently increased. Especially, for the copolymer of 4-N-(2-acryloyloxyethyl)-N-methylamino-7-N,N-dimethylaminosulfonyl-2,1,3-benzoxadiazole and NIPAM, the fluorescence intensity at 37 degrees C was 13.3-fold that seen at 29 degrees C. The sensitive range of temperature of these fluorescent molecular thermometers is changed by the replacement of the NIPAM units by N-isopropylmethacrylamide or N-n-propylacrylamide units in the copolymers. The basis of these fluorescent molecular thermometers is the decrease in the microenvironmental polarities near the main chains of the copolymers with increasing temperature, as confirmed from the maximum emission wavelengths of the benzofurazan units in the copolymers. The responses from the copolymers to the change in temperature are reversible and exactly repeatable during at least 10 cycles of heating and cooling.     

Influence of the molecular parameters of anionic acrylamide copolymers on the value of the Thoms effect in direct oil emulsions

The influence of molecular parameters (molecular weight and polydispersity in molecular weight) on the value of the reduced Thoms effect in 10% direct oil emulsions has been analyzed with the example of the specimens of anionic acrylamide copolymer of different molecular weight, which were obtained by the ultrasonic-destruction method. The prospects of anionic acrylamide copolymers for use as admixtures reducing the drag of turbulent oil-emulsion flows have been noted for the complex heterophase system studied. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 3, pp. 155–163, May–June, 2007.