氨基树脂交联型聚合物的合成及其取向松驰

用双羟基偶氮苯化合物与对苯二甲酰氯缩聚反应合成了端羟基偶氮苯低聚物，将其与丁醇醚化氨基树脂进行电场极化交联反尖合成交联型非线性光学聚合物。利用红外光谱和紫外可见吸收光谱分别对交联反应、电场极化取向稳定性进行了研究。     

带液晶侧基的交联二阶非线性光学聚合物的合成和极化

对硝基氧化偶氮苯缩水甘油醚（４）经酸碱开环反应合成得对硝基氧化偶氮苯甘油单醚（５）．ＤＳＣ和偏光显微镜结果表明这两种低分子化合物都能形成液晶相。将（５）与六亚甲基二异氰酸酯的缩二脲进行电场极化交联反应，合成了交联型非线性光学聚合物，用交温ＦＴＩＲ和ＤＳＣ研究了交联反应过程。利用紫外可见吸收光谱研究了膜极化交联前后的取向及取向稳定性。     

高Tg交联型二阶非线性光学聚合物的合成

合成了双羟基双氨基偶氮苯化合物，将其分别与六亚甲基二异氰酸酯的缩二脲和２，４－甲苯二异氰酸酯进行交联反应合成了两种交联型二阶非线性光学聚合物，利用ＦＴＩＲ光谱和ＤＳＣ对交反应过程和交联聚合物的玻璃化转变温度进行研究。采用ＵＶ－Ｖｉｓ吸收光谱对极化交联反应前后膜的取向及取向稳定性进行了研究。     

交联型非线性光学聚合物的合成

利用六亚甲基二异氰酸酯的缩二脲与对硝基偶氮苯甘油单醚的电场极化交联反应合成交联型聚合物非线性光学材料．采用变温红外光谱、ＤＳＣ、紫外可见吸收光谱研究交联反应时间对非线性生色基团的取向及松弛的影响．     

氧化偶氮液晶二阶非线性光学聚合物的研究

将４－［对硝基苯基氧化偶氮苯基］甘油单醚与六亚四基二异氰酸酯的缩二脲进行电场极化交联反应，合成交联型非线性光学聚合物，并用ＦＴ－ＩＲ光谱和ＤＳＣ对交联反应过程进行了详细研究。利用紫外可见吸收光谱对膜极化前后的取向以及在室温和温下取向膜的稳定性进行了研究，并对极化膜的非线性光学系数ｄ３３了推算。     

多异氰酸酯交联型二阶非线性光学聚合物中的极化与松弛

通过４，４＇－硝基偶氮苯甘油单醚与六亚甲基二异氰酸酯的缩二脲在电场下极化交联反应合成交联型二阶非线性光学聚合物。利用二次谐波和紫外可见吸收光谱对该聚合物的取向及松弛进行了研究。测试了二阶非线性极化率χ＾（２）、二阶非线性光学系数ｄ３３和电光系数λ３３，表明上述极化交联聚合物的ｄ３３在１０＾－８￣１０＾－７ｅｓｕ，在测试时间范围内基本不随时间而衰减。     

侧基含羟基的主链偶氮苯液晶共聚酯的合成及其光响应行为

以4,4’-双(6-羟基己氧基)联苯(BHHBP)、4,4’-双(6-羟基己氧基)偶氮苯(BHHAB)为液晶基元,利用苹果酸二乙酯(DM)和苯基丁二酸(PSA)采用无规共聚,合成了侧基含羟基的偶氮苯液晶共聚酯(Az-LCP).先在液晶态下拉伸取向,然后用六亚甲基二异氰酸酯(HDI)交联制备单畴取向偶氮苯液晶交联网络.通过核磁共振氢谱(1H-NMR)、凝胶渗透色谱(GPC)测试,对合成的Az-LCP进行结构表征,通过示差扫描量热分析(DSC)、X射线衍射(XRD)、偏光光学显微镜(POM)等对其液晶相变行为进行表征,研究了偶氮苯含量、交联密度、薄膜厚度对其光致弯曲行为的影响.结果表明,偶氮苯含量10%,交联12 h的Az-LCP1具有最佳的光致弯曲回复行为.     

含氧化偶氮苯介晶基元共聚醚的合成与液晶行为

以1,6-二溴己烷(A)和1,10-二溴癸烷(B)为共缩聚单体,按不同摩尔配比与4,4'-二羟基氧化偶氮苯经相转移催化共聚醚化反应,合成了一系列主链上含有氧化偶氮苯介晶基元的共聚醚,它们均有好的液晶性,其取向膜观察到条带织构,当A/B的摩尔比为1时液晶态范围最宽。     

含偶氮苯或联苯侧基聚醚螯合树脂的合成及其络合性能研究

通过聚环氧氯丙烷分别与4—氨基偶氮苯、4—氨基—2′,3—二甲基偶氮苯、4—氨基—4′—氯—联苯和4—羟基偶氮苯反应,合成了四种以聚醚为主链的偶氮和芳胺型螯合树脂,并研究了它们对Au(Ⅲ)、Pd(Ⅱ)、Pt(Ⅳ)、Hg(Ⅱ)、Cu(Ⅱ)和Pb(Ⅱ)的吸附性能。     

结肠定位给药系统载体偶氮聚合物合成-对甲基丙烯酰胺偶氮苯的合成与表征

为了设计与合成新的结肠靶向给药系统载体-三元偶氮共聚物，提出合成一种新的偶氮功能单体—对甲基丙烯酰胺偶氮苯[Bis(methacryloylamino)-azobengene，BMAAB]作为偶氮聚合物交联剂。BMAAB合成方法：先将对硝基苯胺氧化偶联，再还原成对胺基偶氮苯(DAXB)，最后再与甲基丙烯酰氯反应。用紫外、红外、核磁共振与差热分析对产物进行了表征。     

Synthesis and properties of phthalonitrile-terminated oligomeric poly(ether imide)s containing phthalazinone moiety

Three novel series of soluble and curable phthalonitrile-terminated oligomeric poly(ether imide)s containing phthalazinone moiety were synthesized from an excess amount of three dianhydrides and phthalazinone-based diamine, followed by reacting with 4-(3-aminophenoxy)phthalonitrile (APPh) in a two-step, one-pot reaction, respectively. The phthalonitrile oligomers containing phthalazinone moiety were cured in the presence of 4,4′-diaminodiphenylsulfone (DDS). The oligomers and the crosslinked polymers were characterized by DSC, FT-IR and elemental analysis. These phthalonitrile oligomers containing phthalazinone groups were found to be soluble in some aprotic solvents, such as chloroform, pyridine, m-cresol and N-methyl-2-pyrrolidone (NMP). The crosslinked polymers were insoluble in all solvents. The thermal properties of the oligomers and the crosslinked polymers were evaluated using DSC and TGA analysis. The phthalonitrile oligomers showed high glass transition temperatures (T_gs) in the range of 214-256 °C and high decomposition temperatures with 10% weight loss (T_d10%) ranging from 523 to 553 °C. The crosslinked polymers showed excellent thermal stability with the 10% weight loss temperatures ranging from 543 to 595 °C, but did not exhibit a glass transition temperature upon heating to 350 °C.     

Synthesis and study of polymerization and copolymerization of some oligounsaturated esters—V

A number of oligoacetylenic acrylates have been synthesized and characterized. The i.r. as well as the physical and chemical properties show the probable formation of oligomers possessing a proposed structure. The oligomers undergo further reaction in the presence of peroxide initiators to give crosslinked products. The i.r. spectra of the crosslinked products show that the oligomers undergo addition polymerization on the terminal double bonds. The triple bond in these oligomers is relatively unreactive under the conditions of polymerization, while that in the glycolic residue is reactive to a certain extent, as indicated by the higher per cent conversion of the oligomers having such unsaturated glycolic residue.Copolymerization of various oligoacetylenic acrylates, methacrylates and esters with terminal allylic group with styrene give crosslinked products. The polymers and copolymers are pale yellow in colour, glassy, insoluble in organic solvents and infusible; the copolymers were more rigid than the homopolymers. The volume shrinkage of various oligomers during polymerization lies between 5 and 13 per cent.     

Thermally reversible linking of halide-containing polymers by potassium dicyclopentadienedicarboxylate

A novel crosslinker for thermally reversible covalent (TRC) linking of halide-containing polymers is suggested. Chlorine-containing polymers such as chloromethylstyrene copolymers, chlorinated polypropylene, polyvinylchloride, chlorinated polyisoprene, and polyepichlorohydrin were crosslinked with potassium dicyclopentadienedicarboxylate (KDCPDCA). The crosslinker was prepared by reacting potassium ethoxide with dicyclopentadienedicarboxylic acid. Because of the low solubility of KDCPDCA in organic solvents, a phase transfer catalyst, benzyltrimethyl-ammonium bromide, was employed for the crosslinking reaction. The crosslinking reaction occurred at a higher rate in a polar solvent, such as dimethylformamide, than in a nonpolar one, such as toluene, and was affected by the nature of the chlorine-containing polymer. Some of the polymers crosslinked even at room temperature. The chain-extending reaction between KDCPDCA and a α,ω-dihalide compound such as α,α′-dichloro-p-xylene, 1,4-dichlorobutane, or 1,4-dibromobutane also was carried out to obtain linear oligomers. The IR spectra indicated that the crosslinking and chain-extending reactions were based on the esterification between the halide carbon bonds of the polymer and the COOK groups of KDCPDCA. The flowability at 195 °C and solubility on heating in a dichlorobenzen-maleic compound mixture of the crosslinked polymers indicated that the TRC crosslinking occurred via the reversible Diels–Alder cyclopentadiene/dicyclopentadiene conversion as long as the polymer was thermally stable and did not contain olefinic CC bonds. The TRC linking also was confirmed by the rapid decrease of the specific viscosity of the obtained linear oligomers on heating. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4390–4401, 1999     

Investigation of the Structure and Properties of Crosslinked Polymers Based on Oligocarbonate Methacrylates in Film Formation

The effect of structure and flexibility of an oligomeric block of oligocarbonate methacrylates (OCM) as well as of various modifiers on the coating formation, the structure, and properties of crosslinked polymers formed under conditions of adhesive interaction has been studied. Reactivity and conversion of OCM during polymerization increase in coatings formed from oligomers with short and rigid blocks, capable of forming on the substrate a network from the ordered anisodiametric structural elements with high adhesive properties, as distinct from the globular structures appearing in the formation of the network from the oligomers with more flexible blocks. The tendencies observed have been explained with the aid of a mechanism of network formation relating the morphology of the resultant crosslinked polymers to the flexibility (conformation) of the chains of the branched polymer obtained in the initial stage of polymerization and representing a matrix of the corresponding crosslinked structures. The mode of action of modifiers is markedly dependent on the nature and flexibility of the oligomeric block.     

Multifunctional small molecule for controlled assembly of oligomeric nanoparticles and crosslinked polymers

One multifunctional small molecule can undergo a natural condensation reaction under the control of reducing agent to generate amphiphilic oligomers which quickly self-assemble supramolecular nanoparticles or form crosslinked, reversibly degradable polymers.     

Some rheological properties of highly crosslinked polysiloxanes

Seven crosslinked polydimethylsiloxanes were prepared from carboxyl-terminated siloxane oligomers of different average lengths and a trifunctional imine. The 10-sec torsion modulus was measured as a function of temperature, and compression-deflection data were obtained on swollen specimens. Polymer-solvent interaction parameters were calculated from equilibrium swelling ratios and modulus data. The plots of modulus versus temperature show two distinct transitions for all the crosslinked polymers. The low-temperature transition corresponds to the siloxane chains, whereas the high-temperature transition should be attributed to the portion of the network chain derived from the crosslinking agent and the organic part of the oligosiloxane. On shortening the siloxane blocks, both transitions shift to successively higher temperatures and higher modulus levels. However, the siloxane transition temperature shows only a limited rise even when the average block length becomes quite small. The low siloxane polymers seem to exhibit two swelling maxima, each corresponding to one of the constituents. The studied materials from nonrandom copolymeric structures typical of block polymers. Such microphase systems can probably be expected in crosslinked polymers whenever the crosslinking agent participates significantly in the network chains and its compatibility with the flexible chains species is poor.     

Photocrosslinkable polyesters and poly(ester anhydride)s for biomedical applications

Crosslinking is a feasible way to prepare biodegradable polymers with potential in biomedical applications such as controlled release of active agents and tissue engineering. A synthesis route in which functional telechelic aliphatic polyester oligomers are used as precursors for the preparation of crosslinked polyesters and poly(ester anhydride)s is described. Mechanical properties, degradation characteristics and rate, and bioactivity can be modified widely by controlling the chemical composition and architecture of the crosslinkable oligomers. In tissue engineering, photocrosslinking allows to use crosslinkable oligomers in advanced manufacturing techniques like micromolding in capillaries, stereolithography and two-photon polymerization.     

Curing of epoxy oligomers by the eutectic mixture of aromatic amines

Kinetics of curing of structurally different epoxy oligomers (ED-20 and PDI-3AK resins) in a mixture with other low-molecular-weight epoxy oligomers and plasticizers by the eutectic mixture of aromatic amines UP-0638/1 is studied by the DSC method. The activation energy and the heats of curing reactions are determined. It is established that crosslinked epoxy polymers cured at moderate temperatures (40–80°C) are strong moisture-resistant compositions with different mechanical characteristics. Plasicized elastomers based on PDI-3AK resin with glass transition temperatures of ?78 and ?95°C are freeze-and heat-resistant materials.     

Degradable polyesters through chain linking for packaging and biomedical applications

The major route to convert lactic acid to high-molecular-weight polymers is ring-opening polymerization of lactide. We have investigated alternative synthesis routes based on oligomerization and chain linking to produce high-molecular-weight thermoplastic degradable polymers cost-effectively. Chain linking also offers new possibilities to prepare degradable polyesters for biomedical applications by extending the range of polymer properties achievable. In this paper, we briefly review different chain linking techniques used in our laboratory. Typically, lactic acid prepolymers with molecular weights of around 3,000-15,000 g x mol(-1) have been prepared by direct polycondensation. Hydroxyl terminated oligomers have been chain linked by using diisocyanate coupling agents, preferably 1,4-butane diisocyanate, forming poly(ester-urethanes). Poly(ester-amides) have been prepared by using 2,2'-bis(2-oxazoline) as coupling agent for carboxylic acid telechelic oligomers. Chain linking by end functionalization has been used in the preparation of poly(ester-anhydrides). In addition, a variety of crosslinked degradable polymers and copolymers have been synthesized through different crosslinking routes, by using methacrylic, itaconic or maleic double bonds or triethoxysilane moieties. A biodegradation test and ecotoxicological evaluation of the degradation products were carried out in addition to hydrolysis tests. Lactic acid based chain linked polymers were biodegradable and the degradation products were harmless. In hydrolysis tests, enzymatic degradation was pronounced in the chain linked poly(epsilon-caprolactone).     

Studies on the thermotropic liquid crystalline polymer. XII. Synthesis and properties of crosslinkable thermotropic liquid crystalline homo- and copoly(ether-ester)s

A series of crosslinkable thermotropic liquid crystalline poly(ether-ester)s and copoly(ether-ester)s was prepared. All of the polymers were crosslinked by thermal treatment or photo-irradiation upon heating. The thermal stability and thermal crosslinking reaction of these polymers were investigated. These polymers also could be crosslinked by copolymerization with vinyl monomers, such as styrene or methyl methacrylate. The crosslinked polymers exhibited thermotropic liquid crystalline behavior after softening by heating. The phase behavior of linear polymers and crosslinked polymers was studied by differential scanning calorimetry (DSC) and an optical polarizing microscope equipped with a heating stage. © 1995 John Wiley & Sons, Inc.