含活性硅氧烷型大分子改性剂BA-MMA-VTES的合成与表征

针对弱极性天然/丁苯橡胶复合体系,从分子设计的角度出发,选择乙烯基三乙氧基硅氧烷(VTES)、丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)为单体,通过自由基溶液聚合并优化了反应条件:在85℃和115℃分别加入两种不同量的引发剂BPO和DCP,均保温反应2h,合成了三元共聚物BA-MMA-VTES大分子表面改性剂,用于纳米碳化硅、氮化硅陶瓷粉体的表面改性。采用FTIR、NMR、GPC、DSC、TGA等对所合成的三元共聚物的结构、性质和数均相对分子质量进行了分析和表征。通过FTIR、NMR测试结果,证实了BA-MMA-VTES三元共聚物的结构;通过GPC测试,证明BA-MMA-VTES三元共聚物的数均相对分子质量控制在3000～10000;DSC显示合成的大分子只有一个Tg,在3.3℃左右,表明它是无规共聚物,柔性适中;TGA显示三元共聚物主要热分解区间在280～500℃,热稳定性良好。     

AM/AA/DMDAAC三元共聚物的合成及性能

采用氧化-还原引发体系合成了丙烯酰胺(AM)/丙烯酸(AA)/二甲基二烯丙基氯化铵(DMDAAC)三元共聚物,并对此三元共聚物的泥浆性能进行了初步评价。结果表明,AM/AA/DMDAAC三元共聚物具有较强的降滤失、抑制页岩水化膨胀能力。     

Synthesis and properties of high oil‐absorbent 4‐tert‐butylstyrene‐EPDM‐divinylbenzene graft terpolymer

The graft crosslinking polymerization of 4‐tert‐butylstyrene (tBS) and divinylbenzene (DVB) onto ethylene–propylene–diene (EPDM) was carried out in toluene by using benzoyl peroxide (BPO) as an initiator. The synthesized graft terpolymer, tBS‐EPDM‐DVB (PBED), was extracted with tetrahydrofuran (THF) into gel (called as PBED I) and sol, and then they were identified by infrared (IR) spectroscopy. The effects of solvent amount, molar ratio of DVB to tBS, EPDM content, initiator concentration, reaction temperature, and reaction time on the graft crosslinking polymerization were examined. Among them, solvent amount and molar ratio of DVB to tBS were the important factors for this reaction system. Maximum oil absorbency of PBED I was 84.0 g/g but its oil‐absorption kinetic rate was very low. Sol PBED can be reused as oil absorbent (named as PBED II) through photocrosslinking by ultraviolet light irradiation. Although the oil absorbencies of PBED II were lower than those of PBED I in most cases, their oil absorption kinetic rates were higher than oil absorbencies of PBED I. The highest value of oil absorbency of PBED II was 56.0 g/g. The thermal stability of PBED I was studied by TGA. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2119–2129, 2002     

耐化学腐蚀装饰胶的合成和性能表征

采用醋酸乙烯和丙烯酸酯三元共聚合的方法,合成出了性能优良的建筑装饰胶粘剂。用以粘合胶合板单层板,固化后浸于水、10% NaOH、HCl、尿素等水溶液以及饱和的Ca(OH)_2溶液中,皆为60天不开裂。     

Gas and water vapour transport in a polyketone terpolymer

Gas and water vapour transport properties of a polyketone terpolymer (0.93/0.07/1 ethylene/propylene/carbon monoxide) have been investigated and related to the polymer structure. Permeability tests have been performed at several temperatures (from 25 to about 65°C) with five different gases (oxygen, nitrogen, methane, ethane and carbon dioxide), evaluating permeabilities, diffusivities and solubilities. Their dependence on temperature was interpreted on the basis of apparent activation energies of permeation and diffusion (E_P and E_D) and of heats of solution (ΔH_S). The investigated polymer was found to be rubbery at the test temperatures (glass transition temperature is about 17°C), but the detected permeabilities are comparable to those of the glassy polymers widely used for packaging applications. Data obtained in this investigation on samples exposed to moulding temperatures (240°C) for 3 min were compared to gas permeation data (presented in a previous paper) obtained for samples exposed at that temperature for 33 min in order to assess possible effects on gas transport properties. Water vapour transport was analysed by performing both sorption (35, 34, 55 and 65°C) and permeation (35°C) experiments at several activities. The analysis of sorption isotherms revealed the occurrence of water clustering, which was confirmed by a reduction of water diffusivity as a function of water concentration in the polymer.     

Preparation and characterization of composites: Ethylene–propylene–diene terpolymer‐graft‐maleic anhydride/CaCO3

In this paper, a new method was applied to form crosslinking networks in the ethylene–propylene–diene terpolymer (EPDM) matrix with calcium carbonate(CaCO₃) particles, which were chemically treated by maleic anhydride (MAH). The tensile test showed that the tensile strength and the elongation at break of the composites were improved significantly, and when the content of CaCO₃ was about 20 wt % in the composites, the maximum tensile properties were achieved. The results of swell and solution text showed that the composites had evident crosslinking structure. The results of attenuated transmission reflectance‐Fourier transform infrared (ATR‐FTIR) spectrum proved that the Acid‐Base reaction between CaCO₃ and MAH had happened. SEM micrographs showed that the interfacial adhesion between CaCO₃ and copolymer was well. The thermogravimetric analysis curves showed that the composites had a new change in mass between 655 and 700°C, which might be the decomposition temperature of calcium maleicate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1810–1815, 2006     

Resin II: Thermal degradation studies of terpolymer resins derived from 2,2′‐dihydroxybiphenyl,urea, and formaldehyde

The terpolymer resins have been synthesized by the condensation of 2,2′‐dihydroxybiphenyl with urea and formaldehyde in the presence of 2M HCl as a catalyst and with varying molar proportions of reactants. Elemental analysis, IR, NMR and UV–Visible spectral study, and TGA–DTA analysis characterized the resins. The number average molecular weight was determined by nonaqueous conductometric titrations. Thermal studies of the resins have been carried out to determine their mode of decomposition, activation energy, order of reaction, frequency factor, entropy change, free energy, and apparent entropy change. Freeman–Carroll and Sharp–Wentworth methods have been applied for the calculation of kinetic parameters, while the data from Freeman–Carroll method have been used to determine various thermodynamic parameters. The order of thermal stabilities of terpolymers has been determined using TGA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 227–232, 2006     

Preparation of compatible blends of poly(methyl methacrylate) used in dentistry with a reactive terpolymer containing maleic anhydride and their thermomechanical characterization

This study focuses on the preparation of compatible blends with the poly(methyl methacrylate) (PMMA) using a reactive terpolymer maleic anhydride–styrene–vinyl acetate (MA–St–VA). In the first series of experiments, binary blends of the PMMA and the MA–St–VA terpolymer have been prepared in tetrahydrofurane. The PMMA and the MA–St–VA terpolymer formed the compatible blends. The effects on thermomechanical properties of MA–St–VA terpolymer ratio in the blends were studied. The glass transition temperatures (T_g), thermal expansion coefficient (α), and other thermomechanical parameters for the blends have been established by TMA method and the compatibility of two polymers has been evaluated by these TMA parameters. The addition of MA–St–VA terpolymer to PMMA made a plasticizing effect on PMMA. This effect regularly changed with the increasing of the terpolymer in the blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 363–367, 2006     

Synthesis of poly(acrylonitrile‐co‐divinylbenzene‐co‐vinylbenzyl chloride)‐derived hypercrosslinked polymer microspheres and a preliminary evaluation of their potential for the solid‐phase capture of pharmaceuticals

Poly[acrylonitrile (AN)‐co‐divinylbenzene (DVB)‐co‐vinylbenzyl chloride (VBC)] terpolymers were synthesized by precipitation polymerization in the form of porous polymer microspheres. The poly(AN‐co‐DVB‐co‐VBC) polymers were then hypercrosslinked, via a Friedel‐Crafts reaction with FeCl₃ in nitrobenzene, to provide a significant uplift in the specific surface areas of the polymers. FTIR spectra of the hypercrosslinked poly(AN‐co‐DVB‐co‐VBC)s showed that the chloromethyl groups derived from VBC were consumed by the Friedel‐Crafts reactions, which was consistent with successful hypercrosslinking. Hypercrosslinking installed a number of new, small pores into the polymers, as evidenced by a dramatic increase in the specific surface areas upon hypercrosslinking (from ～530 to 1080 m² g^?1). The hypercrosslinked polymers are very interesting for a range of applications, not least of all for solid‐phase extraction (SPE) work, where the convenient physical form of the polymers (beaded format), their low mean particle diameters, and narrow particle size distributions, as well as their high specific surface areas and polar character (arising from the AN residues), make them attractive candidates as SPE sorbents. In this regard, in a preliminary study one of the hypercrosslinked polymers was utilized as an SPE sorbent for the capture of the polar pharmaceutical diclofenac from a polar environment. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45677.     

Synthesis of sharply thermo and PH responsive PMA-b-PNIPAM-b-PEG-b-PNIPAM-b-PMA by RAFT radical polymerization and its schizophrenic micellization in aqueous solutions

Sharply thermo- and pH-responsive pentablock terpolymer with a core-shell-corona structure was prepared by RAFT polymerization of N-isopropylacrylamide and methacrylic acid monomers using PEG-based benzoate-type of RAFT agent. The PEG-based RAFT agent could be easily synthesized by dihydroxyl-capped PEG with 4-cyano-4-(thiobenzoyl) sulfanylpentanoic acids, using esterification reaction. This pentablock terpolymer was characterized by ¹H NMR, FT-IR, and GPC. The PDI was obtained by GPC, indicating that the molecular weight distribution was narrow and the polymerization was well controlled. The thermo- and pH-responsive micellization of the pentablock terpolymer in aqueous solution was investigated using ?uorescence spectroscopy technique, UV–vis transmittance, and TEM. The LCST of pentablock terpolymer increased (over 50 °C) compared to the NIPAM homopolymer (~32 °C), due to the incorporation of the hydrophilic PEG and PMA blocks in pentablock terpolymer (PNIPAM block as the core, PEG the block and the hydrophilic PMA block as the shell and the corona). Also, pH-dependent phase transition behavior shows at a pH value of about ~5.8, according to pKa of MAA. Thus, in acidic solution at room temperature, the pentablock terpolymer self-assembled to form core–shell–corona micelles, with the hydrophobic PMA block as the core, the PNIPAM block and the hydrophilic PEG block as the shell and the corona, respectively.