Hydrophobically associating terpolymers were prepared by the micellar copolymerization technique using acrylamide (AM), 2-trimethylammonium
ethyl methacrylate chloride (TMAEMC) as a cationic monomer, and small amounts of 5,5,5-triphenyl-1-pentene (TP<0.5 mol-%)
as the hydrophobe. The structure of the copolymer was characterized by FT-IR and 1H-NMR. The aqueous solution properties of the terpolymers were also investigated as functions of polymer concentration, salinity,
temperature and shear rate. The results showed that the thickening behavior of these terpolymers are remarkably dependent
on both the number and length of hydrophobic segments in the copolymer chains. As expected, the terpolymers exhibited improved
viscosity enhancement properties as the concentration exceeded 0.25 g⋅dL−1, due to intermolecular hydrophobic association. Additional evidence for hydrophobic microdomains was obtained utilizing pyrene-probe
fluorescence. Additionally, the ternary copolymers showed favorable salt tolerance, temperature resistance, and recoverable
viscosity after shearing. 相似文献
A series of linear triblock terpolymers consisting of polystyrene (PS), polyisoprene (PI) and poly(methyl methacrylate) (PMMA) were examined in tetrahydrofuran (THF), a good solvent for all the blocks and in dimethylacetamide (DMA) and dimethylformamide (DMF), selective solvents for PS and PMMA. In DMA and DMF, which are both non-solvents for PI, multimolecular micelles were formed. The micelles were characterized by low-angle laser light scattering (LALLS), dynamic light scattering (DLS) and viscometry. The aggregation number of the triblock terpolymers was greater in DMF than in DMA, reflecting the higher non-solvent strength of DMF for PI. The aggregation number was also found to increase with increasing PI content of the terpolymers in both DMA and DMF. The hydrodynamic radii depended on the aggregation number of the micelle and the length of the corona forming PS and PMMA blocks. The complexity involved in studying a system consisting of three different polymer blocks is discussed in the context of the results obtained. 相似文献
Several monolithic macroporous polymer sorbents (pore size 1–2 µm) based on alkyl methacrylates and ethylene glycol dimethacrylate as a cross-linking agent were prepared by free radical copolymerization in columns 3×150 mm. The influence of compositions of the reaction mixture and porogens and the nature of the alkyl radical in a mixture of monomers on the hydrodynamic and chromatographic characteristics of the monoliths was studied. The monoliths based on n-butyl methacrylate have rigid macroporous morphology and excellent hydrodynamic characteristics (flow rate up to 5 mL min?1). The efficiency of separation of a mixture of benzene and its derivatives in the version of reversed-phase HPLC was shown to increase with an increase in the fraction of a lauryl methacrylate additive (LMA) in the reaction mixture. The maximum separation efficiency (number of theoretical plates (tp)) was 35 000 tp m?1 for the monolith based on n-butyl methacrylate with 7% LMA in the reaction mixture. 相似文献
Water-soluble N-vinylpyrrolidone-crotonic acid-2-hydroxyethyl methacrylate terpolymers, potential polymeric carriers for biologically active substances, were prepared. The composition of the terpolymers was determined, their chemical structure was confirmed, and their hydrodynamic characteristics and structural features in aqueous solutions were studied. 相似文献
Four linear and four star equimolar terpolymers based on non‐ionic hydrophilic methoxy hexa(ethylene glycol) methacrylate, ionizable hydrophilic 2‐(dimethylamino)ethyl methacrylate and neutral hydrophobic methyl methacrylate were synthesized using group transfer polymerization and investigated in aqueous dilute solutions. It was found that the (ABC)n multi‐arm star terpolymers formed unimolecular micelles comprising three centrosymmetric compartments. The position of each compartment could be determined by the block sequence (ABC, ACB or BAC) at will. On the other hand, the ABC linear counterparts formed loose associates with very low aggregation numbers. It was shown that the polymer architecture (linear versus star) greatly affected the micellization phenomena of the terpolymers in selective media.
A series of random terpolymers P2-P5 were designed and synthesized by randomly embedding 5 mol%, 10 mol%, 15 mol%and 25 mol% feed ratios of low cost 2,2-bithiophene as the third monomer to the famous donor-acceptor(D-A) type copolymer PTB7-Th(P1). All polymers showed similar molecular weight with number-average molecular weight(Mn) and weight-average molecular weight(Mw) in the range of(59-74) and(93-114) kg·mol~(-1), respectively, to ensure a fair comparison on the structure-property relationships.Compared with the control copolymer PTB7-Th, the random terpolymers exhibited enhanced absorption intensity in a wide range from400 nm to 650 nm in both solution and film as well as in polymer/PC71 BM blends. From grazing incident wide-angle X-ray diffraction(GIWAXS), compared with the regularly alternated copolymer PTB7-Th, the random terpolymers demonstrated mild structural disorder with reduced(100) lamellar stacking and slightly weakened(010) π-π stacking for the polymers as well as slightly reduced PC71 BM aggregation in polymer/PC71 BM blends. However, the measured hole mobility for terpolymers((1.20-3.73) × 104-cm2·V-1·s~(-1)) was evaluated to be comparable or even higher than 1.35 × 10~(-4) cm~2·V~(-1)·s-1 of the alternative copolymer. Enhanced average power conversion efficiency(PCE) from 7.35% to 8.11% and 7.79% to 8.37% was observed in both conventional and inverted device architectures from copolymer P1 to terpolymers P4, while further increasing the 2,2-bithiophene feed ratio decreased the PCE. 相似文献
A series of 2,4-dinitrophenyl (DNP) functionalized polypyrrole terpolymers, capable of specific binding to IgE antibodies (proteins), have been synthesized using oxidizing initiator, ammonium persulfate and were characterized by 1H-NMR, IR, DSC, Light Scattering etc. The terpolymers were composed of monomers and macromonomers: monomer (pyrrole), macromonomer A (pyrrole with pendant ethylene glycol) and macromonomer B (pyrrole with pendant DNP) with specific functionality of conductance, processiblity and binding, respectively. The terpolymers are found to be semiconductive, (5 × 10?6 S cm?1) by itself without the addition of doping agents. Molecular dynamics simulation of terpolymer shows that the DNP-(2,4-dinitrophenyl) functional group extends out from the polymer backbone and thus, is available for binding. The DNP functional groups on the terpolymer achieve steady state binding with anti-DNP IgE proteins at nanomolar concentrations in solution. The terpolymer was blended with sulfonated polystyrene and processed in fibers which exhibited effective specific binding to fluorescently tagged IgE proteins and therefore, possessed the potential to be an active component in biosensor. 相似文献
A series of terpolymers containing silyl pendant groups were prepared by free radical cross‐linking copolymerization. Et3Si and HMe2Si were covalently linked with 4‐vinylbenzyl and abbreviated as TESiMSt and DMSiMSt, respectively. Et3Si was covalently linked with 2‐hydroxyethyl methacrylate (HEMA). The silyl‐linked HEMA are abbreviated as TESiEMA. Free radical terpolymerization of the methacrylic acid (MAA) with different molar ratios of organosilyl monomers was carried out at 60–70 °C. The compositions of the polymers were determined by FT‐IR spectroscopy and 1H‐NMR. The glass transition temperature (Tg) of the polymers was determined calorimetrically. The study of DSC curves showed that incorporation of monomers with cyclic units in polymer chains increases the rigidity of terpolymers and the Tg value is subsequently increased. 相似文献
A novel poly (methyl methacrylate-co-2-methacryloyloxyethyl phosphorylcholine-co-tris(trimethylsiloxy)-3-methacryloxypropylsilane) terpolymer (PMMT) was synthesized and the anti-biofouling properties were studied in order to evaluate the potential of this silicone hydrogel to be used as contact lens material. The chemical structure was characterized by IR, 1H-NMR and elemental analysis. Poly methyl methacrylate (PMMA) and poly (methyl methacrylate-co-tris (trimethylsiloxy)-3-methacryloxypropylsilane) (PMT) were also synthesized to compare with PMMT. Protein adsorption measurement showed that for PMMT-2 membrane (MPC: 16.6 mol%), the amount of adsorbed proteins was decreased by 75.3% and 76.8% compared with PMMA and PMT membranes, respectively. SEM pictures showed clearly that PMMT films suppressed the adhesion of platelets. Water structure in polymers was determined by differential scanning calorimetry, and PMMT-2 possessed more freezing water content than PMMT-1 (MPC: 14.5 mol%). The equilibrium water content of PMMT-2 membrane reached 55%, which might offer comfortable wear feeling, and the introduction of MPC increased the wettability of the polymer surface dramatically. Both the terpolymers PMMT-1 and PMMT-2 exhibited high transparency (relatively constant at approximately 96%) in the visible light wave range. Moreover, oxygen transmissibility (Dk/t) of the terpolymers met the requirement for a lens to be worn safely overnight. It could be concluded that the novel silicone hydrogel containing MPC unit was an effective candidate material for making biomaterials, particularly for contact lenses. 相似文献