Series Of Methacrylate Copolymers Research Articles

Fabrication of ultrafiltration membranes based on methacrylate copolymers containing quaternary ammonium and PEG units for dye removal

Abstract Phase inversion involves in a complex process due to numerous factors affecting the membrane formation. Among them, polymer chain entanglement from polymeric membrane materials plays a critical role in regulating membrane structure and is still worth further exploration. Herein, a series of methacrylate copolymers with different contents of poly(ethylene glycol) methacrylate (PEGMA) were designed and synthesized, and ultrafiltration membranes cast from these copolymers were systematically investigated regarding structural evolution and filtration performance. Surface zeta potential of membranes gradually transformed from positive to negative with the increasing PEGMA content due to nonsolvent-induced surface migration of element oxygen, and meanwhile the transformation from finger-like pore structure to sponge-like pore structure in the support layer was observed, which could be attributed to chain entanglement of the PEGMA-rich copolymer. Filtration experiments indicated that sponge-like membranes possessed better separation effect of Victoria blue B compared with finger-like membranes, and the optimized mPP40-15 % showed a retention rate of 99.55 % and permeance of 110.26 L m−2 h−1 bar−1 and displayed good selective separation of dye/salt mixture. Besides, sponge-like membranes also exhibited easy regeneration, anti-fouling property and filtration stability. This work will provide guidance for modulating membrane structure and offer an alternative material for membrane separation in handling dye wastewater.

Influence of Polymer Composition and Substrate on the Performance of Bioinspired Coatings with Antibacterial Activity

A series of methacrylic copolymers bearing thiazolium cationic groups and catechol moieties were evaluated as antibacterial coatings on a variety of materials including aluminum and plastics such as polycarbonate, poly(methyl methacrylate), and silicone rubber. The thermal properties of the copolymers were first studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The cationic copolymers were thermally stable up to 200 °C and presented glass transition temperatures values well above 100 °C; thus, an acceptable thermal behavior for typical biomedical applications. The cationic copolymers with variable content of the adhesive anchoring N-(3,4-dihydroxyphenethyl) methacrylamide (DOMA) units were coated onto the metal and polymeric substrates by drop casting and the adhesive properties of the obtained coatings were further evaluated as a function of DOMA content and substrate. Optical profilometry, attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectra, and antimicrobial studies reveal that the coatings adhere stronger to metal substrates than to the polymeric substrates. The copolymers with higher content of DOMA, 24 mol.%, resist solvent erosion treatment when coated onto all substrates and exhibit antimicrobial activity against Gram-positive S. aureus bacteria after this erosion treatment. In contrast, copolymers with low content, 9 mol.% of DOMA, only remain attached onto the aluminum metal substrate after solvent treatment, while on polymeric substrates the coatings are almost removed and do not show any efficacy against S. aureus bacteria.

Polyhedral Oligomeric Silsesquioxane Containing Copolymers for Negative‐Type Photoresists

AbstractSummary: A series of methacrylate copolymers containing polyhedral oligomeric silsesquioxane (POSS) was synthesized from the free radical copolymerization of methacrylic acid, methyl methacrylate, and isobutyl propylmethacryl polyhedral oligosilsesquioxanes, and then were modified with glycidyl methacrylate to serve as negative‐type photoresists. The UV/Vis spectroscopy reveals that the incorporation of POSS moiety into the copolymer results in a slight decrease in transparency from 99 to 92.5% (at wavelength = 365 nm). The photosensitivity in terms of resist sensitivity (D), contrast (γ), and photopolymerization rate are significantly increased with increase in the POSS content. In addition, the induction time is reduced from 0.520 to 0.515 min after incorporating the POSS unit based on photo‐DSC analyses. These observed results can be rationalized as due to hydrogen bonding interactions between siloxane and hydroxyl groups in copolymers which tend to attract the methacrylate double bonds surrounding POSS units to crosslink, thereby enhancing the photopolymerization rate and sensitivity. We further evaluate the lithographic property of a photoresist under a collimated exposure.Compact double bonds zone induced via hydrogen bonding.magnified imageCompact double bonds zone induced via hydrogen bonding.

Polymethacrylate Copolymers Containing 4,5‐Dicyanoimidazole‐Based Chromophores and their Nonlinear Optical Behavior

AbstractSummary: Two series of methacrylate copolymers were prepared, based on two new nonlinear optically (NLO) active chromophores 2‐[4‐(N‐methacryloyloxyethyl‐N‐methylamino)phenylazo]‐4,5‐dicyanoimidazole (chromophore A) and 1‐ethyl‐2‐[4‐(N‐methacryloyloxyethyl‐N‐methylamino)phenylazo]‐4,5‐dicyanoimidazole (chromophore B). Second order NLO properties of the two series of copolymers (A or B as monomer and methyl methacrylate as the comonomer) were investigated by SHG procedures at the fundamental wavelength 1368 nm; d33 values in the range 0.2–3.3 pm · V−1 were obtained, depending on the chromophore and on its molar content. The dependence of d33 on the molar content of chromophore was investigated in the two cases. magnified image

Gas Transport Properties of Poly(2-ethoxyethyl methacrylate-co-2-hydroxyethyl methacrylamide)

A series of methacrylic copolymers was prepared by radical polymerization of the monomers 2-ethoxyethyl methacrylate and 2-hydroxyethyl methacrylamide and a small quantity of a cross-linking agent ethylene glycol dimethacrylate. Water swelling of the membranes, mechanodynamical analysis, density measurements, and ATR-FTIR studies were performed on the copolymers. High vacuum pressure techniques were used to evaluate the flow of He, O2, N2, CO2, CH4, CH3CH3, and CH2CH2 through these membranes, and solubility, diffusivity, and permeability coefficients were determined. The effect of the increase of the amount of methacrylamide in the copolymer on transport properties, glass transition, fractional free volume, cohesive energy density, and specific interactions has been studied and is reported in this work.

Preparation and lithographic performance of novel copolymers having acid labile pendant alicyclic ether moieties

A series of methacrylic copolymers derived from methacrylic acid (MAA), methyl methacrylate (MMA), n-butyl methacrylate (BM), and bornyl methacrylate (BMA) with various feed molar ratios was synthesized. In order to introduce acid labile alicyclic ether groups, the pendant carboxyl groups of copolymers were further functionalized with unsaturated alicyclic ethers of 2,3-dihydrofuran (DHF), 3,4-dihydro-2H-pyran (DHP), and 3,4-dihydro-2-methoxy-2H-pyran (DHMP). The existence of alicyclic bornyl groups was found to increase the thermal and plasma etching resistance of polymers but to decrease the sensitivity and contrast. Copolymers having pendant carboxyl groups can be crosslinked in the presence of photoacid after sufficient heat treatment. Acid catalyzed dehydration of pendant carboxylic acids may also cause the crosslinking of polymers. The thermogravimetric properties of copolymers, exposure characteristic curves and lithographic evaluation of the positive tone photoresist were all investigated. A line and space pattern resolution of 0.3 μm was also achieved.