Papers by Keyword: Copolymer

Abstract: Easy wrap film has been widely used a single use film for dust free storage and COVID 19 prevention during the global pandemic. In the study, natural rubber (NR) latex was chosen as the domestic raw material for a coating application. Sulfur pre-vulcanized NR (PVNR) latex was prepared and purposely planned to be mixed with PVAc-co-PVA (Polyvinyl acetate-co-polyvinyl alcohol) or copolymer as the coating product for the proposed easy wrap film. Role of ratio between polymeric materials in physical, mechanical, thermal and weather resistant properties of the prepared films was elucidated. Ability of spark resistance of the easy wrap film prepared from the polymer mixtures prepared was tested.

Abstract: The reaction of radical copolymerization of N, N-diallylaminocarboxylic acids with vinyl acetate in an aqueous and aqueous-organic medium (a mixture of methanol-water in a ratio of 70:30 mol.%) Obtained copolymers of a statistical nature. It was found that vinyl acetate under these conditions is more reactive than N, N-diallylaminocarboxylic acids. The kinetic laws of the reactions have been investigated and the structures of the copolymers have been established.

Abstract: Enhancement of surface-enhanced Raman scattering (SERS) by metal nanoparticles has attracted considerable interest on account of their widespread popularity of SERS-based measurements and devices ranging from life science until materials science. Current study focuses on noble metal SERS substrates with attempting to achieve high and enhanced effect by describe a plasmon-enhanced SERS substrate based on gold-silver, alloy-coated co-polymer (methyl methacrylate-styrene) colloidal sphere. Copolymer was synthesised via surfactant-free emulsion polymerization and was successfully produced a homogeneous colloidal spheres. The homogenous spheres of copolymer would promote periodic array upon fabrication and more, introducing the copolymer medium had improved the thermal degradation of the material compare to single polymer. Gold-silver alloy nanospheres was synthesised via one pot reduction method using citrate stabilizer. The nanoalloy obtained are well within the nanoscale domain (<100 nm) supported by the maximum surface plasmon resonance peak at 436 nm using UV-Visible spectroscopy. The perfect combination of our proposed alloy nanoparticles and copolymer present an ability to enhance Raman scattering by higher than 90 %. The region of high electron density of the substrate is expected to develop a new opportunities for SERS detections in wide analytical area.

Abstract: In this work, a new strategy for preparing antifouling surfaces by a simple dip-coating procedure is reported. Copolymers containing catechol and antifouling pendant side groups were synthesized via the free radical polymerization of a catechol-containing methacrylate monomer N-(3,4-dihydroxyphenyl) ethyl methacrylamide and three kinds of antifouling monomers separately using α,α’-azobisisobutyronitrile (AIBN) as initiator. These copolymers can assemble onto variety of materials surfaces including metals, oxides, and polymers such as PTFE using catechol groups via multivalent complex bonding. The catechol groups are helpful for adhesion of the copolymers onto the surfaces, while the other side chains endow the coatings with antifouling activity. Modification on the substrates with copolymers were verified by X-ray photoelectron spectroscopy (XPS), the images of microalgaes and zoospores setting on the substrates were taken by microscope and scanning electron microscope (SEM). The copolymer-coated surfaces, especially the surface modified by copolymer with 3-sulfopropyl methacrylate potassium salt (SPMA(K)), displayed excellent antifouling activity and fouling-release properties in settlement assay with microalgaes and zoospores.

Abstract: The synthesis, characterizations, and photovoltaic studies of copolymer based on 4,4-dodecylpentaleno[1,2-b]dithiophene (PC12PDT) and 5-octyl-5H-thieno[3,4-c]pyrrole-4,6-dione (TPD) were described. The PC12PDTTPD copolymer achieved a high open circuit voltage (V_oc) of ~ 0.8-0.9 V. Bulk-heterojunction (BHJ) solar cells were fabricated by using chlorobenzene with 1% chloronapthalene as the solvent additive. The ZnO nanoparticles, produced by flame spray pyrolysis (FSP), were dispersed in 1-butanol. After that, it was loaded into the devices along with [6,6]-phenyl-C61-butyric acid methyl ester (PC₆₁BM) used as the electron acceptor. From the results, it was found that the ZnO nanoparticles with different amount had the effect on the power conversion efficiency (PCE) of the solar cells. The PCE obtained in this study (3.33%) was found in the 5.45 wt% ZnO loaded device. This was an improvement as compared to that of the standard device (2.45%).

Abstract: The paper is dedicated to the research of calcium-phosphate coatings formed on the surface of the polymer layers (copolymer tetrafluoroethylene with vinylidene fluoride) by pulsed laser deposition. The calcium-phosphate coatings were formed using two different by composition targets. The morphology of the obtained coatings was analyzed by Scanning Electron Microscopy, the elemental composition was analyzed by Energy Dispersive Analysis, and the chemical composition was analyzed by Fourier Transform Infrared Spectroscopy.

Abstract: A fluorinated acrylate copolymer emulsion with core-shell structure was synthesized by semi-continuous emulsion polymerization using methyl methacrylate (MMA ), butyl acrylate (BA) as the raw material, hexafluorobutyl methacrylate as fluorinated acrylate monomer, ammonium persulfate (APS) as initiator, sodium dodecyl sulfate (SDS) and polyoxyethylene octyl phenyl ether (OP-10) as emulsifier and taking water as dispersion medium. The as-prepared latexes are characterized by Fourier transforms infrared (FT-IR) spectroscopy. The hydro-oleophobic of copolymer is determined by contact angle meter. The typical core-shell structure is proved by differential scanning calorimetry (DSC). The results show that the copolymer emulsion has good hydro-oleophobic when the content of hexafluorobutyl methacrylate is 15%, used the delay loading method, the water contact angle of the coating surface is 104 °, the hexadecane contact angle is 75 °. Key words: fluorinated acrylate; copolymer; emulsion; hydro-oleophobic; contact angle

Abstract: Nowadays, the earth’s available oil reserves decreases gradually while a great demand for oil is increasing.To improve oil recovery technique, the development of new profile control agent has important scientific significance and application value. A new copolymer of acrylamide (AM) and Isobutane-Ethylhexyl acrylate (2-EHA) was synthesized as profile control agent by free radical copolymerization. FT-IR and 1H-NMR were used for the structure characterization. Thermo gravimetric analysis, Core/Sand pack experiments and water drive displacement tests of copolymer particles were used to evaluate the properties. The results showed that the copolymer particles had good thermal stability, alkaline resistance, anti-salt property and excellent blocking property as profile control agent.

Abstract: A new copolymer of acrylamide (AM) and Isobutane-Ethylhexyl acrylate (2-EHA) was synthesized as profile control agent by free radical copolymerization. The copolymer composition obtained by element analysis method led to determination of reactivity ratio by employing YBR calculative method. The result indicated that the reactivity ratios of AM and 2-EHA were 0.856and 0.592 respectively. The chain segment distribution of copolymer was investigated from reactivity ratio and the microstructure of copolymer molecule was analyzed. The results showed that the ratios in feed can hardly change the chain segment distribution. The proportion of 1M1 decreased with the increase of AM in feed. AM and 2-EHA had a tendency to alternate in copolymer chain when f₁=0.286~0.375. The monomer which had a low ratio in feed inserted in copolymer chain with 1M chain segment and the other monomer was separated evenly. It can help to study copolymerization for AM and 2-EHA for industrial production in mass.

Abstract: Vinylidenefluoride (VDF) and chlorotrifluoroethylene (CTFE) copolymers were crosslinked by ultraviolet irradiation, chlorotrifluoroethylene content has a great influence on the crosslinked copolymers, high CTFE content support more joint pots, the properties of the copolymer shows higher storage modulus, the loss modulus gets smaller. The copolymer mechanical properties gets much higher.