• Polymer(Korea)
• /
• v.39 no.3
• /
• pp.403-411
• /
• 2015

A series of hydrophobically associating fluorinated amphiphilic polyacrylamide copolymers with remarkably high heat resistance and salt tolerance were synthesized by free radical micellar copolymerization, using acrylamide (AM) and sodium 2-acrylamido-tetradecane sulfonate ($AMC_{14}S$) as amphiphilic monomers, and 2-(perfluorooctyl) ethyl acrylate (PFHEA) as hydrophobic monomer. The structure of the terpolymer was characterized by FTIR, $^1H$ NMR and $^{19}F$ NMR. The solution properties of the terpolymers were investigated in details, and the results showed that the terpolymer solution had strong intermolecular hydrophobic association as the concentration exceeded the critical association concentration 1.5 g/L. The terpolymer solution possessed high surface activity, viscoelasticity, excellent heat resistance, salt tolerance and shearing resistance. The viscosity retention rate of copolymer solution was as high as 59.9% under the condition of fresh wastewater, $85^{\circ}C$ and a 60-days aging test.

• Journal of Environmental Science International
• /
• v.16 no.8
• /
• pp.865-872
• /
• 2007

The waterborne perfluoroacylic polyurethane composite (WFPUC) series were prepared by the emulsion polymerization (WFPUC-E) and the physical blending (WFPUC-B). WFPUC-E was prepared by polymerizing perfluoroalkyl ethyl acrylate (FA) and waterborne polyurethane (WPU), and WFPUC-B was prepared by blending FA copolymer and WPU. The structures of the synthesized WFPUC were identified by using FT-IR-ATR. The surface and thermal properties of the synthesized WFPUC were investigated by measuring contact angle, surface energy, and TGA. The surface energy of WFPUC-E was lower than that of WFPUC-B. The thermal stability of the WFPUC-B showed better than that of the WFPUC-E.

• Journal of the Korean Applied Science and Technology
• /
• v.20 no.3
• /
• pp.221-229
• /
• 2003

A copolymer ${\sim}$550cps ; $M_n$, 2590${\sim}$2850 ; and conversion, 82${\sim}$89%, respectively. It was found from the plotting of $T_g$ versus viscosity and $T_g$ versus molecular weight that viscosity increased with $T_g$ while number averaged molecular weight decreased with increasing $T_g$.

• Journal of the Korean Applied Science and Technology
• /
• v.21 no.2
• /
• pp.132-139
• /
• 2004

Film forming behavior of monodispersed model composite latexes with particle size of 190 nm, which consist of n-butyl acrylate as a soft phase monomer and methyl methacrylate as a hard phase monomer with different morphology was examined. Five different types of model latexes were used in this study such as random copolymer particle, soft-core/hard-shell particle, hard-core/soft-shell particle, gradient type particle, and mixed type particle. The film forming behavior was evaluated using pseudo on-line measurements of the cumulative weight loss, the UV transmittance, and the tensile fracture energy. Each stages of film formation I, II were not sensitive to the morphology of model latexes, but stage-ill was largely dependent on the morphology of model latexes. The chain mobility of polymer which composed the shell component was found to dominantly determine the behavior of film forming stage-III.

• Polymer(Korea)
• /
• v.33 no.5
• /
• pp.490-495
• /
• 2009

The reactive compatibilization of amorphous poly-${\alpha}$-olefins (APAO)/amorphous polyamide (aPA) blends was carried out using two kinds of reactive compatibilizers such as maleated polypropylene and ethylene-glycidyl methacrylate-methyl acrylate copolymer. The grafting reaction rates between aPA and the compatibilizers were examined using FT-IR, SEM and rheometer. The effect of the reactive compatibilization on the mechanical property of the blends was investigated with a universal testing machine. The adhesion strength of the blends including a hydrocarbon tackifier resin, C9 was also measured.

• Applied Chemistry for Engineering
• /
• v.4 no.1
• /
• pp.113-124
• /
• 1993

Thermogravimetric analysis of copolymer of acrylonitrile(95%) and methyl acrylate(5%) have been carried out to investigate the activation under $H_2O$(30%) -$N_2$atmosphere at various heating rates. The kinetic equation [$f=1-\exp(-a{\Delta}T)^b$] which was derived on the basis of the nonisothermal activation process of carbon fiber in the $H_2O$(30%)-$N_2$system showed good agreement with experimetal results. The pore volume upon conversion was in good agreement with the model of theoretical pore volume. The pore structures of the activated carbon fiber were influenced by the heating rate, activation temperature and internal-external conversions.

• Polymer(Korea)
• /
• v.31 no.3
• /
• pp.255-262
• /
• 2007

In this work, two types of copolymers are manufactured by a radical polymerization to develop a material for humid membrane. Each copolymer contains three monomers that have functions to improve humid-resistance, membrane stability, flexibility, impedance, and adhesion to the electrode. MDBAB (N,N'-dimethyl-2-methacryloxyethyl-3-bromopropyl ammonium bromide) having a salt form decreases the impedance of the humid membrane and reacts with amines to produce a cross-linking structure. HEMA (2-hydroxyethyl methacrylate) has an important role which reduces the impedance and increases the adhesion strength to the electrode. The other monomers are DAEMA (N,N'-dimethylamino ethyl methacrylate), 4-VP(4-vinyl pyridine), and 2-EHA(2-ethylhexyl acrylate) and all the monomers are formulated with several compositions to make a humid membrane. At specific composition, we could attain a satisfactory results having good performance and long term durability.

• Membrane Journal
• /
• v.18 no.3
• /
• pp.234-240
• /
• 2008

This work demonstrates the preparation of proton conducting crosslinked polymer electrolyte membranes by blending polystrene-b-poly(hydroxyethyl acrylate) (PS-b-PHEA) and poly(vinyl alcohol) (PVA) at 1 : 1 wt ratio. The PHEA block of the diblock copolymer was crosslinked with PVA using sulfosuccinic acid (SA) via the esterification reaction between -OH of membrane and -COOH of SA, as confirmed by FT-IR spectroscopy. Ion exchange capacity (IEC) continuously increased from 0.14 to 0.91 meq/g with increasing concentrations of SA, due to the increasing portion of charged groups in the membrane. In contrast, the water uptake increased up to 20.0 wt% of SA concentration above which it decreased monotonically. The membrane also exhibited a maximum proton conductivity of 0.024 S/cm at 20.0 wt% of SA concentration. The maximum behavior of water uptake and proton conductivity is considered to be due to competitive effect between the increase of ionic sites and the crosslinking reaction according to the SA concentration.

• Polymer(Korea)
• /
• v.34 no.3
• /
• pp.253-260
• /
• 2010

In this study, we prepared and evaluated a series of biocompatible and biodegradable block copolymer hydrogels with a delayed swelling property for tissue expander application. The hydrogels were synthesized via a radical crosslinking reaction of poly(ethylene glycol) (PEG) diacrylate and poly(D,L-lactide-co-glycolide)-poly(ethylene glycol)-poly(D,L-lactide-co-glycolide)(PLGA-PEG-PLGA) triblock copolymer diacrylate as a swelling/degradation controller (SDC). For the synthesis of various SDCs that can lead to different degradation and swelling properties, various PLGA-PEG-PLGA triblock copolymers with different LA/GA ratios and different PLGA block lengths were synthesized and modified to have terminal acrylate groups. The resultant hydrogels were flexible and elastic even in the dry state. The in vitro degradation tests showed that the delayed swelling properties of the hydrogels could be modulated by varying the chemical composition of the biodegradable crosslinker (SDC) and the block ratio of SDC/PEG. The histopathologic observation after implantation of hydrogels in mice was performed and evaluated by macrography and microscopy. Any significant inflammation or necrosis was not observed in the implanted tissues. Due to their biocompatibility, elasticity, sufficient swelling pressure, delayed swelling and controllable degradability, the hydrogels could be useful for tissue expansion and other biomedical applications.

• Polymer(Korea)
• /
• v.29 no.5
• /
• pp.433-439
• /
• 2005

The copolymers were prepared by the emulsion copolymerization of fluoroalky lacrylate-stearylacrylate-m-isopropenyl-${\alpha},\;{\alpha}'$-dimethylbenzyl isocyanate (TMI) in order to obtain water repellent polymers. The respective copolymerization rates of the three monomers considerably depended upon the use of the nonionic emulsifier and the nonionic-cationic mixed emusifier, and the optimum conditions were obtained. The particle sizes of the copolymers were in the range of 105 to 222nm. The particle sizes of the copolymers prepared by the use of the mixed emulsifiers were smaller than those of the copolymers prepared by the use of the nonionic emulsifier. The reactions of both TMI-N-methyl acetamide and TMI-cellobiose did not take place. However, the reaction of TMI-n-butylamine occurred. The water contact angles before and after washing three times for nylon and poly(ethylene terephthalate) (PET) fabrics coated with the copolymer prepared by the use of mixed emulsifier were about $139^{\circ}\;and\;133^{\circ}$ Therefore, the copolymer showed good durable repellency for nylon and PET.