• Macromolecular Research
• /
• v.8 no.2
• /
• pp.89-94
• /
• 2000

A semi-interpenetrating network (IPN) was prepared for a temperature-sensitive polymer system composed of sodium alginate and poly (N, N-dimethylaminoethyl methacrylate (DMAEMA)-co-ethyl acrylamide (EAAm)). The role of sodium alginate is to provide crosslinked network and that of poly(DMAEMA-co-EAAm) is to provide temperature responsiveness to the polymer system. Semi-IPN gel shows temperature-induced swelling transition at the same temperature of the lower critical solution temperature of poly(DMAEMA-co-EAAm) and its swelling kinetics is manipulated by the control of crosslinking densitv.

• Journal of Electrochemical Science and Technology
• /
• v.10 no.2
• /
• pp.250-255
• /
• 2019

Poly(ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) show promise for improving the lithium ion battery safety. However, due to oxidation of the PEO group and corrosion of the Al current collector, PEO-based SPEs have not previously been effective for use in $LiCoO_2$ (LCO) cathode materials at room temperature. In this paper, a semi-interpenetrating polymer network (semi-IPN) PEO-based SPE was applied to examine the performance of a LCO/SPE/Li metal cell at different voltage ranges. The results indicate that the SPE can be applied to LCO-based lithium polymer batteries with high electrochemical performance. By using a carbon-coated aluminum current collector, the Al corrosion was mostly suppressed during cycling, resulting in improvement of the cell cycle stability.

• Polymer(Korea)
• /
• v.38 no.5
• /
• pp.588-595
• /
• 2014

A semi-interpenetrating polymer network (semi-IPN) hydrogel composed of crosslinked chitosan and poly (acrylic acid-co-crotonic acid) was prepared in the presence of glutaraldehyde (GA) as a crosslinker. Fourier-transform infrared, thermogravimetric analysis and scanning electron microscopy were employed to confirm the structure of the semi-IPN hydrogel. The swelling capacity of hydrogel was shown to be affected by the monomers weight ratio, chitosan content, initiator and GA concentrations. The results also indicated that the semi-IPN hydrogel had different swelling capacity at various pHs. Additionally, the swelling behavior of the hydrogel was investigated in aqueous solutions of NaCl, $CaCl_2$, and $AlCl_3$.

• Polymer(Korea)
• /
• v.36 no.4
• /
• pp.407-412
• /
• 2012

The characteristics of nylon6/ionomer semi interpenetrating networks (IPN) as a molded-in-color (MIC) compound had been studied, and comparison was made with nylon6/ionomer blends. Nylon6/ionomer semi IPN shows better homogeneity in phase morphology than nylon6/ionomer blend, and it caused better anti-scratching performance than the blend. This semi IPN structure resulted in lowered crystallization rate, increased melt viscosity and less temperature dependency of viscosity. As a result, we may expect the enhancement of melt processing characteristics in an injection molding process using nylon6/ionomer semi IPN as a MIC compound.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.6 no.5
• /
• pp.326-331
• /
• 2001

With the aim of developing of pH-sensitive controlled drug release system, a poly(Llysine) (PLL) based cationic semi-interpenetrating polymer network (semi-IPN) has been synthesized. This cationic hydrogel was designed to swell at lower pH and de-swell at higher pH and therefore be applicable for achieving regulated drug release at a specific pH range. In addition to the pH sensitivity, this hydrogel was anticipated to interact with an ionic drug, providing another means to regulate the release rate of ionic drugs. This semi-IPN hydrogel was prepared using a free-radical polymerization method and by crosslinking of the polyethylene glycol (PEG)-methacrylate polymer through the PLL network. The two polymers were penetrated with each other via interpolymer complexation to yield the semi-IPN structures. The PLL hydrogel thus prepared showed dynamic swelling/de-swelling behavior in response to pH change, and such a behavior was influenced by both the concentrations of PLL and PEG-methacrylate. Drug release from this semi-IPN hydrogel was also investigated using a model protein drug, streptokinase. Streptokinase release was found to be dependent on its ionic interaction with the PLL backbones as well as on the swelling of the semi-IPN hydrogel. These results suggest that a PLL semi-IPN hydrogel could potentially be used as a drug delivery platform to modulate drug release by pH-sensitivity and ionic interaction.

• Korean Membrane Journal
• /
• v.11 no.1
• /
• pp.8-14
• /
• 2009

The sulfonated poly(styrene-divinylbenzene-acrylonitrile) (ST-DVB-AN) composite polymer electrolyte membrane based on the original PVC film was successfully synthesized to improve oxidative stability using semi-interpenetrated polymer network (semi-IPN). Weight gain ratio after copolymerization was enhanced by the DVB and AN contents, and the sulfonated membranes were characterized in terms of proton conductivity (k), ion exchange capacity (IEC), and water uptake ($W_U$). The effect of DVB content and AN addition were thoroughly investigated by comparing the resulted properties including oxidative stability. The obtained ST-DVB-AN composited semi-IPN membranes showed relatively high proton conductivity and IEC compared with Nafion117, and greatly improved oxidative stability of the synthesized membrane was obtained. This study demonstrated that a semi-interpenetrated sulfonated ST-DVB-AN composited membrane reinforced by PVC polymer network is a promising candidate as an inexpensive polymer electrolyte membrane for fuel cell applications.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2007.05a
• /
• pp.327.2-327.2
• /
• 2007

• Polymer(Korea)
• /
• v.39 no.3
• /
• pp.426-432
• /
• 2015

Poly(ether sulfone) (PES) embedded diglycidylether of bisphenol-A (DGEBA) epoxy composites were fabricated for improving its mechanical properties and thermal stability. The mechanical properties such as tensile, flexural and impact strength of the composites changed significantly with the introduction of PES. The value of the fracture toughness of this composite also was increased remarkably about 24%. Thermal stability of PES/epoxy composites also improved 12%, which was calculated with integral procedural decomposition temperature (IPDT). From the differential scanning calorimeter (DSC) result, the curing temperature and curing heat decreased according to the increase of PES contents. These were attributed to the good distribution and the formation of the semi-interpenetrating polymer networks (semi-IPNs) composed of the epoxy network and linear PES.

• Polymer(Korea)
• /
• v.36 no.5
• /
• pp.617-621
• /
• 2012

PHEAs [${\alpha}$,${\beta}$-poly(2-hydroxyethyl-DL-aspartamides)], a class of poly(amino acid), have been widely studied as biodegradable and biocompatible polymers for potential biomedical and pharmaceutical applications. In this study, we investigated a homogeneous blend of PHEA with poly(N-vinyl pyrrolidone) (PNVP) and its semi-IPN (semi-interpenetrating polymer network) gels. Blend films were prepared by a solution casting method. The resulting blends were totally transparent over the whole composition ranges and the single $T_g$, changing monotonously with composition, was observed by DSC to confirm the miscibility between these two polymers. FTIR was used to discuss the possible hydrogen-bonding interaction between polymers. In addition, semi-IPN type gels were prepared by chemical crosslinking of PHEA/PNVP blend solution using hexamethylene diisocyanate (HMDI) as a crosslinking reagent. The prepared gel was characterized by their swelling property and morphology.

• Polymer(Korea)
• /
• v.33 no.3
• /
• pp.224-229
• /
• 2009

The dielectric properties of semi-IPN poly(phenylene oxide)(PPO) blend/$BaTiO_3$(BT) composites are investigated. The composites are fabricated via melt-mixing of crosslinker and peroxide in precursor PPO composite obtained by precipitating the suspension consisted of PPO, BT and toluene into methylethyl ketone, poor solvent of PPO. The permittivity of the precursor PPO composites shows higher value than that of integral-blended PPO composites by extruder and coincides with the theoretical value calculated by logarithmic rule of mixture. The blend of PPO and cross-linked triallyl isocyanurate is most effective for lowering the permittivity and loss tangent owing to the suppression of the orientation polarization of matrix. In contrast, 4,4'-(1,3-phenylene diisopropylidene) bisaniline, which has amine unit in its structure, increases the permittivity as well as loss tangent of the composite, but it has the ability to densify the matrix resin and the interfacial adhesion between the matrix and filler to improves flexural strength and modulus.