• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.20 no.3
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• pp.77-84
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• 2014

Biodegradable nanocomposites were fabricated with poly (lactic acid) (PLA) and Nanomer$^{(R)}$ I.44P using ultrasonication (US). Processing conditions were optimized to obtain the maximum tensile properties of the nanocomposites. Poly (ethylene glycol) (PEG) was used as a plasticizer to avoid the brittleness of nanocompsoties. In order to disperse nanoclay into the PLA matrix, PEG and Nanomer$^{(R)}$ I.44P were firstly mixed and dispersed in the chloroform and followed by ultrasonication for 1 min With 10% PEG 400, tensile stress and Young's modulus of the nanocomposites decreased from 53.5 MPa and 2225 MPa to 37.0 MPa and 1757 MPa, respectively, while the elongation was increased from 4% to 21%. Tensile stress, Young's modulus, and elongation of nanocomposites were also increased with nanoclay concentration up to 2% (w/w) and were decreased with further increase in the nanoclay concentration. Transmittance of nanocomposites were significantly decreased from 62.5% for pure PLA film to 7.8% for 5% nanoclay containing nanocomposites. Water vapor permeability of the nanocomposites was also significantly decreased with nanoclay concentration and the minimum WVP of $3.5{\times}10^{-11}g{\cdot}m/m^2{\cdot}s{\cdot}Pa$ was obtained with 5% (w/w) nanoclay concentration. The PLA/Nanomer$^{(R)}$ I.44P nanocomposites showed a great potential as a environmental friendly food packaging material.

• Polymer(Korea)
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• v.33 no.5
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• pp.469-476
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• 2009

In this study, biodegradable superporous hydrogels(SPHs) with fast swelling and superabsorbent properties were prepared using biodegradable crosslinkers and their physicochemical properties were characterized. A biodegradable crosslinker (PLA-PEG-PLA DA) was synthesized by a ring opening polymerization of D,L-lactide (LA) using hydrophilic poly(ethylene glycol) as a macroinitiator, followed by diacrylation of the end groups for the introduction of polymerizable vinyl groups. Various kinds of hydrogels with different chemical compositions were prepared and characterized in terms of swelling ratio, swelling kinetics, and biodegradation properties. The synthetic results were confirmed by $^1H$-NMR, FT-IR and GPC measurements, and the porous structures of the prepared SPHs and their porosities were identified by a scanning electron microscope and mercury porosimetry, respectively. The physicochemical properties of SPHs could be controlled by varying their chemical compositions and their cytotoxicity were found to be very low by MTT assay.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.299.2-300
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• 2003

Various bupivacaine-Ioaded microspheres were prepared with poly (d,l-Iactide) (PLA) by solvent extraction method. The internal solution of polymer(PLA R104) and drug in glacial acetic acid was introduced into the external phase of polyvinylpyrrolidone (PVP K-30) in polyethyleneglycol (PEG), and emulsified to be an oil-in-oil (o/o) emulsion. The o/o emulsion was poured to the buffer solution. (omitted)

• Polymer(Korea)
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• v.34 no.3
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• pp.274-281
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• 2010

In this study, PEG-PLA(or PLGA) amphiphilic di-block copolymers were synthesized by ring opening polymerization of D,L-lactide(or glycolide) and applied to polymeric micelle system for solubilization of a rosiglitazone as diabetes drug. The drug could be efficiently loaded into the polymer micelle by solid dispersion technique, and the drug-loaded micelles were characterized and evaluated as a drug delivery carrier by fluorescence spectrometer, DSC, and DLS measurements. The colloidal stability of drug loaded micelles in aqueous media could be enhanced by addition of 2-hydroxy-N-picolylnitinamide as a hydrotropic agent. The polymer micelles also showed biocompatible and nontoxic properties in vitro cell viability using MTT assay, and the drug loaded micelles were observed to be more effective than free drug for decreasing glucose in blood of rats.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2016.10a
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• pp.279-279
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• 2016

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.550-553
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• 2000

The polymeric matrices made with poly(D,L-lactide-co-glycolide) were prepared using copolymer of poly(D,L-lactide) and poly(ethylene glycol) for application of drug delivery systems. Catalyst made use of stannous actoate. Particle size were differ greatly$(435.3{\pm}11.2{\sim}2284.1{\pm}188.5)$ that nanoparticle made use of according to solvent of various kinds. Polymer could a sharp distinction with copolymerized among LE-1, LE-2 and LE-3 of PLA and PEG of content that to examine $^1H-NMR$ of copolymer make refine and reprecipitation. Drug delivery effect at PLGA nanoparticle : PLA amount more then proved highly drug delivery amount that each LE-1, LE-2, LE-3, drug and solvent was 40mg, 20mg and 10mg. Drug delivery effect proved higher 20mg that change(10mg, 20mg, 40mg) at drug feeding amount with LE-2. The first a lot of drug proved delivery. LE-3 most lactide content proved much delivery since biodegradable on PLGA copolymer result from lactide. Also biodegradable rate was highest at LE-3 much of lactide content, because influence at biodegradable effect of lactide by inclusive of soft PEG.

• Elastomers and Composites
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• v.55 no.4
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• pp.347-353
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• 2020

Stearic acid (SA), polyethylene glycol (PEG), and malic acid (MA) have been used to modify the surface of waste gypsum to develop corresponding poly (butylene adipate-co-terephthalate) (PBAT) composites. According to the mechanical properties, MA-treated gypsum (MA-gypsum) showed the best performance, whereas SA-gypsum showed the worst performance. In contrast to SA and PEG (having -COOH and -OH as polar functional groups, respectively), the presence of both -OH and -COOH in MA is responsible for the superior surface treatment of gypsum and its better dispersion in the polymer matrix (as revealed by FE-SEM analyses). The presence of long aliphatic chain in SA is supposed to inhibit the dispersion of SA-gypsum. Further, the performance of MA-gypsum/PBAT was enhanced by adding polylactic acid (PLA). The maximum optimized contents of MA-gypsum and PLA are 20 and 7.5 wt% for developing a high-performance PBAT composite.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.845-846
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• 2005

• Journal of Adhesion and Interface
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• v.20 no.4
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• pp.140-145
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• 2019

In view of environmental considerations, the control of carbon dioxide (CO₂) and volatile organic compounds (VOCs) is one of important issues in the film and coating industries. Therefore, UV-curable system has been developed due to minimize emissions of VOCs and reduce CO₂ emission due to low energy consumption from fast curing. Also, biodegradable polymers economically are attractive because of environmental and economic concerns associated with huge waste plastics. In this study, UV-curable polyurethane acrylates with different compositions of biodegradable polylactide (PLA) diol and poly(ethylene glycol) as diols were synthesized and curing reaction of their end-capped acrylates was performed by UV exposure. Tensile strength, elongation, and Tg of the UV-cured polyurethane acrylates increased with PLA diol content in the diol while their hydrophilicity and thermal stability increased with the PEG content. These results indicated a property of UV-cured polyurethane acrylates could be controlled by environment-friendly diols.