• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.374-375
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• 2006

The purpose of this paper is to investigate the propriety of biodegradable polymer pad in spite of exchanging from existing polyurethane pad used in CMP(Chemical Mechanical Planarization). Poli 400 of G&P Technology for CMP and Ellipsometer of Rudolph AutoEL-III for measurement were used in this experiment. From this experiment, it is proven that the biodegradable polymer pad is sufficiently suitable in CMP process. Therefore, it is expected that, by using the biodegrable pad CMP manufacturing process, and will be decreased. Especially, wafer scratch can be decreased.

• Polymer(Korea)
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• v.26 no.1
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• pp.145-151
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• 2002

Thermoplastic starch(TPS) was prepared from mixing starch and glycerol by twin extruder. The blends were then prepared from high density polyethylene(HDPE) and TPS. Mechanical properties, thermal properties, and morphology of the blends were investigated. Their biodegradability was also studied by using aerobic composting method(ISO14855). Tensile strength, modulus and elongation at break decreased as the content of TPS increased. In particular elongation at break decreased rapidly even at the lower content of TPS. The melting temperatures of the blends were not changed, which showed that HDPE and TPS were immiscible. The morphology of the fractured surface of blend films was investigated by scanning electron microscopy(SEM). It was found that phases were separated. After composting for 45days, the biodegradability of the blends increased as the content of TPS increased.

• The monthly packaging world
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• s.217
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• pp.45-56
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• 2011

바이오 플라스틱은 탄소저감, 인체 무해성, 플라스틱의 대체재로서 주목을 받고 있으나 아직 해결할 과제가 남아 있는 실정이다. 그 중에서 시급한 것은 (1) 가격 경쟁력 확보, (2) 내열성, 가공성, 내충격성 등 물성 개선, (3) 가공기술 개발, 응용분야 확대, (4) 분해기간 조절에 따른 유통기간이 1년 이상인 제품에 적용성 등 보완 연구, (5) 표준화, 규격기준 제정 작업 등이 필요하다. 특히 고추장, 된장, 김치, 젓갈, 치즈, 발효유 등 발효식품 포장재의 경우 제품 중에 미생물이 살아 있는 경우가 있고, 유통기한이 길기 때문에 분해기간을 장기화할 필요가 있다. 또한 유통중 및 보관 중 이산화탄소 등 가스 발생 우려가 있는 농산물, 수산물, 식품류 등은 포장재에 숨쉬는 기능 등 유사 생체막 기능 부여가 필요한 실정이다. 현재 바이오 폴리머 생산기술이 계속 발전하고 있고, 또한 가격 경쟁력도 강화되고 있어 급속한 시장 확대도 개대할 수 있는 수준이다. 석유계 플라스틱의 생산단가는 kg당 1.5~2달러 수준인 반면, 생분해 플라스틱인 PLA, 지방족폴리에스터, TPS, PHB 등은 kb당 4~5 달러 수준이다. 또한 이를 보완한 바이오매스 플라스틱은 약 2달러 수준을 유지하고 있다.

• Polymer(Korea)
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• v.24 no.1
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• pp.48-57
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• 2000

Polycaprolactone (PCL) and thermoplastic starch (TPS) blends were prepared. Mechanical properties, thermal property, water absorption, biodegradability by composting and surface morphology of PCL/TPS blends were investigated. The compositions of PCL/TPS blends were 90/10, 80/20, 70/30, 60/40, 50/50, 40/60, 30/70, 20/80, and 10/90. Strength and elongation at break decreased as the content of TPS increased, while modulus increased. DSC thermogram of TPS showed two glass transition temperatures (T$_{g}$ ) at 23$^{\circ}C$ and 126$^{\circ}C$. And TPS proved to be an amorphous polymer because there was no endothermic peak due to the melting of starch crystal. The unchanged melting temperatures and T$_{g}$ 's of PCL/TPS blends revealed that PCL and TPS were not miscible. All of the blends were found to be mechanically compatible but phase separated in each other. After 45 days composting, the biodegradability of PCL was 44% and that of PCL/TPS blends increased as the contents of TPS increased.

• Polymer(Korea)
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• v.33 no.3
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• pp.198-202
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• 2009

Oligo(ethylene terephthalate)(OET), oligo(ethylene succinate-co-terephthalate)(OEST) and oligo(butylene succinate-co-terephthalate)(OBST), which are part of the poly(ethylene terephthalate)(PET) oligomer, were synthesized. Degradation test of oligomers carried out by the presence of lipase PS. There were two objectives in the experiment: first, to measure the weight remaining of the PET oligomer as increasing degradation time, and second to examine the degradation mechanism by analyzing the resulting degraded product. In the synthesis of OEST and OBST, by controlling the feed ratio of both OEST and OBST, we were able to obtain oligomer of different composition ratios. The various composition ratios resulted in oligomer of vastly different thermal properties. We observed that both OEST and OBST were degraded using lipase PS, but as the composition of terephthalic acid was increased, the lipase PS became less effective. We confirmed that the lipase PS easily decomposed polyester of the aliphatic compound.

• Polymer(Korea)
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• v.29 no.4
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• pp.375-379
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• 2005

The morphology and therma]/viscoelastic characteristics were investigated for PLLA/MMT nanocomposite manufactured by incorporating inorganic nanosized silicate nanoplatelets into biodeuadable poly(l-lactic acid) (PLLA). The XRD difiactogram and TEM image may be regarded as a formation of homogeneously dispersed nanocomposites. The melting energy(${\Delta}H_m$) was increased during hydrolysis process because of increase of crystallinity. As MMT played a role of reinforcing agent, the storage modulus was increase in case of PLLA/MMT nanocomposite, it was well coincided with our previous results. From SEM image, many tiny pinholes formed by spinodal decomposition were observed on the surface, and the shape of nanocomposite was maintained during hydrolysis process. In this study, it was shown that the control of biodegradation rate, thermal/mechnical property was possibile by incorporating MMT.

• Polymer(Korea)
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• v.31 no.3
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• pp.233-238
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• 2007

The purpose of the study is to apply composites of poly (glycolic acid) (PGA) with [poly(R) 3-hydroxybutyrate] (P3HB) or poly (butylenes succinate- co-L-lactate) (PBSL) as medical resorbable composite materials with the complement of hydrolysis rate of each component. As a result, it was confirmed that the PBSL/PGA and P3HB/PGA composite fiber were hydrolyzed in phosphate buffer solution. Also, it has been revealed that the degradation of PBSL/PGA are accelerated due to PGA producing glycolic acid which can act as a catalyst. In addition, the hydrolysis of PBSL/PGA was found to be accelerated by the presence of lipase PS. When the PBSL/PGA composite fiber was placed in the air, not much hydrolysis has proceeded. Also, it was confirmed that the P3HB/PGA composite fiber maintained proper tensile strength in the air. Therefore, these complex fibers can be adapted to use as environmentally suitable, medically absorbable composite materials.

• Polymer(Korea)
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• v.35 no.6
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• pp.580-585
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• 2011

This article aims to enhance the biodegradability and environment-friendliness of petroleum based biodegradable poly(butylene adipate-co-succinate-co-terephthalate)(PBAST) by blending chemically modified thermoplastic starch(CMPS). CMPS is a kind of bio-based biodegradable resin which is manufactured by reacting starch with maleic anhydride(MA) in the presence of a plasticizer and a free radical initiator. The characteristic properties of PBAST/CMPS blends were investigated by observing their morphology, thermal, mechanical properties, and biodegradability. The good interfacial adhesion between the phases examined by SEM revealed that PBAST/CMPS blends were compatible blends. The tensile strength and elongation decreased with increasing CMPS content, while modulus increased. The biodegradability of the blends was much higher than that of pristine PBAST and increased with increasing CMPS contents.

• Polymer(Korea)
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• v.30 no.1
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• pp.28-34
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• 2006

A series of methoxypoly(ethylene glycol) $(MPEG)-poly(\varepsilon-co-L-lactide)$ (PCLA) diblock copolymers were synthesized by ring-opening polymerization of a mixture of $\varepsilon-caprolactone$ and L-lactide with different ratios in the presence of $Sn(Oct)_2$. The characterization of MPEG-PCLA diblock copolymers were examined by $^1H-NMR$, GPC, DSC, and XRD. Kinetic study on ring-opening polymerization of monomer mixtures was carried out in various conditions such as a variation with polymerization time, amount of catalyst, and temperature. The highest conversion obtained in 1.2 ratic of initiator venn catalyst at $110\;^{\circ}C$. The biodegradable characterization of MPEG-PCLA diblock copolymers in aqueous solution was carried out by using GPC for $1\~14$ weeks. The biodegradability of MPEG-PCLA diblock copolymers increased as the L-lactide content of diblock copolymers increased. In conclusion, we confirmed the dependence of polymerization rate according to various conditions. In addition, we can control the biodegradability of MPEC-PCLA diblock copolymers by changing the ratio of PCL and PLA block segment.

• Polymer(Korea)
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• v.30 no.1
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• pp.1-9
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• 2006

The development of functional polymeric materials for biomedical application has progressed on the basis of functionality, biocompatibility and biodegradability. In this paper we review the functional polymeric biomaterialsbased systems and propose a range of biomedical applications in the near future. These systems include the functional biodegradable polymers synthesized in our research laboratory, biodegradable polymeric materials, thermosensitive polymeric materials, cationic polymeric materials, non-condensing polymeric biomaterials, bio-polymeric DNA matrix for tissue engineering, and polymeric biomaterials for RNA interference (RNAi) technology.