• Composites Research
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• 제27권3호
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• pp.83-89
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• 2014

본 연구는 엔지니어링 플라스틱인 Polybutylene terephthalate(PBT)에 첨가물을 넣어 강도와 열전도성, 열충격내구성을 개선시키는 것을 목적으로 한다. 그에 따라 PBT에 유리섬유(Glass Fiber)와 Boron nitride(BN)을 복합적으로 첨가하여, 각각의 조성비에 따른 기계적 특성과 열전도 특성변화를 실험적으로 분석하였다. 시험 결과 BN의 함유량이 증가함에 따라 열전도도는 증가하였고, 기계적 강도는 작아졌다. 열충격싸이클을 가한 결과, 비충전 PBT는 파단 신장률이 작아졌으나 충전 PBT는 강도와 열전도율이 별다른 성질변화가 거의 없었다. BN의 첨가에 따라 PBT 복합재의 열전도도도는 크게 향상되었다.

• Fibers and Polymers
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• 제7권4호
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• pp.358-366
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• 2006

Thermotropic liquid crystal polymer (TLCP)-reinforced poly(butylene terephthalate) (PBT) composites were prepared by melt processing. The improvement in the mechanical properties and the processability of the PBT/TLCP composites was attributed to the reinforcing effect by TLCP phase and its well distribution in the PBT matrix. X-ray diffraction results demonstrated that a slow cooling process leads to the thicker lamellar structures and the formation of more regular crystallites in the composites. The incorporation of TLCP improves not only the tensile strength and flexural modulus but also the heat distortion temperature (HDT) of the PBT/TLCP composites. The HDT values of the composites were dependent on TLCP content. The improvement in the HDT values of the PBT/TLCP composites may be explained in terms with the increased flexural modulus, the development of more regular crystalline structures, and the enhancement of the ability of the composites to sustain the storage modulus by TLCP phase. In addition, the simple additivity rule makes it possible to predict the HDT values of the PBT/TLCP composites.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 춘계학술대회 논문집
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• pp.159-165
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• 2004

The shrinkages of injection molded parts are different in molding operational conditions and mold design. It also differs from resins. The shrinkages of injection molded parts for PBT (polybutylene terephthalate), PC (polycarbonate),and glass reinforced PBT and PC have been studied for various operational conditions of injection molding. The part shrinkage of crystalline polymer, PBT was higher than that of amorphous polymer, PC by about two times. The part shrinkages of both polymers decreased as glass fiber content increases. Higher Injection temperature and lower injection pressure resulted in a higher shrinkage in both PBT and PC resins. As mold temperature increases the part shrinkage of PC decreased. However, the part shrinkage of PBT increased as mold temperature increases. The part shrinkage of both PBT and PC resins decreased as gate size increases since the pressure delivery is mush easier for a larger gate size. The part shrinkage of flow direction was less than that of the perpendicular direction to the flow for both pure and glass fiber reinforced resins. The part shrinkage at the position close to the gate was less than that of the position far from the gate.

• Macromolecular Research
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• 제13권1호
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• pp.19-29
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• 2005

Polymer composites based on a thermotropic liquid-crystalline polymer (TLCP) and poly(butylene terephthalate) (PBT) were prepared using a melt blending process. Polymer composites consisting of bulk cheap polyester with a small quantity of expensive TLCP are of interest from a commercial perspective. The interactions between the PBT chains and the flexible poly(ethylene terephthalate) (PET) units in the TLCP phase resulted in an improvement in the compatibility of PBT/TLCP composites. TLCP droplets deformed and fragmented into smaller droplets in the PBT/TLCP composites, which resulted in TLCP fibrillation through the effective deformation of the TLCP droplets. The nucleation activities of the PBT/TLCP composites increased by adding even a small amount of the TLCP component.

• 소성∙가공
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• 제13권6호
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• pp.515-521
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• 2004

The shrinkages of injection molded parts are different in molding operational conditions and mold design. It also differs from resins. The shrinkages of injection molded parts fur PBT (polybutylene terephthalate), PC (polycarbonate), and glass reinforced PBT and PC have been studied for various operational conditions of injection molding. The part shrinkage of crystalline polymer, PBT was higher than that of amorphous polymer, PC by about two times. The part shrinkages of both polymers decreased as glass fiber content increases. Higher injection temperature and lower injection pressure resulted in a higher shrinkage in both PBT and PC resins. As mold temperature increases the part shrinkage of PC decreased. However, the part shrinkage of PBT increased as mold temperature increases. The part shrinkages of PBT and PC resins decreased as gate size increases since the pressure delivery is mush easier for a larger gate size. The part shrinkage of flow direction was less than that of the perpendicular direction to the flow for both pure and glass fiber reinforced resins. The part shrinkage at the position close to the gate was less than that of the position far from the gate.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1987년도 제2차학술발표초록집
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• pp.35-35
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• 1987

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2002년도 봄 학술발표회 논문집
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• pp.163-166
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• 2002

PBT 섬유에 관한 연구[1-4]는 주로 섬유화 가능성에 관한 것을 타진하는 것으로써, 그 중 Spruiell[1]은 권취속도 1000-5600m/min에서 얻어진 PBT 필라멘트의 구조와 물성에 대하여 연구하였다. 그는 방사시 온라인상의 직경변화, 온도, 하중의 변화에 대해 연구하였으며, 방사선상에서 PET에 비해 결정화속도가 매우 빠르다고 보고하였다. 저자 등[2-3]은 권취속도 1-8km/min까지 변화시켜 얻은 PBT섬유의 구조에 관한 연구에서 6km/min 이상의 속도에서 얻은 경우 초기탄성률이 최고값을 가지며 그 이후 변화가 없음을 확인하였다. (중략)

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1995년도 춘계학술발표회 프로그램 및 초록
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• pp.43-43
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• 1995

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2002년도 봄 학술발표회 논문집
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• pp.41-44
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• 2002

블렌딩이나 공중합체의 합성은 한가지 또는 모든 구성성분 고분자의 단점을 보완하면서 효과적인 물성 발현을 위해 연구되어 왔다. 특히 방향족 폴리에스테르계 고분자들 사이에서는 PET/PEN, PEN/PHN, PBT/PBN, 또는 PET/PBT 등의 공중합체가 보고되고 있다[1-3]. 한편, poly(trimethylene terephthalate)(PTT)는 최근 섬유로 방사되어 카펫, 의류 등으로 응용된 이후 PTT를 주성분으로 하는 bicomponent 멜트블로운 부직포[4], 염색[5] 등의 연구가 활발히 이루어지고 있다. (중략)

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1998년도 가을 학술발표회논문집
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• pp.268-271
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• 1998

Poly(butylene terephthalate) (이하 PBT)는 두 종류의 결정형태를 가지는 고분자로 널리 알려져 있다. 이 두 가지 결정형태를 각각 $\alpha$상 결정과 $\beta$상 결정이라고 하는데, 이 두 결정형은 방사나 연신 또는 열처리 등의 공정에 의하여 생성되기도 하고 $\alpha$-$\beta$상 간 전이를 일으키기도 한다[1],[2]. (중략)