• Polymer(Korea)
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• v.27 no.1
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• pp.3-8
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• 2003

Polysiloxanes with methacrylate groups at both terminals were synthesized by a hydrosilylation reaction between allyl methacrylate and hydride-terminated polysiloxanes. The polysiloxane methacrylates with high molecular weights could be prepared through the reaction of polysiloxane methacrylates and octamethylcyclotetrasiloxane with an acid catalyst. The structures of the prepared polysiloxane methacrylates were verified by $^1$H- and $^{29}Si-NMR.$ The polysiloxane methacrylates were freely miscible with silicone oils. Polysiloxane films with microphase-separated liquid silicone oil were prepared by photo-crosslinking the mixture of polysiloxane methacrylates and silicone oil. Scanning electron microscopy (SEM) of the films showed that the size of silicone oil droplets became smaller with a lower loading of silicone oil, lower molecular weight of polysiloxane methacrylate, and lower molecular weight of silicone oil.

• Polymer(Korea)
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• v.28 no.1
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• pp.77-85
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• 2004

It has been widely used ultra high molecular weight polyethylene (UHMWPE) for the biomaterials due to its excellent mechanical properties and biocompatibility. In the case of blend of UHMPE with another polymeric biomaterials, however, UHMWPE might have low blend compatibility due to surface inertness. In this study, in order to improve the mechanical properties of poly(methyl methacrylate) (PMMA) bone cement by means of the impregnation of UHMWPE powder, we developed the novel surface modification method by the mixture of methyl methacrylate (MMA) and xylene. We investigated the variation of composition of MMA/xylene. It was confirmed by the analysis of Fourier transform infrared-attenuated total reflectance, scanning electron microscope, universal transverse mercator, and digital thermometer. The maximum mechanical strength of surface modified UHMWPE powder impregnated PMMA bone cement compound was observed the ratio of 1 : 1 (v/v％) MMA/xylene. Also its curing temperature decreased from 103 $^{\circ}C$ to 58 ∼ 73 $^{\circ}C$ The mechanism of surface modification of UHMWPE powder by the mixture of MMA/xylene has been proposed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.147-147
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• 2004

폴리메틸메타크릴레이트(polymethylmethacrylate, PMMA)는 아크릴레이트계 고분자이자 열가소성 플라스틱으로써 LCD용 도광판, 콘택트렌즈, 치과용 레진, DVD 디스크용 소재, 나노임프린트용 피가공재, 나노리소그래피 공정용 레지스트 등 많은 분야에서 활발히 사용되고 있다. PMMA 와 같은 점소성 점탄성 소재의 기계적 성질 측정 및 가공을 위해서는, 응력완화 (stress relaxation), 크립 (creep)등과 같은 시간의존적 변형거동에 대한 연구가 선행되어야 한다.(중략)

• Polymer(Korea)
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• v.28 no.6
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• pp.509-518
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• 2004

Microdomain structures and crystallization behavior of the binary blends consisting of an asymmetric block copolymer and a homopolymer were investigated using small-angle X-ray scattering (SAXS), optical micro scope (OM) and differential scanning calorimetry (DSC). Poly(methyl methacrylate)-block-polystyrene block copolymer (PMMA-b-PS) (weight fraction of PMMA =0.53) was mixed with low molecular weight poly(vinylidene fluoride) (PVDF). As the PVDF concentration was increased, the morphological change from a lamellar to a cylindrical structure occurred. The crystallization of PVDF significantly disturbed the orientation of the pre-existing microdomain structure, resulting in a poorly ordered morphology. In the blends, PVDF exhibited unique crystallization behavior due to the PMMA block which is preferentially miscible to PVDF and the space constraint imposed by the microdomains.

• Polymer(Korea)
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• v.35 no.6
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• pp.531-536
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• 2011

Homopolymer distribution in block copolymer/homopolymer blends was investigated as a function of homopolymer concentration and homopolymer molecular weight. The deuterated poly(methyl methacrylate) or polystyrene was blended with a deuterated polystyrene-poly(methyl methacrylate) diblock copolymer up to a concentration of 20 wt%. Samples were characterized by small-angle X-ray scattering (SAXS), neutron reflectivity and transmission electron microscopy. The block copolymer with a thin-film geometry formed alternating lamellar microdomains oriented parallel to the substrate surface. By adding the homopolymer, the microdomain structure was significantly disturbed. As a consequence, a poorly ordered morphology appeared when the homopolymer concentration exceeded 15 wt%. Increasing the homopolymer concentration and/or the homopolymer molecular weight caused the microdomains to swell less uniformly, resulting in segregation of the homopolymer toward the middle of the microdomains.

• Elastomers and Composites
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• v.43 no.3
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• pp.157-165
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• 2008

Suspension polymerization was carried out to synthesize poly(butyl methacrylate) (PBMA) composite particles containing carbon black. Water was selected as a reaction medium, hydrophobic silica as a stabilizer and azobisisobutyronitrile as an initiator. Concentration of stabilizer was varied from 0.67 to 2.55 weight% with respect to the water, and that of initiator was varied from 0.25 to 3.00 weight% with respect to the butyl methacrylate (BMA) monomer. All polymerization reactions were conducted at 75$^{\circ}C$. It is found that stabilizer concentration has no impact on reaction kinetics, while an increase in initiator concentration enhances polymerization reaction rate. Increase of carbon black concentration from 1 to 3 to 5 wt% into PBMA displayed progressive decrease in reaction conversion. The particle diameter of PBMA composite particles containing carbon black was found to be between 5 and 30 ${\mu}m$. Glass transition was determined to range from 23.8 to 24.7$^{\circ}C$, irrespective of variation in the concentration of stabilizer, initiator or carbon black.

• Polymer Science and Technology
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• v.3 no.1
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• pp.13-23
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• 1992

• Journal of the Korean Chemical Society
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• v.62 no.6
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• pp.433-440
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• 2018

The pyrolysis has been universally applied to recycle the waste artificial marble. However, the existing heat treatment equipment has relatively low heat transfer efficiency into the inner part of the waste artificial marble. Besides, it leads to unnecessary excessive gas during the partial carbonization of the polymethyl methacrylate (PMMA) and raises the risk of fire due to heat at an extremely high temperature. This study suggests the process of pyrolysis at the formation state after adding the starch to waste artificial marble to overcome above-mentioned problems. As the result of experiments, this method showed that the pyrolysis of waste artificial marble was greatly improved at comparatively low temperature condition of $350^{\circ}C$. Moreover, it also manifested the effect on securing the stability and energy savings necessary for the recovery of methyl methacrylate (MMA) and ${\alpha}$-alumina (${\alpha}-Al_2O_3$).

• 한국전기화학회:학술대회논문집
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• 2001.10a
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• pp.34-34
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• 2001

• Journal of the Microelectronics and Packaging Society
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• v.10 no.4
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• pp.21-27
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• 2003

The copolymers with various composition of methyl methacrylate (MMA), ethyl methacrylate (EMA), methacrylic acid (MA) and hydroxyethyl methacrylate (HEMA) were synthesized for capacitive humidity sensitive materials. The capacitive humidity sensor consisted of a polymethacrylate film coated on both sides with gold electrode. Capacitance versus relative humidity increased with HEMA content in the copolymer. In the case of self-crosslinkable MMA/MA/HEHA= 40/10/10, the average capacitance at 30%RH, 60%RH and 90%RH are 102, 134 and 166 pF, respectively. And also, the hysteresis, temperature cycle and long-term stability were evaluated as a capacitance humidity sensor.