• Journal of Adhesion and Interface
• /
• v.12 no.4
• /
• pp.117-124
• /
• 2011

This study was made on the poly(vinyl acetate) (PVAc) and poly(vinyl acetate- ethylene) (VAE) emulsion polymer blend which used PVA as protective colloid, and the PVA used as protective colloid was existed in each emulsion film before blend and even in the film after the blend consecutively. It makes us expect excellent adhesive power among particles that form the blend. Emulsion blends with different Tg are important target of concerning, and PVAc/VAE emulsion blend suggested simple and excellent research method. As a result of blend, elongation was lowered by the increase of PVAc, and the plasticizer used in making PVAc affected on the Tg of blend and lowered Tg of VAE emulsion, and the synergy effect of two blends was seen for the tensile strength, thermal resistance, and adhesive strength.

• Explosives and Blasting
• /
• v.18 no.3
• /
• pp.15-28
• /
• 2000

국내에서는 Heavy ANFO로 더 잘 알려져 있는 Emulsion Blends는 왁스 대신 오일을 사용 하여 상온에서 펌핑이 가능하도록 한 에멀젼과 ANFO(또는 초안)의 혼합물을 일컫는다. ANFO는 저렴하고 안전하며 장약이 쉽고 밀장전되는 장점이 있지만, 내수성이 거의 없고 폭발 속도가 느리며 장약 비중이 0.75∼0.90g/cc 정도로 낮아 폭약으로서 그 위력이 작은 단점을 갖고 있다. Blends는 수용성 ANFO 입자 사이의 빈 공간을 내수성 에멀젼이 태우고 있는 형태로서 에멀젼 함량 25%부터 내수성이 나타나기 시작하여 에멀젼 함량 40% 이상에서는 완전한 내수성을 갖게 되며, 에멀젼의 함량이 증가할수록 폭발속도는 카트리지 에멀젼 폭약에 근접하게 된다. 장약 비중은 에멀젼의 함량이 증가하여 45% 근처에서 1.25∼ 1.30g/cc의 최대 값을 갖지만, 그 이상의 에멀젼 함량에서는 기폭 감도 저하로 예감제를 사용하여 비중을 감소시키는 것이 바람직하다. Blends는 자체에 물을 함유하고 있으므로 열역학적으로 계산된 단위 중량당 반응열은 ANFO에 비해 매우 적지만, 폭발속도, detonation pressure(폭굉압), borehole pressure(폭발압력) 등이 ANFO에 비해 크므로 폭발압력에서부터 암석의 파괴가 가능한 압력가지의 단위 중량당 유효한 에너지의 양은 암석의 강도가 커질수록 ANFO에 비해 매우 적지만, 폭발속도, ANFO와 비슷해진다. 따라서 장약 비중이 ANFO의 130∼145%로 높은 Blends는 동일한 천공에 더 많이 장약할 수 있어 단위 천공당 암석 파괴에 이용되는 유효 에너지의 총 양이 커지게 되므로, 공간격과 저항선을 늘릴 수 있어 총 천공수를 감소시킬 수 있다. 결론적으로, Blends의 장점은 내수성과 함께 비장약량은 비슷하거나 약간 증가하는데 비해, 천공수는 크게 감소하여 전체적으로는 발파 현장의 경제성이 향상된다는데 있다.

• Applied Chemistry for Engineering
• /
• v.3 no.4
• /
• pp.614-619
• /
• 1992

Two types of polyurethane(PU) ionomer dispersion having different type of soft segment, viz. Poly (tetramethylene adipate) glycol(PTAd), and polypropylene glycol(PPG) were emulsion blended. Viscosity of emulsion blend, mechanical, and surface properties of the emulsion cast films were determined as a function of blend composition. Mechanical properties showed a large scatter of data or negative deviation from the additivity rule, and this was attributed to the incompatibility of soft segments. Contact angle measurement indicated that air facing surface of emulsion cast film contained more of PPG PU, due probably to its smaller particle diameter compared to PTAd PU.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.15 no.2
• /
• pp.153-161
• /
• 2002

Stable polyaniline-dodecylbenzenesulfonic acid(PANI-DBSA) fully dissolved in toluene was obtained by a direct one-step emulsion polymerization technique. By using the proper molar ratio of APS/aniline monomer and DBSA/aniline monomer, the highest conductivity(7 S/cm) of PANI was obtained. The UV-Vis absorption spectrum of PANI confirmed PANI is emeraldine salt form. PANI/styrene polymers (polystyrene and styrene-butadiene copolymer) blends were prepared by mixing PANI solution with polymers in toluene. These blends exhibited the conductivity of 10$\^$-4/-10$\^$-3/ S/cm at 1 wt. % of PANI content. The mechanical property of conducting blend was decreased and TGA thermograms of conducting blends were similar to that of PANI. It had been checked that the flatness of coating layers of conducting blends decreased with increasing conducting components. It was also found that the morphology of blends was setting closer to that of PANI at higher conducting component contents.

• Journal of Pharmaceutical Investigation
• /
• v.39 no.1
• /
• pp.13-18
• /
• 2009

Docetaxel is an anticancer agent with low aqueous solubility. More extensive clinical use of this drug is somewhat delayed due to lack of appropriate delivery vehicles. An attempt was made to adopt an o/w emulsion as the drug carrier which incorporated docetaxel in the propyleneglycerol stabilized by a mixed-emulsifier system. A suitable formulation was found in this study: 10 mg/mL docetaxel, 10% (w/v) oil blend, 4% (w/v) PG, 3% (w/v) Solutol HS 15 in 2.25% (w/v) glycerol solution. The formulated emulsion has very good stability when stored at $40^{\cird}C$, and the docetaxel containment efficiency can be maintained above 95% and the mean emulsion diameter around $10{\mu}m$ for at least 3 months. The formulated emulsion is a promising carrier for docetaxel and other lipophilic drugs.

• Polymer(Korea)
• /
• v.38 no.3
• /
• pp.265-271
• /
• 2014

In order to investigate the characteristics of the gradient fluorinated polyacrylate and polyurethane latex blend films, the fluorinated polyacrylate emulsion and the polyurethane emulsion were synthesized, and then the both emulsions were blended at a series of ratios. The effects of content of the fluorinated polyacrylate on the gradient structure and surface property of the blended films were assessed by AFM, XPS, SEM-EDX and surface free energy measurements. It appeared that, while the content of the fluorinated polyacrylate latex was up to 30%, the fluorinated polyacrylate particles were selectively gathered on the film-air (F-A) and film-glass (F-G) interfaces at room temperature. When the content of the fluorinated polyacrylate was under 30%, the gradient structure of fluorinated component was not evident. The further increasing of fluorinated polyacrylate in the mixed system facilitated the formation and enlargement of gradient structure, but the adhesion of film decreased a little.

• Elastomers and Composites
• /
• v.54 no.1
• /
• pp.54-60
• /
• 2019

The rapid development of the automobile industry is an important factor that led to the dramatic development of synthetic rubber. The tread part of tire that comes in direct contact with the road surface is related to the service life of the tire. Rubber compounds used in tire treads are often blended with SBR (styrene-butadiene rubber) and BR (butadiene rubber) to satisfy physical property requirements. However, when two or more kinds of rubber are blended, phase separation and silica dispersion problems may occur due to non-uniform mixing of the rubber. Therefore, in this study, we synthesized an SBR copolymer with the same composition as that of a typical SBR/BR blend compound by controlling butadiene content during ESBR (emulsion styrene-butadiene rubber) synthesis. Subsequently, silica filled compounds were manufactured using the synthesized ESBR, and their mechanical properties, dynamic viscoelasticity, and crosslinking density were compared with those of the SBR/BR blended compound. When the content of butadiene was increased in the silica filled compound, the cure rate accelerated due to an increased number of allylic positions, which typically exhibit higher reactivity. However, the T-2 compound with increased butadiene content by synthesis less likely to show an increase in crosslink density due to poor silica dispersion. In addition, the T-3 compound containing high cis BR content showed high crosslink density due to its monosulfide crosslinking structure. Because of the phase separation, SBR/BR blend compounds were easily broken and showed similar $M_{100%}$ and $M_{300%}$ values as those of other compounds despite their high crosslink density. However, the developed blend showed excellent abrasion resistance due to the high cis-1,4 butadiene content and low rolling resistance due to the high crosslink density.

• Elastomers and Composites
• /
• v.29 no.1
• /
• pp.9-17
• /
• 1994

Methylmetharylate grafted latex(MGL) was prepared by emulsion graft copolymerization of methyl methacrylate onto natural rubber latex(NRL) by using t-butyl hydroperoxide and tetraethylene pentamine in an aqueous medium. Blending of MGL and NRL with different mixing ratio carried out and viscosity and particle size distribution of blend latex were determined. It was found that the optimum condition of mature time, vulcanizing temperature and time for preparation of blend latex films were investigated. latex films prepared by dipping process were meaured. As the reuslt, blend latex(NR-d-MG) films obtained from two-dipping system were more excellent than NR and MG film obtained from one-dipping system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.259-262
• /
• 2001

Stable polyaniline-dodecylbenzenesulfonic acid (PANI-DBSA) fully dissolved in toluene was obtained by a direct one-step emulsion polymerization technique. The polymerization of aniline was carried out in an emulsion comprising water, toluene and DBSA acting both as a surfactant and a dopant for PANI. After the proper washing process was performed, the conductivities of obtained PANI-DBSA complexes increased with increase APS/Aniline molar ratio and DBSA/Aniline molar ratio. The UV-Vis absorption spectra and TGA thermograms of PANI-DBSA complexes also supported these results. PANI-DBSA/PS blends were prepared by mixing PANI-DBSA complexes with PS in toluene. These blends exhibited electrical conductivity of 0.371S/cm at a low PANI-DBSA content (7 wt.%)

• Korea-Australia Rheology Journal
• /
• v.16 no.3
• /
• pp.135-140
• /
• 2004

Morphological and rheological properties of the poly(methyl methacrylate) (PMMA) and polystyrene (PS) blends were studied by scanning electron microscopy (SEM) and advanced rheometric expansion system (ARES). From the SEM results, the PMMA-PS blends showed dispersed morphology and the particle size of the dispersed phase was quite small (0.1~0.6 $\mu\textrm{m}$ compared with other immiscible polymer blends. Values of the interfacial tension of the PMMA-PS blend were obtained from the Choi-Schowalter and the Palierne emulsion models using the storage modulus of the PMMA and PS, and found to be 1.0 and 2.0 mN/m, respectively. The interfacial tension between the PMMA and PS was also calculated from the Flory-Huggins polymer-polymer interaction parameter ($\chi$) and found to be from 0.98 to 1.86 mN/m depending on the molecular weight and composition. Comparing the values of the interfacial tension from the Flory-Huggins polymer-polymer interaction parameter and the values measured by oscillatory rheometer, it is suggested that the interfacial tension of the PMMA-PS blend obtained from the polymer-polymer interaction parameter are in good agreement with the values obtained by rheological measurements.