• Polymer(Korea)
• /
• v.29 no.3
• /
• pp.237-241
• /
• 2005

Photocurable pentaerythritol modified hyperbranched acrylates were prepared from trimellitic anhydride, glycidyl methacrylate and pentaerythritol derivatives. Thermal stability obtained by using TGA showed that HBMA-1 was superior to the others. Hardness, abrasion resistance and tensile strength of HBMA-1 showed that Hey were also superior to the others. Value of yellow index of HBMA-1 showed the lowest.

• Fibers and Polymers
• /
• v.7 no.4
• /
• pp.328-332
• /
• 2006

Poly(ethylene terephthalate) (PET) and poly(ethylene glycol) (PEG) copolymers cross-linked with pentaerythritol, a four-way cross-linker, are prepared to compare their mechanical and shape memory properties with the one cross-linked by glycerol. Composition of PEG and pentaerythritol is varied to search for the one with the best mechanical and shape memory properties. The highest shape recovery rate is observed for the copolymer composed of 30 mol% PEG-200 and 2.5 mol% pentaerythritol. Four-way cross-linking by pentaerythritol significantly improves shape recovery rate and retention of high shape recovery rate after repeated use compared to the one cross-linked by glycerol, a three-way cross-linker, and difference and advantage of additional cross-linking point are discussed.

• 월간산업보건
• /
• s.266
• /
• pp.10-12
• /
• 2010

Pentaerythritol에 대한 TLV-TWA로 10 mg/$m^3$이 권고되고 있으며, 이 수치는 망막이나 점막 염증 발생의 잠재성을 최소화하기 위해 설정되었다. Pentaerythritol은 모든 노출 경로에서 약한 독성을 유발하는 물질로 간주되고 있고, 작업환경이 정상적으로 관리되고 있으면 건강상의 큰 문제는 없는 것으로 알려져 있다. 일상적인 온도와 압력 조건 하에서 pentaerythritol의 증기 유해성은 거의 없다. 피부 (Skin), 감작제 (SEN), 발암성에 대한 경고주석과 TLV-STEL에 대한 기준은 유효한 자료가 충분히 제공되고 있지 않아 설정되지 않고 있다.

• Korean Chemical Engineering Research
• /
• v.49 no.4
• /
• pp.411-416
• /
• 2011

NCO terminated polyurethane prepolymers were synthesized from isophorone diisocyanate(IPDI), polycarbonate diol(PCD) and dimethylol propionic acid(DMPA). Subsequently, acrylic terminated prepolymers were prepared by capping the NCO groups of polyurethane prepolymers with different moles of pentaerythritol triacrylate (0~0.024 moles) as a acrylate monomer. The average particle size of the acrylic terminated polyurethane solutions was increased with increasing PETA contents. Also, the prepared coating films showed better abrasion resistance and pencil hardness than pure waterborne polyurethane.

• Korean Chemical Engineering Research
• /
• v.46 no.6
• /
• pp.1039-1042
• /
• 2008

In order to increase a functionality, OH value, for a recycled polyol prepared from the glycolysis reaction of a waste polyurethane rigid foam(PUR), the effect of an addition of pentaerythritol(PEN, functionality(f)=4) or sorbitol(SOR, f=6) to the its glycolysis reactor on the prepared polyol functionality and the mechanical properties of the polyurethane prepared using it was investigated. The OH values increased from 2.2 for a virgin to 2.8 for the recycled polyol. There was an increase in the mechanical properties including dimensional stability for PUR prepared using the recycled polyol, in which the increased OHs provided higher crosslinking density during PUR synthesis. In addition, the amount of the recycled polyol in the polyol system increased to from 8 to 20 wt% to give better mechanical properties to the PUR.

• Korean Chemical Engineering Research
• /
• v.50 no.2
• /
• pp.191-197
• /
• 2012

Acrylic terminated polyurethane prepolymers were synthesized by capping the NCO groups of polyurethane prepolymers, prepared from isophorone diisocyanate (IPDI), polycarbonate diol (PCD) and dimethylol propionic acid (DMPA), with pentaerythritol triacrylate (PETA). Subsequently, silylated acrylic terminated prepolymers were prepared by capping the NCO groups of acrylic terminated polyurethane prepolymers with different types of silane coupling agents, glycidoxypropyl trimethoxysilane (GPTMS) or aminopropyl triethoxysilane (APS). The average particle size of pure waterborne polyurethane solution, measured by the dynamic light scattering method, was increased from 14.3 nm to 208.6 nm by adding PETA and APS. Also, the coating film of silylated acrylic terminated waterborne polyurethane showed better abrasion resistance and pencil hardness than that of pure waterborne polyurethane.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.9
• /
• pp.2459-2466
• /
• 2010

Unfunctionalized biaryl compounds were parallelly and combinatorially prepared by the traceless hydrogenolysis of biarylsulfonates supported on pentaerythritol. The hydrogenolysis using 2-propylmagnesium chloride in the presence of $dppfNiCl_2$ efficiently generated corresponding biaryl derivatives without any memory of the support. The strategy using pentaerythritol as a small soluble support was disclosed to have a potential to combine the benefits of both SPOS and solution-phase reaction with fast reaction rate, facile isolation of intermediates, easy analysis of intermediates and atom economical manner. The novel tetrapodal support is expected to be an efficient substitute for polymeric supports in many circumstances.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.3
• /
• pp.1055-1058
• /
• 2011

• 월간산업보건
• /
• s.267
• /
• pp.21-23
• /
• 2010

• Proceedings of the KAIS Fall Conference
• /
• 2004.06a
• /
• pp.311-314
• /
• 2004

Toxicity test fur various synthetic lubricant oil bases derived from biodiesel was carried out. The earthworms(Eisenia fetida) were maintanied in artificial soil consisting of sand for 14 days. Eisenia fetida was cultivated at temperature of $20{\pm}2^{\circ}C$, pH 6.0 $\pm$ 0.5 and moisture of $31\~37\%$. Pentaerythritol(PE) lubricant oil base was tested for acute toxicities to Eisenia fetida. The earthworms were exposed to each lubricant oil with various concentrations of lubricant oil base. After 14 days, the number of surviving earthworms and thier weight alteration during the test period was determined. $LC_{50}$(lethal concentration when $50\%$ of the population were killed) pentaerythritol was determined to be 1,555 mg/kg soil dry weight.