• Elastomers and Composites
• /
• v.37 no.4
• /
• pp.217-223
• /
• 2002

Silica-filled rubber compounds show poor filler dispersion and slow cure characteristics compared to carbon black-filled ones. In general, a silica-filled rubber compound contains silane coupling agent (bis-(3-(triethoxysilyl)-propyl)-tetrasulfide, TESPT) and diphenylguanidine (DPG) to improve the filler dispersion and to make fast cure characteristics. Acrylonitrile-butadiene rubber (NBR) improves the filler dispersion in silica-filled styrene-butadiene rubber (SBR) compounds. In this study, effect of NBR on the properties of silica-filled SBR compounds was investigated. Properties of the compounds which contain NBR without DPG or with small amount of TESPT (Compound A) were compared with those of the compounds which contain TESPT and DPG without NBR (Compound B). Scorch time of Compound A is faster than those of Compound B. Modulus and tensile strength of Comound A are slightly lower than those of Compound B. Traction property of the Comound A is better than that of the Compound B. Addition of NBR leads to reduction of the used amount of TESPT and DPG.

• Polymer(Korea)
• /
• v.24 no.2
• /
• pp.220-227
• /
• 2000

Silica and carbon black filled natural rubber (NR) vulcanizates were prepared with different mixing modes and amounts of fillers. Curing characteristics, morphology. and tear properties of the NR vulcanizates were investigated. The NR vulcanizates filled with silica and carbon black sequentially showed longer induction time ($t_2$), cure index ($t_{90}$ ), and lower maximum torque ($T_{max}$ ) than the NR vulcanizates filled with them simultaneously, during curing process. The former showed superior dispersion of fillers and tear properties to the latter. The NR vulcanizates containing 30 phr of silica showed excellent properties in the experimental range.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1994.04a
• /
• pp.215-220
• /
• 1994

본 연구의 목적은 당사 콘크리트 배합설계 프로그램인 쌍용배합설계시스템(Ssangyong Mix Proportioning Design System ; 이하 SMPD라 칭한다)을 기본으로해서 슬래그시멘트에 대한 콘크리트 배합설계(안)을 제안함으로써 콘크리트 현장에서 합리적으로 콘크리트를 제조할 수 있도록 하는데 있다. 연구 내용은 슬래그시멘트와 보통시멘트간의 콘크리트 물성차이를 실험실적으로 규명하기 위해서 슬래그 함유량 및 양생 온도별로 슬래그시멘트의 콘크리트 강도발현특성, 물시멘트비, 단위수량변화 및 응결특성 등을 검토하였으며 그 결과를 이용하여 슬래그시멘트의 콘크리트 배합설계를 시행, 표준배합과 현장배합표를 제시하였다.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.949-952
• /
• 2008

The latex modified concrete(LMC) was adds latex in the plain concrete as the latex has increase the durability of concrete. But it is added in LMC manufacture, which is a high price compares with different material and there is a weak point where the construction expense is very high. So, this study are decided mix proportion from the scope where the security strong point of LMC is possible and reduced the material expense by control the latex contents. and these mix proportions are estimated the chloride ion diffusion. The results of study appear that it can reduced the latex content until the $5{\sim}10$% of cements, and these mixtures are very low chloride ion diffusion.

• The tire
• /
• s.81
• /
• pp.2-12
• /
• 1979

요지:특수하게 처리한 Cellulose Fiber를 고무에 배합함으로써 배합고무의 기계적 성질을 향상시킬 수 있다. 즉, 소량의 Cellulose Fiber를 천연고무 또는 합성고무에 배합하여 배합고무의 내절상(Cut)성장, 내 Chipping성을 향상시킬 수 있다.

• Elastomers and Composites
• /
• v.40 no.1
• /
• pp.29-36
• /
• 2005

Mixing condition and procedure affect properties or a filled rubber compound such as filler dispersion, viscosity, and bound rubber formation. Influence of separate load of styrene-butadiene rubber (SBR) and acrylonitrile-butadiene rubber (NBR) on properties or silica-filled SBR compounds containing NBR was studied. Cure time and cure rate became faster as NBR content increased. The crosslink density increased with increase in the NBR content. The bound rubber content also increased as the NBR content increased. NBR content of the bound rubber was higher than that of the compounded rubber. The bound rubber content was higher when SBR and NBR were loaded separately than when loading simultaneously. The cure time and cure rate were slower for the separate load than for the simultaneous one. The crosslink density was also lower for the former case than for the latter one.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 2006.05a
• /
• pp.86-89
• /
• 2006

본 연구는 돈육의 비인기 부위를 기준으로 하고, 우육을 일부 배합하여 관능적 특성을 살린 돈육과 우육의 적절한 배합비를 결정하여 재구성 반건조 육포를 제조하여 품질 특성을 조사하는 데에 있다. 전체적으로 배합비에 상관없이 케이싱으로 충전 후 제조한 재구성 반건조 육포중 셀룰로오즈로 제조한 재구성 육포가 건조가 잘 이루어져 수분 함량($32{\sim}36%$)과 수분활성도($0.83{\sim}0.85$)가 가장 낮아 전단력이나 metmyoglobin 함량이 높았으나 관능 평가에서 대체로 좋은 평가를 받아 재구성 반건조 육포 제조에 가장 알맞은 성형틀로 선택하였다. 또한 원하고자 하는 결착력이 좋고 조직감이 개선된 재구성 반건조 육포의 배합비에 있어서 T-3 배합비인 돈육과 우육의 비율이 90:10 이며, 결합육으로서 돈육과 우육이 5:5의 비율을 유지하였을 때, 이화학적 특성 및 관능적 특성에 있어서 재구성 반건조 육포로서 가장 좋은 평가를 받았다.

• 한국도로학회지:도로
• /
• v.11 no.4
• /
• pp.37-44
• /
• 2009

• Elastomers and Composites
• /
• v.37 no.1
• /
• pp.14-20
• /
• 2002

Silica-filled rubber compound needs longer mixing time compared to carbon black-filled one since it has poor dispersion or the filler. Influence of the mixing procedure on the properties of natural rubber compound filled with both silica and carbon black was studied. The discharge temperature of the master batch (MB) mixing was $150^{\circ}C$. The mixing time was longer when silica and carbon black were loaded separately than when loaded simultaneously. The mixing time was longer when silica was loaded first than when carbon black is loaded first. The compounds prepared by one MB step (conventional mixing) were compared with the compounds prepared by two MB steps (two-step mixing). Scorch times of the two-step mixing compounds were longer than those by the conventional mixing ones. Bound rubber contents of the formers were lower than those of the tatters. The two-step mixing vulcanizates had longer elongation at break, higher tensile strength, and better fatigue life.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.10 no.5
• /
• pp.106-114
• /
• 2006

This paper investigates the fundamental properties and shrinkage characteristics of low shrinkage high performance concrete(LSHPC), using mock-up specimens. According to the test results, the most suitable mix proportions of LSHPC need a higher dosage of SP agent and AE agent, in order to obtain the target of slump flow and air content. This is due to reduce fluidity and air content respectively. It also presented earlier setting time than control concrete by 6 hours and exhibited compressive strength of 60MPa at age 28 days. Autogenous shrinkage of LSHPC was the half of the value of control concrete. Drying shrinkage of center section of LSHPC showed similar tendency with autogenous shrinkage, because of no internal moisture movement, while surface section had larger drying shrinkage. The specimen with embedded reinforcing bar had smaller deformation owing to confinement of reinforcing bar.