• Elastomers and Composites
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• v.18 no.1
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• pp.21-29
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• 1983

• Elastomers and Composites
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• v.7 no.2
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• pp.156-159
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• 1972

• Elastomers and Composites
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• v.6 no.2
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• pp.21-24
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• 1971

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1137-1141
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• 2007

This paper is concerned with the experimental research of magnetorheological elastomers (MREs). The modulus of the MR elastomers can be controlled by an applied magnet field, so that it can be effectively used for vibration suppression applications. The MR elastomer in this experiment is a mixture of KE-1300 silicone, carbonyl iron powder (300mesh) and a silicone hardener (CAT-1300). Three specimens were manufactured and tested by using the vibration testing instruments. The magnetic field was generated by the permanent magnets. The experimental results show that the natural frequencies of the test article with MR elastomer changes by the applied magnetic field. The performance of the MR elastomer can be increased by stronger magnetic fields. This is under investigation.

• Elastomers and Composites
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• v.51 no.4
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• pp.269-274
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• 2016

Two different reactive silicone oligomers, hydroxylpropyl terminated PDMS (PDMS-L) and 1-(2,3-dihydroxy-propoxy)propyl terminated PDMS (PDMS-B), were synthesized through hydrosilylation reaction under Karstedt's catalyst. Using the reactive silicone oligomers, two different silicone-modified gel-coat series were prepared to investigate their thermal and mechanical properties as well as surface characteristics according to reactive silicone oligomer contents. In case of thermal stabilities and mechanical properties, the gel-coat series containing PDMS-B showed higher values than that of the gel-coat series containing the PDMS-L. The contact angle for the gel-coat containing both silicone oligomers/was increased with reactive silicone oligomer contents but there was similar surface tension between PDMS-L and PDMS-B.

• Elastomers and Composites
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• v.50 no.3
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• pp.210-216
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• 2015

Polyurethane modified silicone (PUMS) was synthesized from various molecular weights of polydimethylsiloxane (PDMS 2000, PDMS 6000, PDMS 20000), polypropyleneglycol with molecular weight of 3000 g/mol (PPG 3000) and 2,4-toluenediisocyanate (TDI) under tin catalyst. Their structures were confirmed by the measurement of FT-IR and $^1H-NMR$, and the thermal properties were studied from DSC and TGA. Glass transition temperature of PUMS exhibited exothermic peak at $-63{\sim}-69^{\circ}C$, and residual weight was 19~35% at $800^{\circ}C$.

• Elastomers and Composites
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• v.44 no.3
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• pp.260-268
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• 2009

Modification of clay surface was attempted by treating the clay with bis[(3-triethoxysilylpropyl)tetra sulfide (TSS) to raise the hydrophobicity and to induce a chemical reaction between the clay and the high temperature vulcanization-type silicone rubber matrix with purpose of improving the compatibility between the components, and thereby Na-$MMTS_4$ and Fe-$MMTS_4$ were synthesized by treating Na-MMT and Fe-MMT with TSS, respectively. Silicone rubber/clay composites were prepared by compounding the clays with silicone rubber. Thermal stability and mechanical properties were evaluated as a function of the clay types and the surface modification.

• Elastomers and Composites
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• v.31 no.2
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• pp.111-121
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• 1996

The characteristic of silicone rubber can be seen from its resistance to both low and high temperature, whereas HNBR is resistant only in high temperature moderatly although it can be compounded to give good tensile properties, good oil resistance while silicone rubber severely lacks in these qualities. This study was initiated a balance of properties by blending HNBR and silicone rubber which is not considered for commercial blending; blends of HNBR with silicone rubber tend to show immiscible due to dissimilar nature of silicone and HNBR, the possibility of phase separation cannot be ruled out, in unfilled system after vulcanisation leading to premature failure. Attempt has been made to improve compatibility and minimise the layer seperation by the use of compatibilizer. Both filled and unfilled systems, in presence and absence of compatibilizer have been studied. Improvement in tensile properties of the blends or are observed as compared to the non-blended rubber. Different ratios of HNBR and silicone rubber are represented in this study. Blends of HNBR with silicone rubber were immiscible system. The tensile strength increased with filler loading.

• Elastomers and Composites
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• v.54 no.2
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• pp.142-148
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• 2019

In this study, the effects of filler particle size and shape on the physical properties of silicone rubber composites were investigated using inorganic fillers (Minusil 5, Celite 219, and Nyad 400) except silica, which was already present as a reinforcing filler of silicone rubber. Fillers with small particle sizes are known to facilitate the formation of the bound rubber by increasing the contact area with the polymer. However, in this experiment, the bound rubber content of Celite 219-added silicone composite was higher than that of Minusil 5-added silicone composite. This was attributed to the porous structure of Celite 219, which led to an increase in the internal surface area of the filler. When the inorganic fillers were added, both thermal decomposition temperature and thermal stability were improved. The bound rubber formed between the silicone rubber and inorganic filler affected the degree of crosslinking of the silicone composite. It is well-known that as the size of the reinforcing filler decreases, the reinforcing effect increases. However, in this experiment, the hardness of the composite material filled with Celite 219 was the highest compared to the other three composites. Furthermore, the highest value of 2.19 MPa was observed for 100% modulus, and the fracture elongation was the lowest at 469%. This was a result of excellent interaction between Celite 219 filler and silicone rubber.

• Elastomers and Composites
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• v.45 no.2
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• pp.106-111
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• 2010

Magneto-rheological elastomers (MREs) were manufactured by incorporation of magnetic responsible powder (MRP) into natural rubber and silicone rubber. The optimum loading amounts of MRP was 30 vol.% and the natural rubber based MRE (NR-MRE) showed better mechanical property than that of silicone rubber based MRE (S-MRE). However, the modulus shift ratio caused by S-MRE, measured by Self-modified Electromagnet Applied Fast Fourier Transform Analyser (SEFFTA), was higher than that of NR-MRE. The modulus shift ratio caused by NR-MRE was 10%, while the modulus shift ratio caused by S-MRE was 35.7%. The modulus shift ratio could be improved by orienting the magnetic direction of MRP before crosslinking the MRE. The degree of orientation of MRP was analyzed using SEM.