5226
Doaa Samir Abd El-Rehim Mahmoud
Evaluation and characterization of rubber composites loaded with cation exchange clay and cationic surfactant
Rubber, fillers, clay, cations exchange, surfactant, rubber composites
Inclusion of filler polymer matrix creates new materials such as polymer composites, which show improved physical, mechanical, thermal properties, etc. Nowadays, clays are the most studied fillers because they are easily available in nature and cheap. Clay is classified as a hydrophilic material, which is incompatible with most organophilic polymers. Therefore, clay can be modified before being used as filler via the substitution of the inorganic interlayer cations with organic surfactant and/ or inorganic cations (single and double). The preparation of modified bentonite takes place using cetyl-trimethyl ammonium bromide (CTAB) at different concentrations, then these organobentonite (OB) were dispersed in host polymer. The native or naturally occurring Na+ ions in bentonite and zeolite were replaced by single (Mg, Zn and Sr) and double cations (Zn-Mg, Mg-Sr and Zn-Sr) to give cations exchange bentonites (CEBs) and cations exchange zeolites (CEZe). However, it was scarcely utilized in the rubber industry because these OB affords many advantages, such as ease of preparation, relative cheapness, and being considered as environmentally friendly. The OB, CEBs and CEZe have been evaluated as efficient reinforcing filler in nitrile-butadiene rubber (NBR) and styrene-butadiene rubber (SBR) matrices. The major areas of SBR and NBR consumption are in tire industry, automotive industry and in the production of technical parts, cable insulation materials, shoes soles, hoses, etc.The objective of this work was to study the effect of modified clay on the thermal and physico-mechanical properties of the rubber composites. The degree of dispersion or diffusion of the modified clay in the rubber composites was investigated using scanning electron microscopy (SEM). Rubber (NBR or SBR) loaded with 0.5CEC organoclay showed the best rheometeric and physico-mechanical properties among the prepared rubber/OB composites. Mg-bentonite (single cations), Mg-Zn-bentonite (double cations) and their modified ones showed the highest properties among the other NBR and SBR composites loaded with the different cations. Sr-zeolite showed the highest properties in NBR, and Mg-zeolite showed the highest properties in SBR, while Mg-Zn-zeolite showed the best properties in both matrices.
2016
M.Sc
Cairo
Science