Fly ash (FA)/general purpose unsaturated polyester resin (GPR) particulate composites were made. The effect of the surface treatment of FA with two different silane coupling agents (CAs) on the mechanical properties, such as the tensile, flexural, compressive, and impact strengths and hardness, of FA-GPR composites were studied. The properties of FA-CA-GPR were also compared with that of GPR and CaCO 3 -GPR. An enhancement in the tensile, flexural, compressive, and impact strengths and a decrease in the tensile and flexural moduli were observed when FA was surface treated with CA. Hardness also increases with CA-treated FA.

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ABSTRACT:The polymer systems of vinyl latex, epoxy latex/resin, and phenol formaldehyde were used to modify sand-cement mortar at room temperature. The compressive strength increased with an increase of the latex/resin concentration, with the addition of CaCl 2 or CaCO 3 , and with the addition of superplasticizer. Tensile and flexural strengths also increased with polymer incorporation. The porosity of the modified mortar decreased with the addition of resin. The percentage of water absorption and acid solubility were found to decrease for the latex/resin modified samples.

A number of TiCl4 catalysts supported on MgCl2 which was activated by the recrystallization method using different alcohols were prepared with ethyl benzoate or dibutyl phthalate as the internal electron donor. All the catalysts were characterized by BET, x‐ray diffraction, and hydrolysis–GC analysis. Kinetics of polymerization of 1‐octene was studied with three of the above catalysts (having different internal electron donors) activated by AlEt3. The rate of polymerization increased linearly with increasing temperature, and catalyst and monomer concentrations. From the Arrhenius plot, the overall activation energies of polymerization were determined and the dependence of rate on the AlEt3 concentration could be explained by the Langmuir‐Hinshelwood mechanism. 13C‐NMR was used to study the effect of internal electron donors on the % isotacticity of poly(1‐octene). The catalytic activities of all the catalysts were compared in 1‐octene polymerization. © 1994 John Wiley & Sons, Inc.

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