A. M. Motawie

Coatings from epoxidized (polyurethane‐polyester) resin system

Epoxidized polyurethane was synthesized from the reaction of the prepared epoxidized linseed oil with toluene diisocyanate (TDI) at a NCO-to-OH ratio equal to 5. The prepared epoxidized linseed oil was also reacted with phthalic anhydride at a molar ratio of 1 : 4 to give epoxidized polyester. Epoxidized polyurethane and epoxidized polyester were mixed in different weight ratio percentages to give three types of epoxidized (polyurethane-polyester) resin systems. These resin systems were tested physically and chemically and evaluated as coatings for both metal and glass panels. The data obtained indicate an exceptional combination of properties, such as adhesion, bending, and chemical resistance of the epoxidized (polyurethane-polyester) resin system of the weight ratio percentage of 15 : 85. Thus, these materials can be recommended to be used as coating materials.

Adhesives and coatings based on poly(vinyl acetal)s

Phenolic resins such as resole phenol- and cresol-formaldehyde, as well as low-molecular-weight epoxy resin based on bis(4-hydroxy phenol) cyclohexane were prepared and modified with various types of the prepared poly(vinyl acetal)s. Poly(vinyl formal), poly(vinyl isobutyral), and poly(vinyl propional) were used. This study indicated that the optimum conditions for curing phenolic or epoxy resin-poly(vinyl acetal)s adhesive compositions are of an equal weight ratio or a 2: 1 weight ratio in the presence of phthalic anhydride (10 or 20 wt %) of resin content as a curing agent at 150°C for 20 or 60 min, respectively. The effect of acetal type on the tensile shear strength values of resin samples, cured under the previously mentioned optimum conditions for different times, was investigated. The effect of structure of cresol-formaldehyde and epoxy resins was also studied. Metallic and glass coatings from the previous pure resins and their formulated mixtures were also prepared and evaluated as varnishes or paints.

Some fatty esters as plasticizers and fungicides for natural rubber

The prepared n-fatty alcohols from petroleum sources are esterified with a dibasic acid series (malonic, succinic, glutaric and adipic) or phthalic anhydride, giving the corresponding C12 fatty esters. The prepared C12 fatty esters were formulated with natural rubber. The drying time, some mechanical properties and fungitoxicity of the prepared film samples were examined. The conventional dibutyl phthalate plasticizer was used for the purpose of comparison. The data obtained indicate that the prepared fatty esters can be used as plasticizers with antifungal activity for natural rubber. ©1997 SCI