Synthesis and Characterization of Schiff Bases Derived from 3-(4-methoxyphenyl) Acrylic Acid and 3-(Benzo[d][1,3]dioxol-5-yl) Acrylic Acid

Two kind of Schiff bases (A1-A3) and (B1-B3) containing a benzothiazole moiety have been synthesized, description by (FT-IR and 1HNMR, 13CNMR) and used as photo stabilizers for poly (styrene-co-butadiene) at low concentrations. The first type (A1-A3) was created by reacting 4-methoxy cinnamic acid with thionylchloride to produce 3-Chloro-1-benzothiophene-2-carbonyl-chloride and after that, it was reacted with hydrazine to give 3-chloro-6-methoxybenzo[b]thiophene-2-carbohydrazide (A). In contrast, the Schiff bases compounds (B1-B3) were synthesized by reacting 3,4-(methyenedioxy) cinnamic acid with thionyl chloride to produce 7-chlorothieno [2',3':4,5]benzo[1,2- d][1,3]dioxole-6carbonyl chloride, and then it was reacted with hydrazine to produce 7-chlorothieno[2',3':4,5]benzo[1,2-d][1,3]dioxole-6-carbohydrazide (B). Several methods were used to evaluate the effectiveness of Schiff bases as photo stabilizers on poly (styrene-co-butadiene). For instance, the changes in infrared and ultraviolet spectra, chain scission, molecular weight, and quantum yield upon exposure to the UV light were observed. All of the additives applied significantly slowed down photo-degradation of poly (styrene-co-butadiene).