Design and Effects of the Cinnamic Acids Chemical Structures as Organocatalyst on the Polymerization of Benzoxazines

Abstract

<jats:p>This study focuses on the catalytic effect of the two geometric isomers of a cinnamic acid derivative, E and Z-forms of 3-methoxycinnamic acid (3OMeCA), analyzing the influence of their chemical structures. E and Z-3OMeCA isomers show very good catalytic effect in the polymerization of benzoxazines, decreasing by 40 and 55 °C, respectively, the polymerization temperatures, for catalyst contents of up to 10% w/w. Isothermal polymerizations show that polymerizations are easily realized and analyzed at temperatures as low as 130 °C and at much shorter times using Z-3OMeCA instead of E-3OMeCA. Thus, both cinnamic acids are good catalysts, with Z-3OMeCA being better. The molecular reasons for this difference and mechanistic implications in benzoxazine polymerizations are also presented.</jats:p>

Review on the Accelerated and Low-Temperature Polymerization of Benzoxazine Resins: Addition Polymerizable Sustainable Polymers

“…To reduce the carbon foot print, exploration of non-petrochemical feedstocks that are obtained naturally or in bio-wastes is actively sought both as solvent or solvent-free reactions [ 84 ]. These include cardanol (C) [ 85 , 86 , 87 , 88 , 89 , 90 ]; guaiacol (G) [ 89 , 91 , 92 ]; eugenol [ 93 , 94 ]; isoeugenol [ 95 ]; vanillin (V) [ 96 , 97 , 98 ]; umbelliferone (U) [ 99 ]; catechol [ 100 ]; cinnamic, ferulic, coumaric [ 101 , 102 ] and phloretic acid [ 101 , 103 , 104 ]; magnolol [ 105 ]; resveratrol [ 106 ]; humic acid (coal origin) [ 107 ]; daidzein [ 108 ]; naringenin [ 109 ]; arbutin-linked phenol [ 110 ]; levulinic acid based diphenolic acid [ 111 , 112 ]; sesamol [ 113 ]; apigenin [ 84 ] and amines such as stearylamine [ 93 ], dopamine [ 114 ], furfuryl amine (fa) [ 95 , 115 ], aminolysed poly(ethylene terephthalate) [ 116 ] and isomannide diamine (ima) [ 89 ], as shown in Figure 3 .…”

“…Natural renewable phenolic acids, cinnamic [ 102 ], ferulic [ 101 ], coumaric [ 101 ] and phloretic acids [ 104 ] besides their utility as a feedstock for the synthesis of benzoxazine monomer, were also used as catalyst to reduce the polymerization temperature of the polymerization reaction.…”

Understanding the Stereochemical Effect on the Properties of Emerging Thermosets: Sustainable Polybenzoxazines

“…In terms of sustainability, a wide variety of phenolic feedstock is easily accessible as such or can be derived from naturally abundant available alternative resources. This includes cardanol (C); − guaiacol (G); ,, eugenol; , isoeugenol; vanillin (V); , umbelliferone (U); catechol; cinnamic, ferulic, coumaric, , and phloretic acid; ,, magnolol; resveratrol; daidzein; naringenin; and bio-/waste-sourced modified amines such as stearylamine, dopamine, furfuryl amine (fa), , and aminolyzed poly­(ethylene terephthalate), which are explored in PBz chemistry . Most recently, the utility of isomannide diamine (ima) to form a BPA-free bisbenzoxazine monomer has been reported .…”