The benzoxazines of three naturally occurring phenylpropanoid phenols: ferulic, coumaric, and phloretic acids, and their esters are described. Benzoxazines with conjugated unsaturated chains exhibit unusual poor thermal stability and degrade partially at the polymerization temperature making necessary the use of a catalyst (BF 3 .Et 2 O) to low the polymerization temperature and prevent degradation. Polybenzoxazines are prepared thermally and characterized by DSC and TGA techniques.The resulting materials have superior Tgs when compared with those prepared from an unsubstituted monofuctional benzoxazine due to the additional crosslinking through the ester and carboxylic moieties. V C 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 00, 000-000 KEYWORDS: cationic polymerization; crosslinking; polybenzoxazines; renewable resources; thermal properties; thermosets INTRODUCTION Polybenzoxazines are a relatively new class of phenolic type thermosets developed to overcome most of the short-comings associated with the traditional phenolic resins. During the last decade, polybenzoxazines have attracted significant attention of both industry and research community because of their unique advantages over most of the known polymers, 1 becoming one of a rare few new polymers commercialized in the past 30 years.
Fluorination is a common strategy for improving the electronic properties of π-conjugated materials, and this has shown to be important for applications in organic electronics, especially for the fabrication of...
Benzothiadiazole (BT) and its derivatives have been widely used as strong acceptors for enhancing π-stacking and improving the charge carrier transport properties in optoelectronic applications.
Ring‐opening metathesis polymerization (ROMP)‐derived poly(oxanorbornene imide)s bearing bay‐linked mono‐alkoxy‐M1 and 1,7‐di‐alkoxy M2 functionalized perylene diimides (PDIs) were synthesized using Grubb's third (G3) and Hoveyda‐Grubbs second generation (HG2) ruthenium‐alkylidene metathesis initiators. The mono‐alkoxy‐derived PDI‐based non‐ladderphane polymer polyM1 displayed 67% to 77% of the trans olefin content in the polymer chain depending on the initiator used for the polymerization. When using the symmetrical 1,7‐di‐alkoxy‐derived PDI‐based polymer polyM2 having the ladderphane type‐structure, this displayed a significant amount of cis and trans olefin contents in the polymer chains, irrespective of the type of initiators used for the polymerization. ROMP of both monomers M1 and M2 proceeded in a well‐controlled manner with a linear dependence of molecular weight on the monomer/initiator ratio using G3 as initiator. Optical properties of the ladderphane‐based polyM2 and non‐ladderphane‐based polyM1 were characterized in both solution and the film state. X‐ray diffraction (XRD) analysis for all the polymers showed significant π‐stacking in the thin film state with ordered molecular packing and closer values of d‐spacing for both polyM1 and polyM2. Film morphology examined by AFM elucidated homogenous smooth polymer surface for both polymers in general, but with some irregularities observed for polyM1. In addition, CV analysis revealed both polymers could be good candidates as electron‐accepting materials, with excellent film‐forming ability, and thermal stability.
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