The phenylnitrile functional benzoxazine monomers, 3‐phenyl‐3,4‐dihydro‐ 6‐nitril‐2H‐1,3‐benzoxazine (NBen‐a) and 4,4′‐bis(3,4‐dihydro‐6‐nitril‐2H‐1,3‐benzoxazine‐3‐yl)phenylether (NBen‐De), were synthesized and characterized by Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (1H‐NMR). The curing behaviors of NBen‐a and NBen‐De were characterized by differential scanning calorimetry (DSC) and FTIR. Thermal stability and dynamic mechanical properties of the cured NBen‐a and NBen‐De were investigated using thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The cured NBen‐a and NBen‐De showed glass transition temperature (Tg), the thermal stability improved as compared to the analogous polybenzoxazine without phenylnitrile group. Copyright © 2008 John Wiley & Sons, Ltd.

Xylok polybenzoxazine with acetylene group terminals (XPBZAs) were synthesized by the Mannich-like condensation of Xylok prepolymer, formaldehyde, aminophenylacetylene, and aniline, and their structures were characterized by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ( 1 H NMR). The curing behavior of XPBZAs was determined by differential scanning calorimetry and FTIR. Thermal behavior and dynamic mechanical properties of the cured XPBZAs were investigated using thermogravimetric analysis and dynamic mechanical analysis. The results showed glass transition temperature (T g ), the thermal stability, and anaerobic char residue of cured XPBZAs increased as the content of acetylene groups increased. EXPERIMENTALMaterials p-Xylyleneglycoldimethylether (99%) was purchased from Shouguang Jinzeyang Chemical (China). Chloroform, phenol, formaldehyde, aniline, and stannic chloride were purchased from Sinopharm Chemical Reagent. m-Amino-phenylacetylene (99%) was prepared and supplied by the fine-chemical laboratory in our university [22]. Synthesis of Xylok PrepolymerXylok prepolymer was synthesized from p-xylyleneglycoldimethylether and phenol using stannic chloride as a catalyst [11]. A mixture of 117.5 g (1.25 mol) of phenol and 83 g (0.5 mol) of p-xylyleneglycoldimethylether were

Benzoxazine precursors (BOZP), 6,6′‐bis(2,3‐dihydro‐3‐(3‐ethynylphenyl)‐4H‐1,3‐ benzoxazinyl)ketone and 6,6′‐bis(2,3‐dihydro‐3‐(3‐ethynylphenyl)‐4H‐1,3‐benzoxazinyl)ether were synthesized and characterized by Proton nuclear magnetic resonace (1H‐NMR) and Fourier transform infrared spectroscopy (FTIR). The polyarylacetylene (PAA) was synthesized through thermal polymerization of diethynylbenzene, and characterized by 1H‐NMR, FTIR, and Differential Scanning Calorimetry (DSC). The BOZP/PAA blends were prepared with different contents of PAA, and their viscosity was measured using NDJ‐79 rotating visometer. The curing behavior of BOZP/PAA blends was characterized by DSC. The thermal stability of cured BOZP/PAA blends was studied using Thermogravimetric Analysis, the results show char yield at 800°C was in the range of 78–84%. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Subsequent melting behavior after isothermal crystallization at different temperatures from the isotropic melt and nonisothermal crystallization kinetics and morphology of partially melting sPB were carried out by differential scanning calorimetry (DSC), polarized light microscopy (POM), respectively. Triple melting-endothermic peaks were observed for the polymer first isothermally crystallized at temperatures ranging from 141 to 149°C, respectively, and then followed by cooling at 10°C/min to 70°C. Comparing with the nonisothermal crystallization from the isotropic melt, the nonisothermal crystallization for the partially melting sPB characterized the increased onset crystallization temperature, and the sizes of spherulites became smaller and more uniform. The Tobin, Avrami, Ozawa, and the combination of Avrami and Ozawa equations were applied to describe the kinetics of the nonisothermal process. Both of the Tobin and the Avrami crystallization rate parameters (K T and K A , respectively) were found to increase with increase in the cooling rate. The parameter F(T) for the combination of Avrami and Ozawa equations increases with increasing relative crystallinity. The Ziabicki's kinetic crytallizability index G Z for the partially melting sPB was found to be 3.14. The effective energy barrier ⌬⌭ describing the nonisothermal crystallization of partially melting sPB was evaluated by the differential isoconversional method of Friedman and was found to increase with an increase in the relative crystallinity. At the same time, Hoffman-Lauritzen parameters (U and K g ) are evaluated and analyzed from the nonisothermal crystallization data by the combination of isoconversional approach and HoffmanLauritzen theory. The K g value obtained from DSC technique was found to be in good agreement with that obtained from POM technique.