No abstract

No abstract

No abstract

A kind of novel n ¼ 2 phthalonitrile oligomer containing biphenyl ethernitrile (2PEN-BPh) had been firstly synthesized from 2,6-dichlorobenzonitrile, 4,4 0 -biphenol and 4-nitrophthalonitrile via solution reaction, and the 2PEN-BPh was characterized by FTIR, 1 H-NMR spectra which exhibited that cyano groups and ethernitrile linkages existed in the backbone of 2PEN-BPh. The 2PEN-BPh oligomer was blended with bisphthalonitrile monomer, the curing reaction behaviors of the blends were studied by FTIR, DSC, and rheological analysis. The thermal and thermo-oxidative stabilities of the 2PEN-BPh/BPh polymers were investigated by TGA, and the results showed that the completely cured polymers could achieve char yields up to 78% at 800 C in nitrogen, above 11% at 800 C in air. The whole research indicated that the 2PEN-BPh/BPh blends could efficiently improve the processability of BPh monomer without scarifying other desirable high temperature properties.

Poly(arylene ether nitrile) (PEN) endcapped with phthalonitrile (PEN-n) was synthesized by incorporating phthalonitrile into the terminals of PEN. The as-prepared flexible PEN-n (after elevated temperature treatment) was characterized by infrared spectroscopy, nuclear magnetic resonance, gel permeation chromatography, and rheological measurements. In addition, the effects of curing behaviors on properties of PEN-n films were studied by thermal, dielectric and mechanical measurements. Differential scanning calorimetry analysis showed that glass transition temperature of PEN-n was improved from 176 to 232 C as the curing temperature and time increased. Thermal gravimetric analysis revealed that initial decomposition temperature of PEN-n cured at 320 C for 2 h was 570 C. Mechanical properties showed that tensile strength of PEN-n uncured and cured at 320 C for 3 h was 85 and 97 MPa, respectively. The dielectric properties showed that the dielectric constant of PEN-n film decreased from 4.0 to 3.1 as the curing time increased and dielectric loss of PEN-n was 0.01 at 100 kHz. This kind of PEN-n film may be used as a good candidate for high-performance polymeric materials. V C 2012 Wiley Periodicals, Inc. J Appl Polym Sci 125: [3829][3830][3831][3832][3833][3834][3835] 2012