New organosoluble poly(arylene ether nitrile) copolymers based on 9, 9-bis(3, 5-dimethyl-4-hydroxyphenyl)xanthene. (September 2016) - Yang, Qiu-Fen
Several poly(arylene ether nitrile) (PAEN) copolymers containing multi-methyl and cardo xanthene groups were synthesized by nucleophilic substitution reaction of 2, 6-difluorobenzonitrile with varying molar ratios of 9, 9-bis(3, 5-dimethyl-4-hydroxyphenyl)xanthene (BDMHPX) and hydroquinone (HQ) (80/20–40/60) in N -methyl-2-pyrrolidone (NMP) in the presence of anhydrous potassium carbonate. These new PAENs had inherent viscosities between 0.56 and 0.68 dL g –1, and their weight-average molecular weights and number-average molecular weights were in the range of 33, 300–36, 500 g mol −1 and 17, 300–18, 400 g mol −1, respectively. All polymers were amorphous and soluble in dipolar aprotic solvents such as NMP and N, N -dimethylacetamide and even in THF and chloroform at room temperature. These PAENs showed glass transition temperatures ( T g s) between 248°C and 289°C, and the T g values were found to increase with increase of the BDMHPX content in the polymeric main. Thermogravimetric analysis showed that all PAENs were stable up to 400°C, with 5% weight loss temperatures ranging from 427°C to 448°C and char yields of 57–61% at 700°C under nitrogen atmosphere. All new PAENs could be cast into strong and flexible films with a tensile strength of 93–115 MPa, elongation at break of 10–12%, and tensile modulus of 3.3–3.5 GPa.