Synthesis and properties of sulfonated polyarylene ether nitrile copolymers for PEM with high thermal stability

Synthesis and characterization of sulfonated poly(eugenol-co-allyleugenol) membranes for proton exchange membrane fuel cells

The research of sulfonated eugenol-allyleugenol copolymer (SPEAE) based membrane for fuel cell from eugenol derivate had been conducted. First, eugenol was reacted with various weights of allyl eugenol to form eugenol-allyleugenol copolymer (PEAE). Determination of the optimum composition of PEAE was done by testing the swelling properties. Then, PEAE was sulfonated using concentrated sulfuric acid with time variations of 1, 2, 3, 4, and 5 h to form SPEAE. The SPEAE produced was tested for the degree of sulfonation, water uptake, cation exchange capacity, and membrane proton conductivity. In addition, the characteristics of the PEAE and SPEAE copolymer membranes were also analyzed using FTIR spectrophotometers, 1H-NMR, TGA, and DSC. The results showed that the copolymerization of eugenol:allyleugenol (EG:AEG) with a ratio of 10:1 gave the lowest swelling degree. The best SPEAE copolymer was obtained from sulfonation for 2 h with yield, degree of sulfonation, water absorption value, proton conductivity, and cation exchange capacity of 90.6%, 12.87%, 50.7%, 1.83 × 10^-5 S cm^-1 and 0.356 meq/g, respectively. FTIR analysis shows the formation of PEAE with the loss of the vinyl eugenol groups used to form the polymer and shows the formation of SPEAE in the presence of sulfonate groups from the sulfonation reaction. ¹H-NMR also confirmed the presence of the PEAE and SPEAE copolymers. In addition, analysis of thermal properties with TGA and DSC also showed that sulfonate treatment could improve membrane stability.

Synthesis of novel poly(arylene ether amide) containing aliphatic ring for optical property

In this work, the monomer N, N′-bis(4-fluorobenzamide)dicyclohexyl methane (BFDCM) was synthesized successfully by 4-fluorobenzoylchloride and 4,4′-diaminodicyclohexylmethane through interfacial reaction, and then the monomer BFDCM and 1,4-benzenediol (HQ) or 4.4′-biphenol (BH) were used to prepare the novel poly(arylene ether amide) (HQ-BFDCM and BH-BFDCM) containing an aliphatic ring in the main chain by nucleophilic substitution in NMP solution. These two polymers exhibited the inherent viscosities ranging from 0.828 to 1.044 dL g−1, high glass-transition temperatures (Tg) of 214.1–235.0 °C, and weight-loss temperature (T5%) of 425.2–441.3 °C. The polymers HQ-BFDCM and BH-BFDCM could completely or partly dissolve in some polar solutions, such as NMP, DMF, and so on, and they showed moderate corrosion resistance. Additionally, the obtained polymers HQ-BFDCM and BH-BFDCM exhibited good optical property, and the optical transmittances of HQ-BFDCM and BH-BFDCM were 74% and 80% at 450 nm, respectively, which showed that they could be applied to the heat-resistant optical films.

Novel poly(arylene ether nitrile) containing pendant aliphtatic ring in the chain: Synthesis and properties

Two kinds of novel poly(arylene ether nitrile)s (CPDP-DCBN and CHDP-DCBN) containing pendant aliphtatic ring were synthesized by 4,4′-cyclopentane-1,1′-diyldiphenol (CPDP) or 4,4′-cyclohexane-1,1′-diyldiphenol (CHDP) and 2,6-dichlorobenzonitrile (DCBN) in this work. The inherent viscosities of poly(arylene ether nitrile)s (PENs) were in the range of 0.701–0.806 dL g−1. The polymers showed high glass transition temperatures ( T g) of 185.4–196.4°C and weight-loss temperatures ( T5%) of 447.8–454.3°C. The obtained CPDP-DCBN and CHDP-DCBN could be hot pressed into the films, which showed the tensile strengths of 82.6 MPa and 86.8 MPa, respectively. And the storage modulus of CPDP-DCBN and CHDP-DCBN were about 1.0 GPa and 1.5 GPa at 150°C, respectively. Additionally, the PENs could be dissolved in many solutions at room temperature, such as NMP and concentrated H2SO4, indicating that they had good solubility; they can be processed by the solution method. Meanwhile, the optical transmittance of CPDP-DCBN was 78.1% at 450 nm; it has potential to be applied to the heat-resistant optical film.

Sulfonated carbon nanotubes synergistically enhanced the proton conductivity of sulfonated polyarylene ether nitriles

The effect of sulfonated carbon nanotubes using an acyl chloride method on proton conductivity of sulfonated polyarylene ether nitriles was investigated.