Effect of a direct sulfonation reaction on the functional properties of thermally-crosslinked electrospun polybenzoxazine (PBz) nanofibers

Abstract

Functionalization of PBz by electrospinning of nanofibers then thermal crosslinking followed by direct sulfonation process.

Self‐doped sulfonated polyaniline ultrafiltration membranes with enhanced chlorine resistance and antifouling properties

“…The introduction of sulfonic acid groups (SO 3 H) into the aromatic polymers shows significant improvement in chemical and physical properties 44–46 . The incorporation of SO 3 H groups into the polymer chain may alter membrane properties such as ion‐exchange capacity, hydrophilicity, solubility in polar solvents, and electroactivity over a broad range of pH 47 .…”

State‐of‐the‐Art of the Synthesis and Applications of Sulfonated Carbon‐Based Catalysts for Biodiesel Production: a Review

“…After undergoing the sulfonation process for 24 h, few broken randomly oriented continuous, interconnected fiber networks were observed in the electrospun nanofibers as reported by Parreño et al [ 98 ] Because the previous study has deduced that a high acid concentration of >0.2 mol L −1 will cause the membrane samples to become more brittle, therefore it can be evidenced that the concentration of SO 3 H groups in the samples is directly proportional to the reaction time to promote a higher degree of sulfonation. [ 98 ] Generally, the higher the sulfonation time, the longer is the contact time between SO 3 H groups with the catalysts and the greater the intensity and density of the acid sites. Thus, highly active catalyst surface sites are very promising for the efficient catalytic performance.…”

“…The optimum sulfonation process periods for SCC produced from glucose-starch and corn straw mixture were determined to be at 4 and 5 h, respectively. [100] After undergoing the sulfonation process for 24 h, few broken randomly oriented continuous, interconnected fiber networks were observed in the electrospun nanofibers as reported by Parreño et al [98] Because the previous study has deduced that a high acid concentration of >0.2 mol L À1 will cause the membrane samples to become more brittle, therefore it can be evidenced that the concentration of ─SO 3 H groups in the Figure 7. Schematic diagram of the consecutive carbonization-sulfonation synthesis of magnetic biochar acid catalyst.…”

“…Beyond the optimal point, any further increase in the sulfonation time will not bring any positive impact to the overall acid density values. The statement is made based on the experimental investigations conducted by Gong et al [ 95 ] and Parreno Jr et al, [ 98 ] where the density of SO 3 H groups in the catalysts increased slightly when the sulfonation time increased from initial point up to the optimum point, but no further improvement can be observed beyond the optimum point. Kucera and Jancer also stated that sulfonation and desulfonation are reversible reactions that are influenced by both the sulfonating temperature and time, with higher temperatures and longer times favoring desulfonation.…”

Highly Proton-Conducting Membranes Based on Poly(arylene ether)s with Densely Sulfonated and Partially Fluorinated Multiphenyl for Fuel Cell Applications

“…After the sulfonation treatment, a broad absorption band was generated from 3749 to 2425 cm −1 (–OH stretching) and was accompanied by changes in the absorption peaks in fingerprint regions, as shown in Figure S15a,b , which reveals a slight shift of the peak corresponding to symmetrical stretching of C=C absorption from 1492 to 1478 cm −1 . Larger absorption peaks appear at 1350 and 1010 cm −1 and correspond to symmetrical stretching and in-plane bending of the O=S=O functional group [ 40 , 41 , 42 ]. The appearance of an enlarged shoulder at 1225 cm −1 is ascribed to asymmetric stretching [ 43 ].…”