Nuclear chemistry

Catalysis

Adsorption

Composite number

Engineering

Polymer chemistry

Curing (chemistry)

Materials science

Rhodamine B

Differential scanning calorimetry

Chitosan

Chemical engineering

Porosity

Physical chemistry

Thermodynamics

Physics

Organic chemistry

Microstructure

Composite material

Chemistry

Infrared spectroscopy

Fourier transform infrared spectroscopy

Thermal stability

Photocatalysis

Reactive and Functional Polymers

In this study, two bio-based benzoxazines, PH-f and SA-f, were synthesized and used to prepare benzoxazine/chitosan (CS) composites of PH-f/CS and SA-f/CS and their corresponding curing products poly(PH-f)/CS and poly(SA-f)/CS. Differential scanning calorimeter (DSC) and Fourier-transform infrared spectroscopy (FTIR) spectra show that, compared with poly(PH-f)/CS, the formation of imine-linkages (C=N) between SA-f and CS accelerates the benzoxazine ring-opening reaction and lowers the curing temperature of SA-f/CS. Although poly(PH-f)/CS and poly(SA-f)/CS have lower thermal stability than corresponding pure polybenzoxazine, it is still high and their LOI values are >35, indicative of good flame retardancy. Due to the formation of CN bonds between SA-f and CS, the poly(SA-f)/CS composite has more regular surfaces and a more uniform pore distribution than poly(PH-f)/CS, with a specific area of 1.135 m2/g and porosity of 97.5%. The unique pore structure of the poly(SA-f)/CS composite gives it high adsorption capacity (reaching 95% for rhodamine B within 48 h), suggesting that it is a promising adsorption material.

Chitosan/biological benzoxazine composites: Effect of benzoxazine structure on the properties of composites