Synthesis and characterization of cellulose acetate naphthoate with good ultraviolet and chemical resistance

Commercial cellulose diacetate with a degree of substitution (DS) of 2.45 was partly deacetylated to cellulose acetate (CA) with different DSs by acid-catalyzed hydrolysis and then reacted with 1-naphthoyl chloride (NpCl) to synthesize CA naphthoate (CANp). Fourier transform infrared and 1 H-NMR were used to characterize the chemical structure of CANp. The DS of naphthoate moiety (DS CANp ) could be varied from 0.18 to 0.98 by adjusting the molar ratio of –OH in CA unit to NpCl, the DS of CA (DS CA ), and the reaction time and temperature. When DS CA was 2.01 and the molar ratio was 1:6, the maximum DS CANp of the product was achieved after a reaction at 80°C for 2 h. With the increase of DS CANp , the thermal stability decreased slightly whereas the anti-ultraviolet property was enhanced. Moreover, the obtained films containing CANp exhibited good ultraviolet resistance as well as chemical resistance.