Abstract: In this study,sodium periodate was used as oxidant to oxidize the hydroxyl groups on the coir fiber selectively,and to make the coir fiber into a coir aldehyde fiber.During the process of coir fiber oxidation,the hydroxylamine hydrochloride titration was taken to determine the concentration of aldehyde.The results showed that when the concentration of sodium periodate solution was 0.7mol/L,oxidation temperature was 50 ℃,oxidation time was 3.5 h and the pH of sodium periodate solution was 2.8,the oxidation effect was best and the amount of aldehyde group in the coir fiber increased.In addition,the structure and function of coir fiber changed.The results of this study provided foundation for synthesis of new coir fiber polymer in futrue.

Key words: hydroxylamine hydrochloride, sodium periodate, selective oxidation, coir oxidized cellulose