壳聚糖改性及其在铬鞣中的应用研究

The Study on the Modification of Chitosan and the Application in Chrome Tanning Process

本文对脱乙酰度为 90 7%的壳聚糖降解成分子量为 5 0 15 ,10 0 2 0 ,15 80 0三个不同级分 ,并对之进行了N ,O—羧甲基化反应 ,改性物应用于铬鞣吸铬 ,结果表明 ,分子量较低 ,取代度较高时 ,具有较好的吸铬作用 ,废铬鞣液中铬含量在 0 5 g/L(以Cr2 O3 计 )以下。

Chitosan (D.D=90.7%,η=5～6×10 6)was degraded to low molecular weight components whose η was5015,10020 and 15800 respectively.The degraded chitosan was modified through N,O-carboxylmethylation with monochloroacetie acid.The modified products were applied in the chrome tanning process,the results showed that the product with lower molecular weight and higher substitution degree has better chrome exhaustion ability.The chrome content in the waste tanning liquor is below 0.5g/L(calculated on Cr 2O 3).