The grafting reaction performed by dissolved chitosan in acrylic acid solution for preparing super absorbent could decrease solvent acetic acid and some processes.The super absorbent of chitosan grafted acrylic acid with absorbing distilled water more than 800 times,running water more than 500 times and 0.9%NaCl solution 130 times has been obtained.The infrared spectra and chemical analysis method were adopted to analyze the structure of chitosan grafted acrylic acid and the properties of absorbent material.The best process conditions are:the mole ratio of chitosan and acrylic acid is 1.00/1.40;the initiator concentration [Mn3+]=0.006mol·L-1;the grafting reaction temperature is 90℃ and the grafting reaction time is 1.5 h.
The methods using EDTA and HCl to remove CaCO3 in preparation of Chitin were studied by IR spectrometer and analyzing the properties of chitin.The results showed that EDTA could replace HCl in the production of chitin for removing CaCO3.Especially owing to the mechanism of removing CaCO3 that EDTA possessed,there was nearly no damage to the molecular chains of chitin during the process of removing CaCO3.The molecule mass of its product was bigger than that product treated by HCl for removing CaCO3.Therefore,The high relative molecular mass chitin and chitosan could be prepared in the same condition,and all the other properties such as productivity,degree of deacetylation and color were better than that product treated by HCl.Furthermore,this process could reduce the pollution in production of chitin,and the cost was not higher than the process with HCl.
