Synthesis and properties of hydroxyethyl carboxylcellulose (HECMC)

Hydroxyethyl carboxylmethyl cellulose (HECMC) is a kind of polymer obtaine by natural cellulose after chemical modifie one-one ether. It is a mixture of carboxyl methyl ions and non-ion hydroxyethyl cellulose in the cellulose unit. Which has the advantages of both carboxymethyl cellulose (CMC). It also has the advantage of hydroxyethyl cellulose (HEC), which can be compatible with divalent cations, overcoming the disadvantage that CMC is not a good viscosity control agent in high salt solution.

Therefore, the application prospect of HECMC is very broad, abroad has been widely used in oil exploitation and other sectors of [25]. The traditional synthesis method of HECMC is to use ethylene oxide and- -chloroacetic acid as ether chemical agent. Due to the low boiling point of ethylene oxide, the gas is at room temperature. And the transportation and storage is many inconvenient and the price is high. In this paper, HECMC was synthesize by chlorine ethanol and chloroacetate with the low price and the convenience of ethylene oxide production process. And the structure of HECMC was characterize, and the synthesis factors and performance of HECMC were systematically studie.

Effect of etherification agent dosage on etherification substitution degree; Fig.1.Fig. 2 For the effect of etherant chlorothanol and- -chloroacetic acid on the substitution MS and Ds. As can from the figure, the increase of the amount of etherification. As seen by Fig.2, substitution of hydroxyethyl did not affect subsequent substitution of the carboxymethyl group. In 1mol of cellulose, the dosage of monochloroacetate was increase to 1.72 mol before. And with the increase of DS, and the increase of DS was slowe down.

This is due to the increase,a byproduct of the hydroxyylation reaction, and the following side reactions occur:

That 62 C is optimal at cellulose hydroxyylation. Leading to a decrease of MS. During carboxymethylation. It was confirmed that DS decrease with increasing temperature, mainly due to the accelerate hydrolysis of monochloroacetic acid at high temperatures. This is consistent with the optimal value of the carboxymethylation temperature of 40 to 50 C.


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