求翻译：本文主要研究醋酸纤维素的制备条件及在不同条件下取代度的比较。目前常见的是在醋酸作为溶剂，利用酸性催化剂，用适量的醋酸酐进行酯化，温度不高，时间也不常，但要经过预处理。是什么意思？

In this paper, cellulose acetate preparation conditions and under different conditions to compare the degree of substitution. Common in acetic acid as solvent, the use of acid catalyst, esterification with an appropriate amount of acetic anhydride, the temperature is not high, time is not often, but

This article examines the acetate produced conditions and under different conditions of place. It is now common in the acetic acid as a solvent, use with a suitable acid catalyst, and the acetic anhydride esters, temperature is not high, and the time is not constant, but to be pre-processed.

This article main research acetyl cellulose preparation condition and under dissimilar condition substitution value comparison.At present common is takes the solvent in the acetic acid, the use acidic catalyst, carries on the esterification with the right amount acetic anhydride, the temperature is

This major study on preparation conditions of cellulose acetate under different conditions and comparison of the degree of substitution. Is now common in acetic acid as solvent, acid catalysts, esterification with appropriate amount of acetic anhydride, the temperature is not high, not often, but to

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