In attempting to improve the procedure for isolating conifer bark full of cellulose, various pretreatment methods prior to standard chlorite extractions were studied. Using mountain hemlock (Tsuga mertensiana) bark, it was shown that pre-extraction with 1 percent anhydrous ethanolic potassium hydroxide greatly enhanced the ability of chlorite-acetic acid treatments to produce relatively “lignin”-free holocellulose. The same treatment had the same beneficial effect on Douglas-fir (Pseudotsuga menziesii) bark. It is suggested that the pretreatment may break a ligno-carbohydrate bond within the bark. Data indicated that the pre-extraction did not remove significant carbohydrates. A check of the same pretreatment given to Douglas-fir wood showed no advantage over the conventional sodium chlorite method.
You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member