"LABORATORY SCALE PRODUCTION OF HYDROXYPROPYLMETHYLCELLULOSE (HPMC) IN A GAS-TIGHT REACTOR UNDER PRESSURE AND ITS APPLICATION IN CEMENT PASTE"

Abstract

"Unfortunately, cellulose, which is the most abundant of natural polysaccharides in the world, and is found in high amounts in cotton and the waste/by-products of textile factories, cannot be recycled sufficiently. As an attempt to find a solution to this problem, in this study, a by-product of the towel production process, called “towel clippings” (TC), was used as a source of cellulose for obtaining HPMC. HPMC was synthesized for the first time from the reaction of cellulose, propylene oxide (PO) and chloromethane (CM) under pressure in a gas-tight laboratory scale reactor and then evaluated as an additive in cement paste. The HPMC was characterized by 1H(13C)-NMR, FT-IR, XRD, DTA/TGA and SEM techniques. Additionally, the DS values were determined using the 13C-NMR technique. The highest viscosity was obtained as 2740 cP in HPMC-5 with the highest DS value of 2.86. While the setting time of the standard cement paste, without any additives, started at the 140th minute and was completed at the 250th minute, with the addition of 0.5 grams of HPMC-1 to the cement paste, the starting time was extended by 180 minutes and the finishing time was extended by 260 minutes. In this way, it has been seen that problems such as low slip resistance and low setting time of cement paste, as well as negative effects caused by working conditions, will be avoided."