{"title":"Selülozun TBAF/DMSO Çözücü Sisteminde KH2PO4 ve Na2HPO4 Tuz Karışımı Yerine Transesterifikasyonunda Katalizör Olarak Potasyum Karbonat","authors":"Emir ERİŞİR, Esat GÜMÜŞKAYA","doi":"10.17475/kastorman.1367919","DOIUrl":null,"url":null,"abstract":"Aim of study: This study's goal is to evaluate potassium carbonate as a catalyst for the transesterification of cellulose dissolved in TBAF/DMSO and to identify the optimal reaction conditions. Material and methods: First, a solvent system consisting of 33 g TBAF and 165 g DMSO was prepared for 10 g dissolving pulp in this solvent system for one hour, then the cellulose solution was generated. The catalysts were added to the solution. At reaction temperature, vinyl acetate was added to the solution and the 70-h transesterification process was started. The product was precipitated in ethyl alcohol and washed with water on a sieve, and then dried at room temperature. The effects of changes in catalyst ratio and temperature on bond acetyl groups were investigated by heterogeneous saponification method, FTIR, XRD, DSC, viscosity and solubility test. Main results: The samples' DS values ranged from 1.39 to 2.37 and using phosphate salt mixture catalyst and increasing the ratio of catalyst increased the DS. FTIR and XRD data revealed that acetylation was effective. DSC thermograms showed a minor endotherm at 283.3-291.2°C, and it was identified as the melting point. With potassium carbonate, the viscosity and the solubility of the products increased. Highlights: Cellulose in TBAF/DMSO could be acetylated using potassium carbonate as the catalyst. Potassium carbonate's catalyst activity was weak on DS.","PeriodicalId":17816,"journal":{"name":"Kastamonu University Journal of Forestry Faculty","volume":null,"pages":null},"PeriodicalIF":0.8000,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Kastamonu University Journal of Forestry Faculty","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.17475/kastorman.1367919","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"FORESTRY","Score":null,"Total":0}
引用次数: 0
Abstract
Aim of study: This study's goal is to evaluate potassium carbonate as a catalyst for the transesterification of cellulose dissolved in TBAF/DMSO and to identify the optimal reaction conditions. Material and methods: First, a solvent system consisting of 33 g TBAF and 165 g DMSO was prepared for 10 g dissolving pulp in this solvent system for one hour, then the cellulose solution was generated. The catalysts were added to the solution. At reaction temperature, vinyl acetate was added to the solution and the 70-h transesterification process was started. The product was precipitated in ethyl alcohol and washed with water on a sieve, and then dried at room temperature. The effects of changes in catalyst ratio and temperature on bond acetyl groups were investigated by heterogeneous saponification method, FTIR, XRD, DSC, viscosity and solubility test. Main results: The samples' DS values ranged from 1.39 to 2.37 and using phosphate salt mixture catalyst and increasing the ratio of catalyst increased the DS. FTIR and XRD data revealed that acetylation was effective. DSC thermograms showed a minor endotherm at 283.3-291.2°C, and it was identified as the melting point. With potassium carbonate, the viscosity and the solubility of the products increased. Highlights: Cellulose in TBAF/DMSO could be acetylated using potassium carbonate as the catalyst. Potassium carbonate's catalyst activity was weak on DS.
研究目的:本研究的目的是评价碳酸钾在TBAF/DMSO中溶解纤维素酯交换反应中的催化作用,并确定最佳反应条件。材料和方法:首先,制备由33 g TBAF和165 g DMSO组成的溶剂体系,将10 g溶解纸浆在该溶剂体系中溶解1小时,然后生成纤维素溶液。将催化剂加入到溶液中。在反应温度下,将醋酸乙烯加入到溶液中,开始70 h的酯交换过程。产品在乙醇中沉淀,在筛子上用水洗涤,然后在室温下干燥。采用非均相皂化法、红外光谱(FTIR)、x射线衍射(XRD)、DSC、粘度和溶解度测试等研究了催化剂配比和温度的变化对键上乙酰基的影响。主要结果:样品的DS值在1.39 ~ 2.37之间,使用磷酸盐混合催化剂及增加催化剂的比例均可提高样品的DS值。FTIR和XRD数据表明乙酰化是有效的。DSC热图显示在283.3-291.2℃有一个小的吸热,并确定为熔点。加入碳酸钾后,产品的粘度和溶解度都有所提高。在碳酸钾的催化下,TBAF/DMSO中的纤维素可以发生乙酰化。碳酸钾对DS的催化活性较弱。