【作者】 丁为民；

【导师】 阎秀峰；

【作者基本信息】 东北林业大学 ， 森林植物资源学， 2010， 博士

【摘要】 白桦是东北林区的主要阔叶树种,是黑龙江省重要的林木资源。白桦树皮是白桦采伐与加工过程中的主要剩余物,是重要的生物质资源,含有多种具生物活性的物质。本项研究以白桦树皮为原料,利用现代化工技术,形成一套获取白桦树皮精油、桦木醇、单宁类物质的完整技术,探讨桦木醇衍生物的制备与精油、单宁类物质在日化及防腐领域的利用技术以及提取剩余物的再利用技术,以此为基础建立白桦树皮的综合利用模式,主要成果如下：1.运用均匀设计法优化了桦木醇的乙醇回流提取、微波辅助提取、超声波辅助提取和超临界二氧化碳流体萃取工艺,初步探讨了连续浸提法中乙醇体积分数、提取时间对桦木醇提取效果的影响。通过对比各种提取方法的桦木醇提取率、提取物中桦木醇含量,同时考虑提取连续性、环境保护、成本、设备要求等方面因素,认为超临界二氧化碳流体萃取法提取桦木醇最具工业化应用前景。超临界二氧化碳流体萃取法的最佳工艺条件是：萃取温度32℃、萃取压力8 Mpa、萃取时间1 h。利用此条件连续萃取两次,桦木醇平均提取率达到85.27%,纯度达到67.86%。以液固比为15：1-20：1(mL：g)的乙酸乙酯对各种不同提取方法所得白桦树皮提取物中的桦木醇进行初级分离纯化,桦木醇溶出率均达到或超过95%,效果好且符合环保要求,以无水乙醇为溶剂,在液固比为30：1(mL：g)的条件下,进行重结晶,桦木醇的纯度最高可达98.13%,该方法适于大规模分离纯化桦木醇且产品纯度能够满足药用研究要求。2.采用正交试验设计,确定了白桦树皮精油超临界流体萃取的较佳工艺条件：萃取温度50℃、萃取压力45 MPa、萃取时间1 h,白桦树皮精油得率达到0.54%。以水-乙醇溶液为溶剂,运用均匀设计法优化了白桦树皮单宁的传统热提取和超声波辅助提取工艺。综合各方面因素,认为超声波辅助提取法提取白桦树皮单宁更具应用前景,在乙醇体积分数为30%、提取时间为2 h、提取温度为35℃、超声波功率为250 W、液固比为18.5：1(mL：g)的条件下超声波辅助提取白桦树皮中单宁类物质,提取物得率达到12.57%,提取物中单宁类物质含量达45.68%。3.在上述研究的基础上,通过对不同提取路线进行比较,选定超临界二氧化碳萃取桦木醇-超临界二氧化碳萃取精油-超声波辅助水-醇提取单宁的依次提取为较优提取路线。按此工艺路线处理白桦树皮,避免了提取过程中桦木精油、桦木醇、桦木单宁相互影响,符合环保要求,单元生产成本低、利用效率高。4.探讨了以桦木醇为原料,利用三氯异氰尿酸/TEMPO体系将桦木醇氧化至桦木醛,再用Ag2O/KOH体系氧化至桦木酸合成路线的可行性,此合成路线避免了3α-异构体的生成,具有一定的应用前景。对桦木醇的C-30位进行了初步修饰,得到30-溴代-3,28-二乙酰化桦木醇和30-溴代桦木醇两种桦木醇衍生物。将超临界CO2流体萃取法得到的白桦树皮精油用于制备水基香精,确定吐温-60、OP-10为白桦树皮精油较优的增溶剂。以白桦树皮单宁类物质提取物做助剂制备转化型除锈防锈底漆,该防锈底漆在耐化学性和抗水性等方面都比普通防锈漆优越。5.探讨了白桦树皮精油-桦木醇-单宁提取剩余物再利用技术。以提取剩余物为原料,在水热反应釜中,以体积分数为80%的1,4-丁二醇水溶液作溶剂、提取温度为220℃、提取时间为90 min、液固比为14：1(mL：g),提取木质素,得率可达36.3%。通过红外光谱分析,确定高沸醇溶剂法所得木质素中存在较多的活性基团,具有一定的应用价值。以提取剩余物为原料,采用氯化锌法制活性炭,在一定的工艺条件下,氯化锌溶液质量分数20%、活化时间90 min、活化温度600℃,制得活性炭产品,得率为54.6%,产品的碘吸附值为959.3 mg/g；亚甲基蓝吸附值为12.6 mL/0.1g有助于白桦树皮的全面利用。更多还原

【Abstract】 White birch(Betula platyphylla) is one of the mainbroad-leave tree species in northeast forestry of China, it is an important forest resource in Heilongjiang Province. White birch bark is the main residues of the process of harvesting and processing of white birch, it is an important resource of raw material, containing a variety of biologically active substances. In this study, we use the white birch bark as raw material, applying modern chemical technology to form a complete set of technologies to extract essential oil, betulinol and tannin substances from white birch bark, we put more effort into the exploiture of the preparation of betulin derivatives, the improvable technology of essential oils and tannin substances in the domain of daily use chemical industry and anti-corrosion, and the technology of re-use of the extracted residues to establish the model of comprehensive use of white birch bark. Main results are as follows:1. Use uniform design to optimize the process of reflux extraction with ethanol and microwave-assisted extraction, ultrasound-assisted extraction and supercritical carbon dioxide fluid extraction of betulin. In preliminary study, we investigate the effect of the volume fraction of ethanol, extraction time on the continuous extraction of betulin. By comparing the aspects of extraction rate of betulin and the content of the extraction of betulin, taking account the factors such as the continuity of extraction, environmental protection, cost and equipment requirements at the same time, we think supercritical carbon dioxide fluid extraction method has distinguished prospects of industrial application in the extraction of betulin. The optimum conditions of supercritical carbon dioxide fluid extraction was determined, the extraction temperature, extraction pressure, extraction time were 32℃,8 Mpa,1 h, respectively. The average extraction rate and purity of betulin after a twice continuous extraction in this condition were 85.27% and 67.86%. Primary isolation and purification of betulin from the extractive of white birch bark by different extraction methods were created by ethyl acetate at liquid-solid ratio of 15:1-20:1 (mL:g). the dissolution rates of betulin can reached.or exceeded 95%, this method was more effective and meet the environmental requirements. After the re-crystallization using anhydrous ethanol as solvent, in liquid-solid ratio of 30:1 (mL:g), the purity of betulin up to 98.13%, the method suitable for large-scale separation and purification of betulin and the purity of the product meet the requirements of medical research.2. Using orthogonal design to optimize the extraction conditions of essential oil by supercritical fluid extract method from white birch bark, the result was medetermined: extraction temperature is 50℃, extraction pressure is 45 MPa, extraction time is 1 h, under this condition the yield of essential oil reached 0.54%. With water-ethanol solution as the solvent, use uniform design to optimize the process of traditional hot extraction and ultrasound-assisted extraction of tannins from white birch bark. Through the comprehensive analysis of all the factors, we think ultrasound-assisted extraction method has distinguished industrial application prospects in the extraction of tannins. Under the condition:the volume fraction of ethanol is 30%, extraction time is 2 h, extraction temperature is 35℃, ultrasonic power is 250 W, the ratio of liquid-solid is 18.5:1 (mL:g), the yield of extractive reached 12.57%, the content of tannin up to 45.68%.3. Based on the result of former research, through the comparaition of the different extraction routes, we establish the best extract route composed of the extraction of betulin by supercritical carbon dioxide method, the extraction of essential oils by supercritical carbon dioxide method and Ultrasound-assisted extraction of tannin with alcohol aqueous solution as solvent by turns. Followed by this extraction process, we can avoid interacting of essential oil, betulin and betulinic in routine extracting, craft route of white birch bark, meet the environmental requirements, the cost of unit production is low and has high efficiency.4. Use betulin as raw material, investigate the feasibility, of synthetic route of the transformation from betulin to betulinic aldehyde by oxidation catalysised with TCCA/ TEMPO system and then oxidized to betulinic acid with Ag2O/KOH system. This synthetic route can avoid the generation of 3α-isomer, has a certain value of application. Initial modification was made at C-30 position of betulin by chemical reaction, two kinds of derivatives of betulin:30-bromo-3,28-2 acetylated betulin and 30-bromo-betulin were created. We prepare water-based fragrance oils from essential oil extracted by supercritical carbon dioxide method from white birch bark and find that Tween-60 and OP-10 were better solubilizers of essential oil extract from white birch bark. New anti-rust paint was prepared by using tannin extractive extract from white birch bark as solubilizer. We find that the new anti-rust paint was superior to common anti-rust paint in the performance of chemical resistance and water resistance.5. The reuse technology of the extracted residues of essential oil, betulin and tannin from white birch bark was exploited. Both the extractions of lignin with 1,4-butanediol aqueous solution and the preparation of activated carbon by chemical activation with ZnCl2 were investigated through orthogonal design. Based on the result, the optimum extraction conditions were determined:the concentration of 1,4-butanediol aqueous solution, extraction temperature, extraction time and the liquid-solid ratio were 80% (v/v),220℃,90min,14:1 (mL:g), respectively. The yield was 36.3%. The information on the surface functional groups and structures of the carbons was provided by FT-IR spectroscopy. To the preparation of activated carbon, the influence of process variables such as the concentration of ZnCl2 solution, activation time, and activation temperature was studied. The optimum preparation conditions were also determined:the mass fraction of ZnCl2 solution is 20%, activation time is 90 min, activation temperature is 600℃, the adsorption value of iodine and methylene blue, the yield of activated carbon products prepared under this condition were 959.3 mg/g; 12.6 mL/0.1g; 54.6%, respectively.更多还原