【作者】 刘灿；

【导师】 顾继友；

【作者基本信息】 东北林业大学 ， 生物材料工程， 2013， 博士

【摘要】 石油能源越来越紧缺,寻找石油的替代能源变得越来越紧迫。随着能源危机的越来越严重,玉米淀粉工业发展越来越快,工业化程度越来越高。随着生化技术的发展,玉米淀粉液化产物从单一的乙醇变得多样化。当经济附加值较高的多元醇提取以后,还有一些剩余物不能被利用。本论文研究目的就是根据这些剩余物的性能,利用这些多元醇剩余物,制备一种性能稳定的达到国家标准的复合胶粘剂。本论文意义在于：a)利用生物多元醇开发了一种对环境污染小,绿色环保的生物基胶粘剂。b)使用可再生的生物多元醇制备胶粘剂,替代了传统行业中使用的石化产品,减少了石化产品的使用。c)制备生物多元醇工业中大量剩余物被有效地利用。本研究利用这些多元醇剩余物,提高了下游产品的经济附加值,延伸了玉米工业的产业链,促进生物多元醇工业的健康发展,提高了玉米多元醇行业的总体经济效益。由于生物多元醇剩余物的本身分子量小,水溶性较强等性能的限制,并不能直接作为胶粘剂使用,需要在其自身基础上进行化学共混改性。论文通过高羧基含量的氧化淀粉对小分子的醇进行扩链,降低多元醇剩余物的渗透性。使用水性异氰酸酯对多元醇胶粘剂的防水性进行改进。在氧化淀粉制备方面,通过双氧水、次氯酸钠、高锰酸钾三种氧化剂制备高羧基含量氧化淀粉。通过对制备样品的羧基含量、粘度、热力学性能(TGA、DSC)、XRD等性能指标,分析pH、温度、酸化量、氧化剂用量等因素对氧化淀粉制备的影响。双氧水制备氧化淀粉,碱性环境中制备的氧化淀粉氧化程度高,最佳pH值为9。温度较高环境中双氧水活动更活跃,制备的氧化淀粉氧化程度较高,最佳温度为T=45。C。随着氧化剂用量的增多氧化程度增高,在最优制备环境中双氧水的利用率为0.57%。次氯酸钠制备氧化淀粉,在弱碱环境中氧化剂对淀粉的氧化程度高,最佳制备条件是pH=9。温度高或低均不利于次氯酸钠对淀粉的氧化,最佳制备温度为50℃最优。次氯酸钠的用量越大淀粉氧化程度越深,在最佳制备条件下次氯酸钠的利用率为1.57%。高锰酸钾制备氧化淀粉,第一阶段的活化pH值选择11时制备的氧化淀粉氧化程度高。温度过高或者过低均不利于高锰酸钾对淀粉的氧化,最佳制备温度为40-C。酸化质量对第二阶段的氧化影响很大,酸化质量为干淀粉的11%时淀粉氧化程度深。在最佳制备条件下高锰酸钾的利用率为50.28%。相同氧化电子数下的三种氧化剂进行比较,次氯酸钠氧化能力是最强的,双氧水最差,高锰酸钾居中。次氯酸钠对淀粉的氧化程度最深,可以打破淀粉的结晶外壳,渗透进淀粉颗粒内部进行氧化反应。高锰酸钾也可以打破淀粉的结晶结构,会对淀粉结晶外壳进行腐蚀,使得外壳凹凸不平。双氧水对淀粉游离的直链和支链淀粉进行氧化,不能破坏淀粉的结晶结构,对淀粉颗粒的结晶结构影响不大。对可乳化异氰酸酯方面采用两种亲水改性剂(A、B)进行改性,分别从乳液的适用期方面,分析最佳NCO/OH摩尔比、乳化剂用量、稳定剂用量。得出亲水改性剂A最佳制备乳液条件为：NCO/OH摩尔比为160：1,乳化剂用量为2%,稳定剂添加量为0.3%最佳。亲水改性剂B最佳制备乳液条件为：NCO/OH摩尔比为80：1,乳化剂用量为1%,稳定剂添加量为1%最佳。然后对两种改性剂和阴离子改性剂DMPA进行共混改性。结果表明,亲水改性剂A体系中引入DMPA量为1%能提高乳液的适用期,达到152.9min。而亲水改性剂B体系不适合引入DMPA。分别制备羧基含量高的氧化淀粉和适用期长的乳化异氰酸酯预聚体。把氧化淀粉,乳化异氰酸酯,生物多元醇一起制备胶粘剂,最佳生物复合胶粘剂的配比为生物多元醇剩余物占总胶粘剂的40%,乳化异氰酸酯占23%,氧化淀粉添加为9%。胶粘剂的结合强度为1.105MPa。更多还原

【Abstract】 The increasing shortage of petroleum energy, alternative energy is becoming more and more urgent the search for oil. With the development of biochemical technology, the products prepared by corn starch from a single ethanol become diversified. Corn starch industry development faster and faster, the level of industrialization was increasingly high, which due to the increasingly serious energy crisis. After the polyol with higher economic value added was extracted, some residues cannot be used. The purpose of this paper is based on the performance of these residues, using these polyols residue for preparing a composite adhesive with stable property and meets the national standard. The significance of this paper is shown as follows,(a) Utilization of biomass polyol developed a green biological adhesive with little pollution to the environment.(b) Using renewable bio-polyols prepared adhesive, to replace petroleum products used in traditional industries, so as to get rid of the dependence on petroleum products,(c) A great amount of polyols residues form corn production of bio-polyols is effectively utilized. In this study, these polyols residues had good use, which improve the economic value added of downstream products, extend the industrial of corn industry, promote the healthy development of boil-polyol alcohol industry, and improve the comprehensive economic benefits of corn production of polyols industry.Bio-polyol residues had small molecular weight and better water-soluble, it cannot be directly used as adhesive, and need for chemical blending modified. The oxidized starch with high carboxyl content was use as chain extender for small molecule alcohol, and as a role of filling, thereby reduces the permeability of the polyol residues. Emulsified isocyanate was use to improve waterproof of Polyol adhesives.In the oxidized starch preparation, preparation of high carboxyl content of oxidized starch with hydrogen peroxide, sodium hypochlorite, potassium permanganate three oxidation agent. Through test the carboxyl group content, viscosity thermodynamic properties (TGA, DSC), XRD and other performance index of the sample, analyze the effect of pH, temperature, acidification, amount of oxidant on oxidized starch prepared. Draw the following conclusions:Preparation of oxidized starch with hydrogen peroxide, oxidized starch had high degree of oxidation when prepared in alkaline environment; the optimum pH value is9. Hydrogen peroxide is more active in high temperature environment, the preparation of oxidized starch with high degree of oxidation, the optimum temperature is45℃. The degree of oxidation was increasing with oxidant dosage increased, hydrogen peroxide in rate of0.57%in the optimal preparation conditions.Preparation of oxidized starch with sodium hypochlorite, products had high degree of oxidation in alkalescent environment, the best preparation condition at pH9. The high or low temperature was unfavorable to the oxidation of sodium hypochlorite on starch, the best preparation temperature is50℃. The more the amount of sodium hypochlorite, the greater the degree of oxidation starch. The utilization rate of sodium hypochlorite is1.57%under the optimal preparation conditions.Preparation of oxidized starch with potassium permanganate, products had high degree of oxidation when activation pH value of the first phase selection11. Temperature too high or too low are not conducive to oxidation starch by potassium permanganate, the best preparation temperature is40℃.Acidification quality had great effect on the second stage oxidation, the deep degree of oxidation for starch when acidification quality was11%to dry starch. The utilization rate of potassium permanganate was50.28%under the optimum preparation conditions.Comparing three kinds of oxidant with equivalent oxidizing power, the oxidation ability of sodium hypochlorite was strongest; hydrogen peroxide was weakest, Potassium permanganate in the middle.Sodium hypochlorite had the deepest degree of oxidation on starch, can break the crystal shell of starch, and penetrate into the internal of starch granules. Potassium permanganate can also break the crystalline structure of starch, corrosion of starch crystalline shell, which make uneven for starch shell. Hydrogen peroxide was only oxidize the free amylose and amylopectin of starch, cannot damage the crystal structure of starch, it has little effect on the crystalline structure of starch granules.Then the emulsifiable isocyanate was modified with two hydrophilic modifiers (A, B). The optimum molar ratio of NCO/OH, the amount of emulsifier and stabilizer was analysis from the aspect of the application period of emulsion. The optimum conditions of prepare emulsion with hydrophilic modifier A was that the molar ratio of NCO/OH was160:1, emulsifier dosage was2%and addition amount of stabilizer is0.3%. For hydrophilic modifier B, the optimum conditions for the preparation of emulsion was that80:1of NCO/OH molar ratio,1%of emulsifier dosage and1%of the addition amount of stabilizer. Two kinds of modifiers were modified with DMPA, the results show that introducing an amount of1%DMPA to the system of hydrophilic modifier A can improve the application period of emulsion, reaching152.9min. The system of hydrophilic modifier B was not suitable for the introduction of DMPA.Finally, preparing oxidized starch with high carboxyl content and emulsifiable isocyanate prepolymer with a long period. Then mixed oxidized starch, emulsified isocyanate and bio-polyol for prepared adhesive. The best ratio of biological composite adhesive was that biological polyol residues was40%of the total, for emulsified isocyanate was23%, and9% for oxidized starch. The strength of the adhesive was1.105MPa.更多还原