【作者】 郭安福；

【导师】 李剑峰；

【作者基本信息】 山东大学 ， 机械制造及其自动化， 2011， 博士

【摘要】 严重的环境污染、大量的资源能源消耗,足制约21世纪可持续发展的重大问题。为治理“白色污染”,目前国内外已有多种绿色产品推出：淀粉基塑料类、纸浆模塑类、生物质全降解类等。其中,生物质全降解类餐盒是以植物纤维(稻草纤维、秸秆纤维、蔗渣纤维)和淀粉为主料,其他添加剂为辅料,经过发泡成型、喷涂防水防油胶、杀菌包装等工艺生产出的绿色环保产品。该绿色产品具有原料可再生、环境污染小、生产成本低等优点,是塑料产品的最佳替代品。目前,生物质全降解一次性餐饮具制品存在着成型机理不明确、成分配伍不成熟、核心生产装备不完善、生物质全降解材料基础性能研究较少和国内外缺乏有效的评价标准等问题。因此,发展生物质全降解一次性餐饮具制品关键技术成为当前亟需解决的课题。本论文在综合国内外相关研究基础上,以生物质全降解一次性餐饮具制品“成分配伍技术及成型机理-成型工艺技术-产品性能”为主线,对课题中生物质全降解制品成分配伍技术及成型机理、成型工艺技术及成型模具、力学性能、降解机理和环境友好性分析等关键技术进行了重点研究。针对生物质全降解一次性餐饮具材料成型机理、成分配伍方案不成熟问题,本文首先以热力学理论、高分子理论和胶体与界面化学理论等为指导,提出了生物质全降解材料的四步式发泡机理,研究了发泡过程中发泡剂的共混、气泡成核阶段、气泡增长阶段和固化成型阶段等四阶段相变机制。其次提出了生物质全降解材料均相成核-水桥联接成型机理,研究了成型过程中纤维、淀粉和添加剂的水桥联结成型机理及植物纤维在成型过程中的“巢拱”转变机制。最后在研究生物质全降解制品各原料物理化学特性的基础上,初步确定了几种典型生物质全降解一次性餐饮具制品成分配伍技术方案,为后续研究提供了理论基础。针对生物全降解制品的成型工艺及成型模具不成熟问题,本文首先研究了生物质全降解制品的制备过程及影响制品成型的因素,研究开发了新型模具,研究了生物质全降解制品成型工艺参数选择原则,并初步开发了几种典型生物质全降解产品的工艺参数；然后以有限元理论为基础,结合成型模具的实际工况,对模具工作过程的热场、热力耦合场进行仿真分析研究,分析了模具工作表面的温度场、应力场和应变场的工况,为模具结构优化和成型参数的优化提供了理论基础。针对生物质全降解材料缺乏基础力学性能研究的问题。本文首先研究了生物质全降解材料的微观组织形式形成机理,并采用SEM技术对生物质全降解材料的微观组织形式进行分析。其次,以生物质全降解餐盒为研究对象,通过力学性能试验,获得生物质全降解材料的力学性能参数,并利用有限元法对餐盒进行仿真,模拟餐盒在使用过程中的受压状况,确定生物质全降解餐盒的应力集中情况,并和餐盒在实验室受压状态下的情况进行对照,验证了计算机仿真的正确性,为该产品的使用和运输提供了理论基础。最后,以《GB/T 18006.1-1999一次性可降解餐饮具通用技术条件》为标准,研究生物质全降解餐盒的使用性能,主要包括：质量测定、容积测定、耐水试验、耐油试验、负重性能试验、盒盖折次试验、含水率和跌落实验等,并与淀粉基塑料餐盒、纸浆模塑餐盒的使用性能进行了对比。针对生物质全降解制品在自然环境中的降解机理问题,本文首先提出了生物质全降解材料在自然界中的双阶段降解机理,废弃制品进入到自然环境中,填埋之前以纤维素光降解和热降解为主,填埋进土壤后以微生物降解和水解为主,最后实现完全生物降解。然后以霉菌实验的方法,研究了生物质全降解餐盒在整个降解周期内的微生物生长程度和质量损失率,探讨了试样大小、环境条件对降解性能的影响,并把这些降解指标与作为阳性对照的滤纸和作为阴性对照的聚乙烯塑料进行了对比分析。同时,还与纸浆模塑餐盒、淀粉基塑料餐盒的降解性能进行了对比。针对生物质全降解制品缺乏有力环境友好性评价的问题,本文首先建立了可降解包装材料的绿色度评价指标模型,运用全生命周期理论和模糊层次分析对其进行了评价和分析；其次,通过问卷调查得到定性评价后,利用概率统计的原理对数据进行了处理,构造比较矩阵,并采用和积法计算最大特征根和特征向量,得到各指标的相对重要度。然后又计算得到各指标相对于被评价产品的综合重要度。用逻辑推理指派法确定各指标的隶属函数后,得到该指标的隶属度。根据各评价指标的隶属度和综合重要度运用线形加权的方法得到的生物质全降解可降解包装材料的绿色度；最后,把6种典型可降解包装材料和传统发泡塑料包装材料的绿色度进行了对比,认为生物质类全降解包装材料具有很好的发展前景。更多还原

【Abstract】 Serious environmental pollution, a lot of resource and energy consumption are major issues that restrict the sustainable development of the world in the 21st century. At present, in order to mount environmental and legislative pressure to reduce plastic and packaging wastes, various biodegraded materials become emerge as the time requires, which include starch based plastics, pulp molding packing materials and fully-degradable packing materials, etc. Nowadays, the fully-degradable packing materials are the best substitutes for plastic packaging materials in the world. Wide application of these materials can control or eliminate the increasing white pollution problems effectively in the world. The fully-degradable packing materials derived from starch and plant fiber, such as corn starch, straw fiber and bagasse fiber, which take advantage of full biodegradability, controlled degradation, enough raw materials, reuse and mass production. However, the fully-degradable packing materials have not been put into industrialization due to some crucial problems, such as immature compatibility, imperfect core equipments, few basic researches and insufficient evaluation criterion, etc. In this study, with the synthesis and refining of relevant researches at home and abroad, main efforts have been made on the methodology and key technologies of the fully-degradable packing materials, based on the strategy of"compatibility mechanism-forming process and mechanism-product performance"’Due to the immature compatibility of the fully-degradable packing materials, the forming process and mechanism of the fully-degradable packing materials were investigated on the basis of analysis of molecular structure and physical-chemical characteristic of plant fiber and corn starch. Combined with the working principle of core equipment mould, the technological parameters of forming process were studied. The technological process of fully-degradable packing materials was introduced, which established the foundation for the following study.Aiming at the imperfect design of core equipment molding, the hot-force coupling field of the mould in the working process was simulated. And the temperature field, the stress field and the strain field of the working surface of the molding were accomplished, which provided theoretical basis for the mould structure and processing parameters optimization.In this paper, the mechanical properties of the fully-degradable dishware were presented by tensile tests, which included Elastic Modulus, Poisson’s Ratio and Tensile Strength. Finite element models of the fully-degradable dishware were established by using the experimental results of the mechanical properties. The rule of the stress and strain distribution of the plant fiber and starch dishware under outside load was found with finite element method, which was verified by the experimental results, and the force-deformation curve of the fully-degradable dishware was found The results were of significance to its design, transport and application. Meanwhile, The performance of the fully-degradable dishware was studied, which included gravimetry, volume, weight bearing experiment, dropping experiment, hot water resistance experiment, hot oil resistance experiment, fold experiment and moisture content, etc.The biodegradability of the fully-degradable dishware was studied by isolating funguses from compost. The fungal growth degree and the weight loss rate of these materials were analyzed in experimental period. The experimental results showed that the growth grade of these materials was the V grade and the weight loss rate was 41.59%. These results revealed the fast degradation of these materials in the presence of funguses. In addition, the experimental results indicated that the size of sample had no significant influence on the biodegradability of these materials. As a contrast, the biodegradability of other materials, such as pulp model dishware, starch-plastic dishware, cellulose filter paper and polypropylene, were also analyzed.The indexes system of green degree of the fully-degradable packaging materials was built and the Fuzzy Analytical Hierarchy Process (FAHP) methodology was employed to analyze and assess this system. The qualitative assessment gained by survey and the statistics theory were both employed to deal with the qualitative data. The pair-comparison matrix was built and the maximum characteristic root and vector were computed using the sum-product method. Then the relative importance degree of every influence factor was computed, and also the composite importance degree of every influence factor was gained. The membership function of every influence factor was established by logical reasoning assignment method, and then the membership degree was gained. According to the composite importance degree and the membership degree of every influence factors, the green degree of biodegradable packaging materials was generally assessed. Finally, Comparing with the green degrees of six kinds of biodegradable packaging materials with foamed plastics materials, we are convinced that the biodegradable packaging materials had wide development prospects.更多还原