【作者】 林金娜；

【导师】 陈礼辉； 黄祖泰；

【作者基本信息】 福建农林大学 ， 森林工程， 2004， 硕士

【摘要】 博采众长的复合材料代表了新材料的发展方向，得到世界各国的重视。复合材料的特点在于其不仅能保持原组分的特色，而且还可通过复合效应，克服单一材料的局限性，使之具有原组分材料所不具备的性能，所以它是一种可进行预先设计的材料。在复合材料家族中，植物纤维增强热塑性树脂复合材料由于利用了丰富、廉价、可再生、可降解的植物纤维作为增强相，使之具有成本低、性能好、与环境友好等优点，已成为新世纪材料学研究的重要领域。特别是木塑复合材料的研究已取得长足进步，已在汽车工业等领域得到广泛应用。我国素有“竹子王国”的美称，本省竹资源又居全国之冠。在木材资源短缺、生态环境十分脆弱的今天，生产周期短、价廉、比强度、比模量高的竹纤维作为增强材料，研究开发竹塑复合材料具在特殊的意义，而这方面研究在国内外尚未得到应有的重视。本论文研究竹材爆破浆(竹纤维)、玻璃纤维增强聚丙烯复合材料土工网(以下简称竹塑复合材料土工网)，用其替代现有高聚物制作的土工网，应用于土木工程建设领域。竹塑复合材料土工网的研究开发对提高工程质量、节省投资、保护生态环境、充分利用竹材资源优势，提升竹材工业技术水平有重要意义。 针对木塑复合材料研究中基础性问题(纤维分散性、二相界面相容性、复合工艺与性能关系)及竹材具有与木材不同的表面化学性质和表面特征对竹塑复合效果的影响，本论文对竹纤维对撞流干燥及其分散性、竹塑复合材料制备及其性能、复合材料增强机理及土工网的研制等进行了较深入研究。 论文研究了竹纤维对撞流干燥的干燥特性，分析对撞流强化传热传质过程，探讨对撞流干燥对纤维形态、强度和分散性的影响，在国内外首次用对撞流干燥技术干燥竹纤维，为复合材料所需高度分散的竹纤维原料制备提供了技术依据。用对撞流干燥方式干燥竹纤维浆料，提高了干燥过程的传热传质效果，利用热气流与湿浆料之间产生的剪切、湿纤维之间碰撞产生的剪切摘要来分散竹纤维，防止竹纤维干燥失水后絮聚成团。在保证竹纤维质量的前提下，尽可能使用较高的干燥气流速度。干燥气流温度对干燥后纤维强度、长度和分散性影响较小，可选用较高的干燥气流温度来提高浆料的干燥速率。进入干燥系统的竹纤维浆料含水率和载带率对干燥后竹纤维原料的分散性影响较大。竹纤维对撞流干燥适宜的工艺参数为气流温度高于110℃，气流流速31 .4而s，竹纤维干燥前绝对含水率376%，载带率o.o28k眺g。 论文研究了竹塑复合材料的制备及其力学性能、热学性能和加工性能。研究结果表明，竹纤维用量是影响竹塑复合材料力学性能、热学性能和加工性能的主要因素。自制的偶联剂可明显改善竹纤维与基体两相间的相容性，增强复合材料界面的润湿和粘合强度，综合考虑复合材料的性能与经济性，较适宜的偶联剂用量为4%。用主成分分析法确定竹塑复合材料主要性能兼优的最佳竹纤维含量为27.28%。当用27.28%竹纤维和10%玻璃纤维作为增强材料时，复合材料的主要性能指标为:拉伸强度30.79MPa，伸长率9.31%;弯曲强度42.76MPa;冲击强度(缺口)7.87KJ·衬;热变形温度93.06℃:熔体流动速率1.49留10min，可满足注塑成型加工的要求。 采用扫描电子显微镜(SEM)和示差扫描量热仪(DSC)对竹塑复合材料的增强机理进行研究。通过竹塑复合材料的微观形态的分析，可以观察到纤维与基体之间的界面很模糊，被拉断的竹纤维被包埋在基体中。DSC测试可知，竹塑复合材料具有一个明显的玻璃化转变温度Tg、较高的玻璃化转变温度Tg和较高的结晶度。分析表明，竹塑复合材料具有界面相容性好、界面间的粘结力大、力学性能和热学性能好等优势。 论文以竹塑复合材料为原料，采用注塑成型的方法加工土工网。当用20%竹纤维和10%玻璃纤维作为增强材料时，竹塑复合材料土工网的拉伸强度可达到31.SKN/m，，土工网的伸长率达到10.2%，可适用于高边坡防护、膨胀土路堤溜坡处理、岸坡防冲、桥头跳车、沥青路面反射及冻胀龟裂、道路福建农林大学硕士研究生学位论文论文题目:竹塑复合材料及其土工网研究泛浆、软基处理等土木工程领域。更多还原

【Abstract】 Composite, possessing of many good qualities, is a representation of new stuff and attains the global recognition. The characteristics of composite are not only possessing of original feature but also having new performance other than former material. The plant fiber reinforced thermoplastic composite has many advantages in good mechanic function, excellent manufacture function, light weight, low price. The study on plant fiber reinforced thermoplastic composite, especially the wood fiber reinforced thermoplastic composite, is hot spot in material scientific research in new century. Our country always is called "bamboo kingdom". Bamboo fiber has many advantages in low great and price. In the poor-wood-resource times, the research on bamboo fiber composite signify much. However, the study on bamboo fiber reinforced thermoplastic composite doesn’t meet with much recognition.This item is utilized the bamboo fiber substituting the section of glass fiber and produce bamboo fiber and glass fiber reinforced polypropylene composite. This kind of composite will be applied to manufacture geotextile. Character of impinging stream drying of bamboo fibers, manufacture and properties of the composite are studied. At the same time, microscopic structure and interface modifying in bamboo fiber and glass fiber reinforced polypropylene are deeply investigated.Character of impinging stream drying of fibers is studied. Heat and mass transfers during impinging stream drying process are investigated. Effect of impinging stream drying on morphology, strength and distribution of fiber is probed. Technology of impinging stream drying is first applied to dry plant fiber pulp at home and abroad. This work could provide technical support for thepreparation of high dispersed plant fibers required for plant fiber reinforced thermoplastic composite. At the condition of maintaining the quality of fibers, high speed of hot gas stream has little effect on strength, length and distribution of fibers, so hot gas stream of high temperature can be used to intensify efficiency of plant drying. The dryness and mass flow rate of inlet pulp have much effect on distribution of dried plant fibers, so the suitable preceding water content ratio is 376%. The optimal conditions of drying bamboo fiber are: speed of hot gas stream 31.4m/s, mass flow rate 0.028kg/kg , preceding perfectly water content ratio of inlet pulp 376% and temperature of hot gas stream higher than 110 C.The production, mechanic function, thermal function and manufacturing function of composite are studied. The result shows that the quantity of bamboo fiber is main factors. The best capacity of fiber corresponding to a single property index can be confirmed by the parabola equation. Furthermore, by combined the method of main composition analysis with the parabola equation, the optimum bamboo fiber content of bamboo plastic composite is 27.28%. When bamboo fiber charge is 27.28% ,glass fiber charge is 10% and interfacial modifying agent charge is 4%, main properties of composite are as follows : tensile strength 30.79MPa, flexural strength 42.76MPa , impact strength 7.87KJ/m2 , heat distortion temperature 93.06 C, melt flow rate 1.49g/10min.The mechanism of the composite is studied with SEM and DSC. The photograph from SEM shows that coupling agent stimulates formation of resin cover in the surface of fiber, and then improves surface’s cohesive intensity and mechanic function significantly. The curve from DSC shows that the additive-bamboo fiber with the treatment with coupling agent increase glassifing temperature of composite, which implies that the surface of the fiber prevents the action of polypropylene.Finally, the bamboo fiber and glass fiber reinforced polypropylenecomposite is applied to manufacture geotexile. As the quantity of fiber increases, largest tensile strength of the geotexile increases and lengthen ration decrease. When bamboo fiber charge is 20% and glass fiber charge is 10%, main properties of geotexile made by the composite are as follows: la更多还原