【作者】 奚莺；

【导师】 陈南梁；

【作者基本信息】 东华大学 ， 纺织工程， 2007， 硕士

【摘要】 随着全球能源问题和环境问题的出现,对生态复合材料的开发与研究产生了重要的意义。人们逐渐关注于天然植物纤维在复合材料中的应用,尤其是具有众多优点的麻纤维,它的优点在于:耐磨、断裂强度高,完全可以替代玻璃等纤维生产出性能较好的复合材料;麻纤维属可再生资源,且资源广阔;废弃以后麻纤维可在自然条件下降解。近年来国内外对麻纤维增强热塑性树脂基复合材料的发展较快,产品可用于汽车、建筑、交通运输等各方面,尤其是用于汽车的内饰件。虽然麻纤维增强热塑性树脂基复合材料在国内外都已有研究,但对麻纤维连续状增强体及其制作方法的研究却很少。本课题将以亚麻纱线作为连续状增强体,聚丙烯复丝作为基体;采用包覆纱的浸渍工艺,制作了pp/亚麻包覆纱后浸料;再将包覆纱制成机织平纹布作为预成型件;通过热压成型工艺制作成复合材料板材;同时还制作了对亚麻纱线进行碱处理和偶联剂处理的复合材料板材。研究了包覆纱和机织平纹布的制作工艺及热压成型工艺,还考察麻含量和预成型织物密度和亚麻纱线前处理对复合材料拉伸性能的影响,对生产中出现的问题提出了解决方案。在包覆纱制作过程中找到了中空捻度和空心锭转速两个工艺参数对包覆纱麻含量和包覆紧密度的影响,并在麻含量和两个工艺参数之间建立了回归方程,为生产提高了方便。在机织平纹布织造时,由于包覆纱表面光滑和纱线刚性大使织物纬纱实际密度达不到设计值,通过多次试验得出使设计纬纱密度和实际纬纱密度达到一致的方法。在热压工艺研究中对热压时间、温度和压力三因素进行了单因子和正交实验,以复合材料板材拉伸强度作为指标找到了最佳的热压工艺。对不同制作方法生产的麻纤维增强热塑性树脂基复合材料板材的比较,证明了本课题采用的包覆纱法能生产出性能较好的复合材料。对不同麻含量和织物密度的复合材料板材进行拉伸性能测试,研究麻含量和织物密度对复合材料板材拉伸性能的影响。在对亚麻纱线进行碱处理和偶联剂处理后,发现纱线性能发生变化,碱处理纱线性能变化更大;处理后复合材料拉伸强度变大,弹性模量变小,碱处理的复合材料改变程度更大。本课题开发了连续状的麻纤维作为增强体的热塑性树脂基复合材料,解决了生产中的一系列问题,提高了麻纤维增强热塑性树脂基复合材料的性能,这对绿色复合材料的发展具有重大的意义。更多还原

【Abstract】 With the problem of energy sources and environment, it becomes important to develop green composites and study on it. People are getting to pay more attention to the application of cellulosic fiber in composites, especially to the fibers like flax, ramie, jute, sisal. Theses fibers have many excellences. First of all they have good abrasion resistance and high tenacity which make them to substitute the glass fibers in composites. Secondly they belong to regenerative source, and they are also abundance. Lastly they can degrade in nature condition after being abandoned. Recently, thermoplastic resin composites reinforced with fibers like flax, ramie, jute, sisal got development quickly and products have been applied to auto, architecture, traffic, especially in inner decoration of auto.Although there have been many studies on fibers like flax, ramie, jute, sisal reinforced thermoplastic composites in home and out, development of continuous fibers and research of its producing techniques are so little. In this paper, the flax yarn will be used as the continuous reinforcement and the Polypropylene multifilament will be used as thermoplastic resin matrix. The two things will be made into a pp/flax covered yarn, which are ready to be woven into a plain fabric. The flax/pp composite board is accomplished by hot-pressing molding. Some other composite boards are also made, whose flax yarn haven been pretreated. Techniques of covered yarn spinning and plain weaving and hot-pressing are studied. The effect that flax quantity and fabric density and pretreatment have on composites’ tensile property is also researched and many problems in producing process are solved.During the spinning of covered yarn the relation between the flax quantity, covered tightness and the hollow twist, hollow-spindle rotate speed is found, which provides convenience in later manufacture.In weaving the actual weft density can not accord with the designed weft density because of covered yarn’s slippery surface, low flexibility, and this problem has been solved.In hot-pressing single experiment and orthogonal experiment of temperature, time and pressure are designed to look for a best hot-pressing condition.The composite made by the means of covered yarn is better than composites made by other methods. Tensile properties of composites with different flax quantity and fabric density have been tested and compared.The flax yarn is treated by alkali and coupling agent, after which the properties of flax yarn are changed, especially the alkaline treated yarn. The tensile properties of composites were tested. The results showed that the tensile strength is increased while the tensile modulus is decreased, especially the composites by alkaline treatment.In this paper the continuous flax fiber reinforced Polypropylene composite is accomplished and many problems have been solved to improve composite’s properties, which is significant for the development of green composites.更多还原