【作者】 张安定；

【导师】 丁辛；

【作者基本信息】 东华大学 ， 纺织工程， 2004， 硕士

【摘要】 最近几十年，由于合成纤维的发展，各种价格低廉，性能优良的合成纤维制品的兴起，黄麻制品逐渐在市场竞争中萎缩。黄麻是每年生再生纤维，具有密度低、强度大、价格低等特点，所以用黄麻纤维增强塑料对降低材料的成本以及提高材料的比强度和比模量都是非常有利的。开发黄麻纤维增强复合材料，对充分利用我国丰富的黄麻纤维资源优势具有重大意义。 本文主要讨论了注塑成型制成的黄麻纤维增强聚丙烯的制备方法和其性能。将纤维含量分别为10Wt％、20Wt％和30Wt％的试样进行比较，分析纤维含量对黄麻纤维增强聚丙烯拉伸、弯曲和冲击性能的影响；将纤维分别切成约3mm、5mm和10mm长制成试样进行比较，分析纤维长度对黄麻纤维增强聚丙烯拉伸、弯曲和冲击性能的影响。最后，比较了苎麻纤维增强聚丙烯与黄麻纤维增强聚丙烯的性能以研究不同纤维对增强聚丙烯的影响。 得到如下主要结论： 1、黄麻纤维增强聚丙烯的性能比聚丙烯的性能有明显改善。 2、对于未经表面处理的黄麻纤维，当纤维含量在10Wt％和30Wt％之间时，黄麻纤维增强聚丙烯试样拉伸强度随着纤维含量增加没有明显变化；弯曲强度和模量都随纤维含量增加而递增。当纤维长度在3mm和10mm之间时，黄麻纤维增强聚丙烯试样拉伸强度随着纤维含量增加而递增，但增加程度不大；弯曲强度和模量都随纤维长度增加而递增。黄麻纤维增强聚丙烯拉伸强度提高不显著是由于黄麻纤维与聚丙烯界面结合不理想的结果。 3、黄麻纤维掺入聚丙烯导致黄麻纤维增强聚丙烯试样的伸长率减小，即黄麻纤维增强聚丙烯的延性下降。当纤维含量在10Wt％到30Wt％之间时，试样的延性随纤维含量增加而递减。当纤维长度在3mm和10mm之间时，试样的延性也随纤维长度增加而递减。 4、黄麻纤维掺入聚丙烯导致黄麻纤维增强聚丙烯试样的冲击韧性摘要与断裂韧性下降。当纤维含量在10Wt%到3OWt%之间时，两种韧性都随纤维含量增加而递减。黄麻纤维的存在使得纤维增强聚丙烯模量得到明显的改善，但是在提高其模量的同时，也使其韧性有所下降。 5、黄麻纤维增强复合材料的耐热性随纤维含量增加而递增。当纤维长度在3mm和10mm之间时，复合材料的耐热性也随纤维长度增加而递增。 6、与黄麻纤维类似，芒麻纤维的加入使聚丙烯的强度、模量和热变形温度提高，但使其韧性和延性降低。由于两种麻纤维的形状、脱胶程度等都有较大的差别，因此，比较两种不同纤维对聚丙烯增强效果的影响需要进一步的严格试验条件。 总之，黄麻纤维的加入使聚丙烯的强度、模量和耐热性提高，但使其韧性和延性降低。另外，要使黄麻纤维增强聚丙烯性能有较大提高，改善黄麻纤维和聚丙烯之间的界面强度是必要的。更多还原

【Abstract】 Recent a few decades, all kinds of products made of jute reduce rapidly in the market because the competition of cheaper synthetic fibers. Because jute is annually regenerative, being low density, high strength and low price, it is very beneficial to be used as reinforcing fiber in composite industry for the decrease of cost and improvement of specific strength and specific module. Using jute fiber in the fields of reinforced polymer composites has a great meaning to make full use of jute resource in our country.In this thesis, properties of jute fiber reinforced polypropylene samples prepared by injection molding are studied. The tensile, flexural and impact behaviors of samples with different fiber contents are investigated by comparing three kinds of composites whose fiber contents are 10, 20 and 30Wt%; The tensile, flexural and impact behaviors of samples with different fiber length are also investigated by comparing three kinds of composites whose fibers are respectively chopped to approximately 3mm, 5mm and 10mm in length. The comparison between properties of jute fiber reinforced polypropylene composite and ramie ones is made to study the influence of different fiber properties in reinforced composites.The main conclusions are as follows:l.The properties of jute fiber reinforced polypropylene composite are better than those of pure polypropylene.2. Without the modification of fiber surface, when the jute fiber content is between 10Wt% and 30Wt%, the tensile strength of jute fiber reinforced polypropylene composite samples show little change with increasing fiber content. The flexural strength and module of samplesincrease with increasing fiber content. Their tensile strength and module also increase with increase in fiber length when the jute fiber length is between 3mm and 10mm. The little improvement of tensile strength of jute fiber reinforced polypropylene composite is due to the poor interfacial adhesion between fiber and polypropylene.3. The elongation of jute fiber reinforced polypropylene samples sharp decreases after adding jute fibers when compared to pure polypropylene, namely the ductibility of jute fiber reinforced polypropylene decreases. When the jute fiber content is between 10Wt% and 30Wt%, the ductibility of samples decrease with increasing fiber content. The ductibility also increases with increase in fiber length when the jute fiber length is between 3mm and 10mm.4. The impact toughness and fracture toughness of the composite samples decrease after adding jute fibers when compared to pure polypropylene. At the same time they decrease with increasing fiber content when the jute fiber content is between 10Wt% and 30Wt%. The module of composite is remarkably improved after adding jute fibers but the toughness decreases.5. The temperature resistance of jute fiber reinforced polypropylene composite increase with increasing fiber content. When jute fiber length is between 3mm and 10mm, the temperature resistance of composite also increases with increase in fiber length.6. Like sample of jute fiber reinforced composite, the tensile strength, flexural strength, module and temperature resistance of ramie fiber reinforced polypropylene are improved but its toughness and ductibility decrease. Because there is a great deal of difference in shape and gum content of two fibers, further experiments needed in order to study the influence of different fiber properties in reinforced composites.To sum up, the tensile strength, flexural strength, module andtemperature resistance of jute fiber reinforced polypropylene are improved after adding jute fibers but its toughness and ductibility decrease. In addition, it is necessary for better capabilities of jute fiber reinforced polypropylene to improve the interfacial adhesion between jute fiber and polypropylene.更多还原