【作者】 张鸿；

【导师】 王立久；

【作者基本信息】 大连理工大学 ， 材料学， 2008， 博士

【摘要】 沥青混凝土被广泛应用于高速公路、机场跑道、桥面铺装和城市主干道。与发达国家相比,我国的沥青路面破损问题依然严重。为了提高沥青路面使用寿命,对沥青路面进行损坏监测和公路交通智能化管理,本文结合辽宁省科技基金项目（20062147）“聚苯胺/聚丙烯导电纤维混凝土复合材料研究”和辽宁省教育厅项目（20040099）“聚苯胺/聚丙烯导电复合纤维研究”,以聚苯胺复合导电纤维为导电相材料,采用沥青玛蹄脂碎石混合料SMA-16非连续密级配,制备了聚苯胺复合导电纤维沥青混凝土。以聚丙烯纤维为基质,以苯胺单体为原料,采用现场吸附聚合法,制备了聚苯胺/聚丙烯（PANI/PP）复合导电纤维。对比研究了掺杂酸种类及其浓度、氧化剂种类及其浓度、苯胺单体含量、反应时间、反应温度等因素对聚合反应的影响,得出了最佳反应条件。聚苯胺含量达2.5%即可在基质纤维表面形成连续的导电沉积层,使纤维的电导率由原来的10^-13S/cm增大到10^-1S/cm数量级。利用红外光谱（FT-IR）、扫描电镜（SEM）、热重分析（TG）、拉伸试验等手段对PANI/PP复合导电纤维的结构与性能进行了测试。结果表明:复合纤维是聚丙烯与聚苯胺的共混体系,具有典型的皮芯型结构,皮层为墨绿色的聚苯胺沉积层,形成连续的导电通道,芯层为白色的聚丙烯基质纤维,提供物理机械性能;导电改性后纤维的强度、强力和伸长率均有下降,但热稳定性得到提高;复合纤维的耐酸性比耐碱性好,以对甲苯磺酸做掺杂酸比盐酸掺杂聚苯胺热稳定性好,脱掺杂后的复合纤维,可用其它无机酸或有机酸进行再掺杂;复合导电纤维的电导率随温度升高降低幅度较大,但几乎不受湿度影响;基质纤维细旦化、截面异形化、表面等离子体处理或共混COPET等改性处理均能提高纤维的吸附性,进而提高复合纤维表面聚苯胺含量、电导率和耐久性。经表面等离子体处理的纤维,聚苯胺含量可达到7.9%,电导率为0.17S/cm,耐水洗次数可达到55次以上,导电纤维的电导率在6个月内没有变化。采用马歇尔试验法对掺混复合纤维前后的沥青混合料的力学性能进行了测试,研究表明:聚苯胺复合导电纤维沥青混凝土的力学性能得到了明显改善,在纤维分散均匀时,随着纤维掺量的增加,稳定度、流值、空隙率均有增大趋势;对沥青混合料力学性能的提高程度由高到低依次为混配复合导电纤维、PANI/PP复合纤维、PANI/PET复合纤维、PP纤维和PET纤维;导电纤维沥青混合料试件的稳定度比掺原丝的高,这与导电改性后纤维强度明显降低的变化规律不同。掺混导电纤维的沥青混凝土电性能得到明显改善,研究表明:复合导电纤维沥青混合料电导率提高了5～6个数量级,渗流阈值为0.2%。在复合纤维拌和分散均匀的情况下,相同掺量下,12mm长导电纤维的导电改性效果要好于6mm长导电纤维;将碳黑导电母粒与复合纤维混配掺入时,能显著提高沥青混合料的电导率,增大幅度达1个数量级。纤维沥青混合料的电导率随时间的变化呈现良好的稳定性。压敏性和温敏性试验表明,随着压力增大电导率先快后慢逐渐增大,最后趋于导电纤维的电导率,电导率随温度的升高缓慢上升,呈现正温度系数效应。导电沥青混凝土的导电行为可用导电通道和隧道效应进行分析,引进了考虑填料在基体中形成导电网络链难易程度的网络因子n,结合渗流导电理论,建立了导电沥青混合料的“海岛—网络”模型。综合分析复合导电纤维沥青混凝土中纤维分散性、力学性能和电性能指标,确定导电纤维的最佳掺量是0.2%～0.4%。更多还原

【Abstract】 Asphalt concrete is widely used in freeway, runway of airport, bridge pavement, and the roads of the city. Currently, the breakage of asphalt concrete pavement in China is still a serious problem. In order to monitor the damage of the asphalt pavement and manage the Intelligent Transportation System to prolong the service life of asphalt concrete pavement, a new multi-functional material-polyaniline compound conductive fiber blended asphalt concrete was investigated in the paper, in which the polyaniline compound conductive fiber mixed as electric conduction material. The design of the asphalt concrete was based on the SMA （Stone Mastic Asphalt） -16 discontinuous grade gradation. The paper was supported by "the research of polyaniline/polypropylene conductive fiber concretes compound materials" of the Science and Technology Funding Project of Liaoning Province and "the research of polyaniline/polypropylene electric conduction complex fiber" of the Education Departmentn of Liaoning Province Project.Preparing polyaniline/polypropylene compound conductive fiber through the in-situ polymerization synthesis and using aniline as a monomer and polypropylene fiber as a matrix. The optimal reaction condition could be gotten from the experimental results: the density of hydrochloric acid is 0.6 mol/L, the content of aniline monomer is 90 %; the density of oxidant is 0.02 g/mL; the reaction time is 2 h; the reaction temperature is below 20℃. Moreover, the polyaniline can form continuous electric conductive deposited coating on the surface of the matrix fiber as its content reaches 2.5 %, and the conductivity of the fiber can increase from 10^-13S/cm to 10^-1S/cm.The structure and the property of the polyaniline/polypropylene compound conductive fiber were examined by using infrared spectrum （FT-IR）, scanning electron microscope （SEM）, thermogravimetric analysis （TGA）, optical microscope, and tensile test. The results show that the compound conductive fiber has typical structure of sheath-core consists of black greened polyaniline electric conductive deposition as the skin and the white polypropylene matrix fiber as the core, which makes the compound fiber preferable physical mechanical property. The intensity and the elongation ratio of the electric conductive fiber are decreased but the thermal stability is enhanced after modified. The compound fiber has the good acid resistance but poor base resistance. The thermal stability of the compound fiber prepared by 4-methyl-benzene sulfonic acid （organic acid） is better than that prepared by hydrochloride acid （inorganic acid）. Moreover, the compound fiber can be re-doped by other organic or inorganic acid after freed from the adsorbed acid. Furthermore, the electric conductivity of the compound fiber decreases with the temperature increasing but hardly changed with the humidity. The adsorptive ability and therefore the content of the polyaniline, the constant of electric conduction, and the durability of the compound fiber can be enhanced by thinning the diameter, section heteromorphosis, section heteromorphosis and plasma treatment of the surface or blending with COPET of the fiber. The content of polyaniline of the fiber is 7.9 %, the constant of electric conduction is 0.17 S/cm and unchangeable for more than 6 months, and the washing times in water is more than 55 after plasma treatment of the fiber surface.The mechanical properties of the asphalt concrete mixed with and without compound fiber were examined through Marshall Method. The result show that the mechanical property of the asphalt concrete intermingled with polyaniline compound fiber was enhanced. When the fiber dispersed uniformly, the Marshall stability, the flow value, the air voids ratio, and the voids filled of the asphalt concrete increase with the content of the compound fiber increasing. On the degree of enhancing the mechanical property of the bituminous mixture, the four things rank in turn from high to low are mixed PANI/PP and PANI/PET fibers, the PANI/PP compound conductive fiber, the PANI/PET compound conductive fiber, the polypropylene fiber, and the polyester fiber. It is obviously that stability of the asphalt concrete intermingled with polyaniline compound fiber is better than that with polyaniline compound fiber, which shows the different trends comparing with the mechanical property of the conductive fiber after conduction modified.The electric conductivity of the asphalt concrete intermingled with polyaniline compound fiber is improved. The experimental results indicate that the constant electric conductivity of the asphalt concrete with the transfusion threshold of 0.2 % is increased by 5～6 power. When the compound fiber dispersed uniformly, the conductivity of the asphalt concrete modified with the fiber of 12 mm in length is better than that of 6 mm in length. Moreover, the electric conductivity of the asphalt concrete can be increased an order magnitude when the carbon black and the compound fiber mixture blended simultaneously in the asphalt concrete.The electrical conductivity of the asphalt concrete is stable over time. The examination of the susceptivities of press and temperature of the asphalt concrete indicated that the electric conductivity of samples increased with the press increasing with a degressive acceleration and finally reached the electrical conductivity of compound fiber. Moreover, the constant electrical conductivity of the asphalt concrete increased slowly with the temperature increasing, which presented a normal temperature effect. The mechanism of the electric conduction of the asphalt concrete can be explained by using electric channels and tunnel effect in which a net factor, n, which indicates the capability of conductive net formation in the concrete. Combined with the transfusion theory, a type of sea-island model is proposed.Based on the systematical analysis of the dispersivity of the compound fiber, the mechanical property, and the electric conductivity of the asphalt concrete, the optimal content of the compound fiber is 0.2～0.4 %.更多还原