论文标题:聚合物结构对改性沥青性能的影响
The Influence of Polymer Structure on the Performance of Modified Asphalt
论文作者
论文导师 张玉贞,论文学位 硕士,论文专业 化学工艺
论文单位 中国石油大学,点击次数 96,论文页数 82页File Size1117K
2007-05-01论文网 http://www.lw23.com/lunwen_640671142/
modified asphalt;; polymer structure;; SBS;; LDPE
聚合物改性沥青的机理是聚合物通过吸收基质沥青中的轻组分发生溶胀,形成网络结构。该网络结构的性质和对沥青的改性效果是基质沥青性质、聚合物的性质和含量与沥青-聚合物相容性的函数,其中聚合物的结构起着重要作用。本文选取双螺杆挤出机加工改性沥青为研究对象,通过改变基质沥青种类、改性剂的种类、改性剂的添加量,制备不同的改性沥青样品,分析和表征改性沥青样品的性质。 实验结果表明,双螺杆挤出机能够将改性剂较为均匀地分散在基质沥青中,使基质沥青的各方面性质得到改善。两种基质沥青经SBS改性后,软化点升高,针入度下降,延度先升高后降低。R-SBS改性沥青的软化点、延度高于L-SBS改性沥青。 GMA-g-LDPE比LDPE更大幅度提高了基质沥青的软化点和低温延度,降低了基质沥青的温度敏感性,具有较好的高温储存稳定性。红外光谱验证了LDPE与沥青属于溶涨没有发生任何反应,而GMA所含的环氧基吸收峰消失,说明GMA-g-LDPE的环氧环与沥青中的官能团发生了反应。互穿网络的协同作用大大增加了GMA-g-LDPE与沥青的相容性,有效改善了GMA-g-LDPE改性沥青的各项性能。 与LDPE相比,MAH-g-LDPE可以大幅度提高基质沥青的软化点和针入度指数,明显改善基质沥青的高温性能和感温性能,但对基质沥青的低温性能没有改善。离析实验说明MAH-g-LDPE改性沥青的高温储存稳定性不好。红外光谱验证了MAH中羧酸酐的特征吸收峰消失,说明MAH-g-LDPE与沥青中的官能团发生了反应,但MAH-g-LDPE自身发生了严重的交联反应,导致改性沥青的低温性能和高温稳定性降低。
The structure of polymer is an important factor to the performance of modified asphalt. The polymer modified asphalts (PMA) were prepared using a twin-screw extruder. Two kinds of asphalt with different components were mixed with two SBS polymers and three PE polymers at four polymer contents. The binders were subjected to fluorescent microscopy and Fourier transform infrared (FTIR) spectroscopy besides of conventional analysis such as softening point, ductility and penetration. The results of the investigation indicated that the addition of SBS and stabilizer initiated the cross-linking reaction between SBS as well as SBS and asphalt to form a network. As a result, the performances of asphalt at both high and low temperature and stability at high temperature were improved greatly. And the performances of R-SBS PMA were superior to those of L-SBS PMA because of the particular structure of R-SBS molecule. By grafting some functional groups (GMA and MAH) to LDPE, both GMA-g-LDPE and MAH-g-LDPE improved the performance of high temperature and temperature-susceptibility compared with LDPE. However, GMA-g-LDPE also improved the performance of low temperature and stability at high temperature while MAH-g-LDPE could not because of self-crosslinking. FTIR indicated that there was no peak change when LDPE was mixed with asphalt, while the epoxy group of GMA-g-LDPE and carboxylic acid anhydride of MAH-g-LDPE disappeared.
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