穿插法修复旧管道用聚乙烯的改性研究

【作者】 刘铁民；

【导师】 张广成；

【作者基本信息】 西北工业大学 ， 材料学， 2004， 硕士

【摘要】 穿插法修复金属旧管道通常使用管材级高密度聚乙烯(HDPE)作为塑料内衬管。其缺点是形状回复能力不够理想、耐80℃原油的腐蚀性能较差，因而影响其在输油管线上的应用。 本文通过丁腈橡胶(NBR-40)、天然橡胶(NR)、三元乙丙橡胶(EPDM)等弹性体与HDPE共混，提高了HDPE的形状回复能力。研究了两种HDPE、HDPE／不同弹性体、XLPE及HDPE／动态硫化弹性体的形状回复能力；探讨了HDPE及共混体系形状回复的机理；研究了长时间、常温和高温条件下，不同材料的耐原油腐蚀性能及机理；还研究了弹性体的含量对共混体系力学性能和流动性能的影响规律。根据材料的形状回复能力、耐原油腐蚀能力和力学性能，筛选出了穿插用的衬管材料；确定了适合于穿插法修复旧管道的工艺，并初步应用于穿插法修复旧管道的实验中。 结果表明：(1)HDPE／弹性体、XLPE、HDPE／动态硫化弹性体能够显著改善HDPE的形状回复能力；在HDPE／EPDM、HDPE／NR和HDPE／NBR三种共混体系中，HDPE／NR的形状回复能力最好，HDPE／弹性体共混体系的力学性能和流动性能随弹性体含量增加而降低；(2)LDPE耐80℃原油腐蚀性能很差，HDPE耐80℃原油腐蚀性能良好；共混体系中HDPE-2480／NBR(15％)耐80℃原油腐蚀性能良好；(3)作为穿插法修复旧管道的衬管材料，共混体系中弹性体含量以15％为宜。HDPE-2480／NBR(15％)体系适合于修复输油管；HDPE-2480／NR(15％)和HDPE-2480／EPDM(15％)适合于修复输水、输气管道；(4)在四种修复工艺中，冷缩径-冷回复的修复效果最佳。更多还原

【Abstract】 The intercrossing method in repairing old metal pipes usually uses pipe-class high density polyethylene ( HDPE ) as lining plastic-underlayer pipes. Its’weakness is that the shape recovery property is not ideal and the anticorrosion property in 80癈 crude oils is so bad that it is limited in the oil pipeline on-line application.In this thesis elastomers such as nitrile rubber (NBR-40), natural rubber (NR) and ethylene propylene diene monomer (EPDM) are blended with HDPE to improve the shape recovery properties of HDPE. The influence of different kinds of HDPE, elastomers and elastomers’ content on the shape recovery properties of blended system is studied; the shape recovery mechanism of HDPE and blended system is discussed; also the anticorrosion properties of HDPE and blended system in normal and high temperature during a long time crude oils is studied. Meanwhile we study the mechanical properties and the influent rule of the content of elastomer on blended system’s mechanical properties. According to the shape recovery properties, the anticorrosion property to crude oil and the mechanical properties we not only choose the proper underlayer material for the intercrossing method in repairing old pipe, butalso ascertain the appropriate craftwork. At last the material and the craftwork are attempted to repair a pipe .The results show that: Firstly, all of HDPE/elastomer, XLPE, HDPE/dynamic vulcanization elastomer can obviously improve the shape recovery properties of HDPE; the shape recovery properties of HDPE/NR is the best among the three kinds of blended system HDPE/EPDlvL HDPE/NR and HDPE/NBR, but the mechanical properties and flow behavior will decrease in a certain degree. Secondly, HDPE and HDPE (2480)/NBR(15%) have the better anticorrosion to hot crude oil, and the anticorrosion of LDPE is the worst; Thirdly, the content of elastomer should be about 15 wt% if the blended system is used in the intercrossing method in repairing old pipes. HDPE-2480/NBR(15%) is fit for the pipeline of crude oil transportation, HDPE-2480/NR(15%) and HDPE-2480/EPDM(15%) are fit for the pipeline of water or gas transportation; Lastly, the cold deformation- cold recovery is the best technical condition.更多还原