Properties and Microscopic Mechanism of PAPI Type Polyurethane Modified Asphalt

Abstract

Abstract: In order to study the modification mechanism of polyurethane (PU) on asphalt, two kinds of PU prepolymers were synthesized from polymethylene polyphenyl polyisocyanate (PAPI), polyglycol adipate diol (PEA) and polytetrahydrofuran (PTMEG), which were used to prepare PU modified asphalt. The basic properties of modified asphalt were tested by penetration test, softening point test, ductility test and viscosity test, and the microstructure and reaction mechanism of modified asphalt were analyzed by fourier transform infrared spectroscopy (FTIR), atomic force microscope (AFM), thermogravimetric (TG) analysis and differential scanning calorimetry (DSC).The results show that PAPI type PU improves the high and low temperature performances of asphalt through physical and chemical reactions. The addition of PU reduces the penetration of asphalt by more than 20%, improves the softening point by more than 35%, and improves the ductility by more than 350%. Both PU modifiers significantly improve the viscosity of asphalt. PU reacts with asphalt to form PU-asphalt grafts to improve compatibility, resulting in a change in the ratio of functional groups of modified asphalt. The incorporation of PU increases the height of the bee-shaped structure in the asphalt, thereby improving the high temperature performance of the asphalt. PAPI-PEA type PU modified asphalt has better thermal stability than PAPI-PTMEG type PU modified asphalt, while PAPI-PTMEG type PU modified asphalt has a lower glass transition temperature.

Key words: polyurethane, modified asphalt, polyurethane modified asphalt, high temperature performance, thermal stability, microscopic mechanism

CLC Number:

U414

WANG Li, ZHANG Zengping, ZHU Youxin, LIU Hao, CHEN Liqi, BAN Xiaoyi. Properties and Microscopic Mechanism of PAPI Type Polyurethane Modified Asphalt[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(12): 4158-4166.

References

[1] 山西省化工研究所.聚氨酯弹性体手册[M].第2版.北京:化学工业出版社,2012.
Shanxi Institute of Chemical Industry. Handbook of polyurethane elastomer[M]. 2nd ed. Beijing: Chemical Industry Press, 2012 (in Chinese).
[2] AKINDOYO J O, BEG M D H, GHAZALI S, et al. Polyurethane types, synthesis and applications: a review[J]. RSC Advances, 2016, 6(115): 114453-114482.
[3] CONG L, YANG F, GUO G H, et al. The use of polyurethane for asphalt pavement engineering applications: a state-of-the-art review[J]. Construction and Building Materials, 2019, 225: 1012-1025.
[4] CARRERA V, GARCIA-MORALES M, PARTAL P, et al. Novel bitumen/isocyanate-based reactive polymer formulations for the paving industry[J]. Rheologica Acta, 2010, 49(6): 563-572.
[5] YU R E, ZHU X J, ZHANG M R, et al. Investigation on the short-term aging-resistance of thermoplastic polyurethane-modified asphalt binders[J]. Polymers, 2018, 10(11): 1189.
[6] FANG J M, TU J S. Effect of ultraviolet (UV) aging on rheology properties and microstructure of polyurethane (PU) modified asphalt[J]. Materials Research Express, 2019, 6(12): 125318.
[7] 孙敏,郑木莲,毕玉峰,等.聚氨酯改性沥青改性机理和性能[J].交通运输工程学报,2019,19(2):49-58.
SUN M, ZHENG M L, BI Y F, et al. Modification mechanism and performance of polyurethane modified asphalt[J]. Journal of Traffic and Transportation Engineering, 2019, 19(2): 49-58 (in Chinese).
[8] ZHANG Z P, SUN J, JIA M, et al. Study on a thermosetting polyurethane modified asphalt suitable for bridge deck pavements: formula and properties[J]. Construction and Building Materials, 2020, 241: 118122.
[9] KAZEMI M, GOLI A, NASIMIFAR M. Evaluation of the self-healing performance of polyurethane-modified bitumen using bitumen bond strength (BBS) test and CT scan[J]. International Journal of Pavement Research and Technology, 2021, 14(2): 168-173.
[10] 交通部公路科学研究所.公路工程沥青及沥青混合料试验规程:JTG E20—2011[S].北京:人民交通出版社,2011.
Research Institute of Highway Ministry of Transportation. Standard test methods of bitumen and bituminous mixtures for highway engineering: JTG E20—2011[S]. Beijing: China Communications Press, 2011 (in Chinese).
[11] LUO S, TIAN J H, LIU Z M, et al. Rapid determination of styrene-butadiene-styrene (SBS) content in modified asphalt based on Fourier transform infrared (FTIR) spectrometer and linear regression analysis[J]. Measurement, 2020, 151: 107204.
[12] DAS P K, BAAJ H, TIGHE S, et al. Atomic force microscopy to investigate asphalt binders: a state-of-the-art review[J]. Road Materials and Pavement Design, 2016, 17(3): 693-718.
[13] 王冰花,陈金龙,张彬.原子力显微镜在高分子表征中的应用[J].高分子学报,2021,52(10):1406-1420.
WANG B H, CHEN J L, ZHANG B. Application of atomic force microscopy in polymer characterization[J]. Acta Polymerica Sinica, 2021, 52(10): 1406-1420 (in Chinese).
[14] POLACCO G, FILIPPI S, MERUSI F, et al. A review of the fundamentals of polymer-modified asphalts: asphalt/polymer interactions and principles of compatibility[J]. Advances in Colloid and Interface Science, 2015, 224: 72-112.
[15] 曹雪娟,唐伯明.热分析动力学研究环氧沥青混凝土的固化条件[J].公路交通科技,2008,25(7):17-20.
CAO X J, TANG B M. Study on cure reaction condition of epoxy asphalt concrete by thermal analysis kinetics[J]. Journal of Highway and Transportation Research and Development, 2008, 25(7): 17-20 (in Chinese).
[16] JIN X, GUO N S, YOU Z P, et al. Rheological properties and micro-characteristics of polyurethane composite modified asphalt[J]. Construction and Building Materials, 2020, 234: 117395.
[17] GUNAY T, TOMKOVIC T, HATZIKIRIAKOS S G. Thermorheological properties of asphalt binders[J]. The Canadian Journal of Chemical Engineering, 2020, 98(8): 1803-1814.