Abstract: The use of traditional solvent polyurethane (PU) is likely to cause environmental pollution, which hinders the wide application of PU in functional films, finishes, foaming materials and the like. Blocked solvent-free polyurethane (SFPU), with its advantages of green, environmental protection, low energy consumption, high stability and simple operation, has become a research hotspot in the field of PU in recent years. In particular, SFPU with controllable activity can achieve efficient sealing and unsealing, which promotes the further development of PU materials. However, due to the difference in the type and structure of the blocking agent, the blocked SFPU prepolymer formed has large deflagration temperature fluctuation and easy yellowing. In addition, the escape of the small molecule blocking agent during deblocking destroys the regularity of the product structure, reducing its mechanical properties. Therefore, in recent years, in addition to studying the effect of monomer on the physicochemical properties of blocked SFPU, the researchers have been trying on the selection of sealants, and have achieved relevant results, which effectively reduce the stability of blocked SFPU materials. It unblocks the temperature. At present, the blocked SFPU can achieve complete deblocking at 120 ℃. The commonly used blocking agents are mainly alcohols, phenols, terpenes, amines and amides, active methylenes, pyrazoles and triazoles, bisulfites and the like. Among these blocking agents, the blocking agent for the alcohol structure is the earliest, the blocked prepolymer has a lo-wer activity and a higher deblocking temperature, giving the material excellent stability; although the anthraquinone blocking agent is lower. The release of the active isocyanate group at the deblocking temperature facilitates the re-extraction of the exposed isocyanate group and the chain extender, but the yellowing resistance is poor; the less toxic pyrazole and triazole sealer have nitrogen The structure of the five-membered ring is not easy to yellow. The blocked SFPU was initially prepared by a method of directly blocking the isocyanate monomer, but the method has a poor effect of extending the chain and a low film forming property. In recent years, the research work has adopted the method of sealing SFPU prepolymer, that is, synthesizing SFPU prepolymer first, and further blocking the prepolymer, ensuring high molecular weight and good film formation of the blocked SFPU. In this paper, the research progress of blocked PU is reviewed, including three types of traditional blocked solvent PU, blocked WPU and blocked SFPU. The types and synthesis of blocked PU, common blocking agent and blocked-unblocking are discussed. Reaction mechanism, factors influencing the deblocking temperature, and methods for determining the deblocking temperature. The mechanism of blocked deblocking is divided into elimination-addition mechanism and nucleophilic substitution mechanism; the factors affecting the deblocking temperature are the structure of isocyanate, the structure of the blocking agent, the reaction medium and the catalyst. At the end of this paper, the advantages and disadvantages of the current blocked SFPU are summarized. It is pointed out that solving the three difficulties of blocking agent release, high deblocking temperature and high viscosity when unsealing is the key to be solved in the application process of this technology.
Zheng Y. Journal of Chemical Education,2003(4),3(in Chinese).郑彦.化学教育,2003(4),3.2 Qin Y, Wang Q Q. China Building Materials Science & Technology,2017(1),39(in Chinese).秦颖,王强强.中国建材科技,2017(1),39.3 Lan J. Regulation of reaction progress of two component solvent-free pol-yurethan. Master’s Thesis,Xi’an University of Science and Technology, China,2015(in Chinese).兰金鹏.双组份无溶剂聚氨酯反应过程的调控研究.硕士学位论文,西安科技大学,2015.4 Li S X, Zhu L M. Polyurethane resin,Phoenix Science Press, China,1993(in Chinese).李绍雄,朱吕民.聚氨酯树脂,江苏科学技术出版社,1993.5 Zhu C C, Lv G H, Weng H Y. Chemical Propellants & Polymeric Mate-rials,2013(5),1(in Chinese).朱长春,吕国会,翁汉元.化学推进剂与高分子材料,2013(5),1.6 Kothandaraman K, Thangavel R. Journal of Applied Polymer Science,1993,47,1791.7 Guo S. Study on Synthesis, Characterization and properties of blocked isocyanate and blocked waterborne polyurethane. Ph.D. Thesis, South China University of Technology, China,2016(in Chinese).郭森.封闭型异氰酸酯及封闭型水性聚氨酯的合成、表征与性能研究.博士学位论文,华南理工大学,2016.8 Mao H, Qiang S, Yang F, et al. Journal of Applied Polymer Science,2015,132(46),42780.9 Geng Y Z. Modern water-based paint (process, formulation, application), China Petrochemical Press, China,2003(in Chinese).耿耀宗.现代水性涂料(工艺·配方·应用),中国石化出版社,2003.10 Li S W, Liu Y J. Polyurethane resin and its application, Chemical Industry Press, China,2002(in Chinese).李绍维,刘益军.聚氨酯树脂及其应用,化学工业出版社,2002.11 Tu W P. Waterborne Coating, Chemical Industry Press, China,2006(in Chinese).涂伟萍.水性涂料,化工工业出版社,2006.12 Liu Y B. Polyurethane,2006(5),15(in Chinese).刘银波.聚氨酯,2006(5),15.13 Zheng M J. Study of synthesis and modification of blocked water-borne polyurethane. Master’s Thesis, Xi’an Polytechnic University, China,2012(in Chinese).郑敏捷.封端型水性聚氨酯的合成及其改性研究.硕士学位论文,西安工程大学,2012.14 Pan Z R. Macromolecular Chemistry, Chemical Industry Press, China,2007(in Chinese).潘祖仁.高分子化学,化学工业出版社,2007.15 Cai X Y, Du Y, Ren X F. Adhesion,2012(3),81(in Chinese).蔡小燕,杜郢,任筱芳.粘接,2012(3),81.16 Yuan X L. Study on preparation of two-component solvent-free polyurethane adhesive. Master’s Thesis, Guangxi University of Science and Technology, China,2010(in Chinese).袁晓玲.无溶剂型双组分聚氨酯胶粘剂的制备与研究.硕士学位论文,广西科技大学,2010.17 Fan G D, Li A F, Li H N, et al. Journal of Safety and Environment,2012(6),18(in Chinese).樊国栋,李阿峰,李会宁,等.安全与环境学报,2012(6),18.18 Ma Y B, Wang Y F, Zhang Y H, et al. China Adhesives,2017(7),49(in Chinese).马杨豹,王逸峰,张彦华,等.中国胶粘剂,2017(7),49.19 Frisch K C, Reegen S L, Thir B. Journal of Polymer Science Part C Polymer Symposia,2007,16(4),2191. 20 Rand L, Thir B, Reegen S L, et al. Journal of Applied Polymer Science,1965,9(5),1787.21 Okuma T, Uemiya N, Ooka H. JP,2014172839-A,201422 Wicks Z W. Progress in Organic Coatings,1975,3(1),73.23 Lou C H, Gu J Y, Di M W, et al. Iranian Polymer Journal,2011,20(3),247.24 Lou C H. Synthesis and curing mechanism of curing agent of blocked isocyanate. Ph.D.Thesis,Northeast Forestry University, China,2011(in Chinese).娄春华.封闭异氰酸酯固化剂的合成与固化机理的研究.博士学位论文,东北林业大学,2011.25 Yang P F, Han Y D, Li T D. Advanced Materials Research,2010,150-151,23.26 Yang X P, Lu B. Liaoning Chemical Industry,2014(4),379(in Chinese).杨鑫鹏,陆波.辽宁化工,2014(4),379.27 Qi S Y. Guangzhou Chemical Industry,2012,40(19),72(in Chinese).祁世宇.广州化工,2012,40(19),72.28 Sang Y, Yang P F, Li T D. Chinese Chemical Letters,2013,24(11),1019.29 Nasar A S, Raghavan A, Kumar V S. Journal of Macromolecular Science-Pure and Applied Chemistry,2005,A42(3),309.30 Zhang Y Z, Hu X Y, Chen Y, et al. Adhesion,2011(10),58(in Chinese).张银钟,胡孝勇,陈耀,等.粘接,2011(10),58.31 Sankar G, Nasar A S. Journal of Applied Polymer Science,2008,109(2),1168.32 Sankar G, Sultan N A. Journal of Polymer Science Part A: Polymer Che-mistry,2007,45(8),1557.33 Regulski T, Thomas M R. Journal of Applied Polymer Science,1983,48,1003.34 Chen Y C, Wu W Y, Juang T Y, et al. Polymer Chemistry,2011,2(5),1139.35 Muramatsu I, Tanimoto Y, Kase M, et al. Progress in Organic Coatings,1993,22(1),279.36 Liao Y W. Preparation of one-component polyurethane(urea) elastomer coating and study on its properties for surface protection. Ph.D.Thesis,China Academy of Machinery Science and Technology, China,2011(in Chinese).廖有为.单组份聚氨酯(脲)弹性体涂层研制及其表面保护性能研究.博士学位论文,机械科学研究总院,2011.37 Deng Y S. Synthesis and application of aqueous polyurethane blocking agent of oximes. Master’s Thesis,Xiangtan University, China,2008(in Chinese).邓义沙.水性聚氨酯肟类封闭剂的合成与应用.硕士学位论文,湘潭大学,2008.38 Rafiemanzelat F, Abdollahi E. Journal of Applied Polymer Science,2012,123(2),1015.39 Tong S Y. Modern Paint and Finishing,2002(3),30(in Chinese).童身毅.现代涂料与涂装,2002(3),30.40 Zhang Y H. Preparation of blocking isocyanate and study on the unbloc-king. Master’s Thesis,Northeast Forestry University, China,2006(in Chinese).张彦华.封闭异氰酸酯的制备及其解封闭研究.硕士学位论文,东北林业大学,2006.41 Wang X W. Synthesis and application of the water-soluble blocked isocyanate monomer. Master’s Thesis,Hefei University of Technology, China,2010(in Chinese).王晓文.水溶性封闭型异氰酸酯单体的制备及其应用.硕士学位论文,合肥工业大学,2010.42 Zhou X D, Cai R Z, Shi Y P. Advanced Materials Research,2011,175,729.43 Wang T, Zhang H Y. Guangzhou Chemical Industry,2011,39(21),7(in Chinese).王涛,张华勇.广州化工,2011,39(21),7.44 Tassel X, Barbry D, Tighzert L. European Polymer Journal,2000,36(9),1745.45 Deng P, Cheng Y. West Leather,2012(2),39(in Chinese).邓平,程原.西部皮革,2012(2),39.46 Ge J W, Hu J Q, Chen Z S, et al. Modern Paint & Finishing,2006(3),41(in Chinese).葛俊伟,胡剑青,陈震生,等.现代涂料与涂装,2006(3),41.47 Liu Y H, Zhao H, Li G P. Isocyanate, Chemical Industry Press, China,2004(in Chinese).刘玉海,赵辉,李国平,等.异氰酸酯,化学工业出版社,2004.48 Zhu L M. Polyurethane composite, Phoenix Science Press, China,2002(in Chinese).朱吕民.聚氨酯合成材料,江苏科学技术出版社,2002.49 Delebecq E, Pascault J P, Boutevin B, et al. Chemical Reviews,2013,113(1),80.50 Zhang H L, Zhang B, Dai Z. Coatings Technology and Abstracts,2009(2),14(in Chinese).张海龙,张彪,戴震.涂料技术与文摘,2009(2),14.51 Sankar G, Yan N. Journal of Macromolecular Science, Part A,2015,52(1),47.52 Yue Y S. Study on blocking isocycanatewith substituted phenols. Ph.D. Thesis, Northeast Forestry University, China,2010(in Chinese).岳彦山.取代酚封闭异氰酸酯的研究.硕士学位论文,东北林业大学,2010.53 Petrak S, Shadurka V, Binder W H. Progress in Organic Coatings,2009,66(3),296.54 Lee J H, Lee U S, Jeong K U, et al. Polymer International,2010,59(12),1683.55 Semsarzadeh M, Navarchian A. Journal of Applied Polymer Science,2003,90(4),963.56 Vandenabeele-Trambouze O, Mion L, Garrelly L, et al. Advances in Environmental Research,2001,6(1),45.57 Blank W J, He Z, Picci M E. Polymeric Materials Science and Enginee-ring-Washington,1998,79,399.58 Whitman G M. US,2501509,1950.59 Gong Y H, Yang P F, Tao F R, et al. International Journal of Polymer Analysis and Characterization,2014,19(2),107.60 Glowińska E, Datta J. Cellulose,2015,22(4),2471.61 Wang W Q. Chemical World,2008(7),412(in Chinese).王文清.化学世界,2008(7),412.62 Wu H L. Synthesis and characterization of reproducible aqueous isocyanate micelles with low de-blocking temperature and its stability research. Master’s Thesis,Northeast Forestry University, China,2015(in Chinese).邬洪川.中低温解封闭水性异氰酸酯胶束合成、表征与稳定性研究.东北林业大学,2015.63 Lee Y M, Kim T K, Kim B K. Polymer International,1992,28,157.64 David D J, Staley B. Analytical Chemistry of Polyurethanes, High Polymer Series. XVI, Part III, Wiley-Interscience, New York, USA,1969.65 Kim B K, Lee S Y, Lee S J. Polymer International,1997,42,67.66 Hepburn C. Polyurethane Elastomers, Appl., Sci. Publishers, USA,1992,10. 67 Provder T, Neag C M, Carlson G M, et al. Analytical Calorimetry(eds. Johnson J F,Gill PS), Plenum Press, New York, USA,1984.
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