Synthesis and characterization of non-ionic and anionic two-component aromatic waterborne polyurethane

2018 ◽  
Vol 47 (4) ◽  
pp. 290-299 ◽  
Author(s):  
Sainan Zhang ◽  
Xiankai Jiang

Purpose The purpose of this paper is to synthesize and characterize a series of two-component aromatic waterborne polyurethane (2K-WPU) which is composed of non-ionic and anionic polyisocyanate aqueous dispersion and polyurethane polyol aqueous dispersion. Design/methodology/approach The polyisocyanate aqueous dispersion was synthesized through non-ionic and anionic hydrophilic modification procedures. The values of the hydrogen bonding index (HBI) and molecule structures of WPU were obtained by Fourier transform infrared (FTIR). The thermal, mechanical and water resistance properties of 2K-WPU films were investigated. Findings The appearance of non-ionic polyisocyanate aqueous dispersion and anionic polyisocyanate aqueous dispersion was colorless translucent pan blue and yellow opaque emulsions, respectively. FTIR not only showed that 2K-WPU was obtained from the polymerization of polyisocyanate component and polyhydroxy component by polymerization but also showed that the content of hydrogen bondings of anionic 2K-WPU (WPU 2) was higher than non-ionic 2K-WPU (WPU 1). The glass-transition temperature (Tg), storage modulus and water resistance of WPU 2 were higher than WPU1, whereas the thermal stability of WPU1 was better than WPU 2. Practical implications The investigation established a method to prepare a series of 2K-WPU which was composed of non-ionic or anionic polyisocyanate aqueous dispersion and polyurethane polyol aqueous dispersion. The prepared 2K-WPU film could be applied as substrate resin material in the field of waterborne coating. Originality/value The paper established a method to synthesize a series of 2K-WPU. The effect of HBI value and the molecule structure of soft segment on the thermal stability, mechanical and water resistance properties of 2K-WPU films were studied.

2018 ◽  
Vol 47 (4) ◽  
pp. 315-322 ◽  
Author(s):  
Jizhi Zhang ◽  
Xiankai Jiang

Purpose The purpose of this paper is to synthesize and characterize a series of alicyclic two-component waterborne polyurethane (2K-WPU) which is composed of non-ionic polyisocyanate aqueous dispersion and hydroxyl aqueous dispersion. Design/methodology/approach The appearances of aqueous dispersions and 2K-WPU films were observed by photographs. The micromorphology of alicyclic polyisocyanate aqueous dispersion was examined by scanning electron microscopy (SEM). The molecule structures of WPU were studied by Fourier transform infrared (FTIR). The effect of NCO:OH molar ratio of two components and trimethylolpropane (TMP) content on the thermal stability, mechanical and water resistance properties of 2K-WPU films was studied. Findings It was found by SEM that alicyclic polyisocyanate particles in aqueous dispersion showed a kind of spherical particle appearance, in which hydrophobic polyisocyanate was encapsulated by hydrophilic ether linkages segment. FTIR showed that WPU was polymerized through mixture of polyisocyanate component and hydroxyl component and increasing NCO:OH molar ratio of two components from 1.1:1 to 1.5:1 had increased the content of urea, urethane and allophanate of 2K-WPU films. Increasing NCO:OH molar ratio had improved the mechanical and thermal properties of the 2K-WPU film, but the water resistance of the 2K-WPU film increased first and then weakened. Increasing TMP contents from 1 to 0.75 mol for 1:5 system had improved the mechanical, thermal and water resistance properties of the 2K-WPU film. Practical implications The investigation established a method to prepare alicyclic 2K-WPU which is composed of non-ionic polyisocyanate aqueous dispersion and hydroxyl aqueous dispersion. The prepared 2K-WPU film could be applied in the field of waterborne surface coating, e.g. textile, wood and synthetic leather surfaces (Hasan et al., 2017; Akindoyo et al., 2016). Originality/value The paper established a method to synthesize alicyclic two-component 2K-WPU. The effect of NCO:OH molar ratio and TMP content on the thermal stability, mechanical and water resistance properties of 2K-WPU films were studied.


Author(s):  
Chenhan Zhuang ◽  
Weilan Xue ◽  
Zuoxiang Zeng

Aqueous polyurethane emulsion was prepared with diphenylmethane diisocyanate (MDI), polybutylene adipate diol (PBA-1000) as main raw materials and 2, 2-dihydroxymethyl propionic acid (DMPA) as hydrophilic chain extender. On this basis, epoxy resin E-44 was introduced to modify the polyurethane prepolymer, and epoxy resin modified waterborne polyurethane emulsion was obtained. In order to obtain better performance waterborne polyurethane, the effect of DMPA content、the amount of epoxy resin added and modification method on the properties of polyurethane was discussed. The results show that when the DMPA content is 4wt%, the overall performance of the emulsion and the film is the best. And the addition of epoxy resin significantly improves the water resistance, solvent resistance and tensile strength of the waterborne polyurethane film, and its hardness and thermal stability are also improved to a certain extent. When the amount of epoxy resin added is 8wt%, the storage stability decreases significantly, the suitable amount of epoxy resin added is 6wt%. The overall performance of the film obtained by chemical modification is better than that of physical modification.


2016 ◽  
Vol 852 ◽  
pp. 1025-1028 ◽  
Author(s):  
Xia Wang ◽  
Jiao Jiao Hu ◽  
Ying Li

Thermosetting fluorinated polyurethane coating was prepared by using fluorinated polyether polyol (FPO) as the soft segment, 4,4`-diphenylmethane diisocyanate (MDI) as the hard segment, TEA as crosslinking agent. The structure ofthermosetting fluorinated polyurethane coating was confirmed by the use of Fourier transform infrared spectroscopy (FTIR).The FPU film’s surface property was investigated by contact angle (CA),water resistance and anti-corrosion resistance measurements. The results indicated that the surface of fluorinated polyurethanes was significantly enriched with fluorine groups. The water resistance of thermosetting FPU coating was evidently better than thermoplastic FPU coating. It was also found that the surface enrichment of fluorine atoms made the fluorinated polyurethane coating had outstanding anti-corrosion resistance.


2009 ◽  
Vol 79-82 ◽  
pp. 1055-1058
Author(s):  
Sui Lian Luo ◽  
Chao Dong Liu ◽  
Guo Fei Gong ◽  
Hei Ping Lai ◽  
Wen Zhong Kong

In this work, PDMS modified PU was synthesized using two-stage method to improve water resistance and weather resistance in the waterborne polyurethane was investigated. It was found that the absorbed water content decreased with increasing PDMS content in polyurethane. It was also found that PDMS modified polyurethane had better solvent resistance than unmodified polyurethane. The structure incorporated the PDMS into the soft segment of polyurethane chains was confirmed by FTIR. The phase separation increased by increasing PDMS content and was confirmed by DSC. The particle size of the dispersions increased and tensile strength and hardness decreased with the increase of PDMS content. Furthermore, with the improved water resistance and elongation, it was hoped that the modified polyurethane could be used as wood coatings superior to the solvent-borne systems.


2015 ◽  
Vol 132 (45) ◽  
pp. n/a-n/a ◽  
Author(s):  
Changqing Fang ◽  
Wanqing Lei ◽  
Xing Zhou ◽  
Qian Yu ◽  
Youliang Cheng

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 865 ◽  
Author(s):  
Yifu Zhang ◽  
Wenkai Bei ◽  
Zhiyong Qin

The soap-free emulsion of vinyl acetate (VAc)/butyl acrylate (BA) copolymer was prepared by a semi-continuous and pre-emulsification polymerization method, using ammonium sulfate allyloxy nonylphenoxy poly(ethyleneoxy) (10) ether (DNS-86) as a reactive emulsifier. The effects of DNS-86 on the stability of the emulsion and the properties of the latex film were investigated. The infrared spectrum, thermal stability, glass transition temperature and micromorphology of latex were also studied. The results showed that the emulsion had the best stability and the conversion rate reached a maximum of 98.46% when the DNS-86 amount was 4 wt % of the total amount of monomers. Compared with the PVAc latex synthesized with octylphenol polyoxyethylene ether (10) (OP-10), the latex prepared with DNS-86 has higher thermal stability and ionic stability, whereas the latex film has better water resistance.


2016 ◽  
Vol 68 (5) ◽  
pp. 611-616 ◽  
Author(s):  
Zujian Shen ◽  
Fei Geng ◽  
Xinxin Fan ◽  
Zhichen Shen ◽  
Haiyan Wang

Purpose This paper aims to investigate and prepare the composite polyurea greases with excellent thermal stability and tribological properties. Design/methodology/approach In this paper, composite Ba-based (Ba, barium) tetra-polyurea lubricating greases were prepared with two different methods: mixing Ba-based gelatinizer and tetra-polyurea gelatinizer by a physical method; and introducing barium carboxylate into tetra-polyurea molecules by a chemical method. The properties of the products, such as heat stability, water resistance and friction performance, were analyzed with thermogravimetry, water-resistance test and four-ball friction test. Findings The results indicated that the products obtained by chemically introducing barium carboxylate into tetra-urea molecules showed better elevated temperature tribological properties, and the disadvantages of the polyurea greases with high temperature hardening were also obviously improved. The cone penetration rate at 180°C for 24 h is only 3 per cent. The friction coefficient can be decreased to 0.44 and the last non-seizure load value was increased from 560 N to 1,120 N without any other additives. Originality/value The research is significant because the prepared composite grease showed excellent performances, such as the outstanding thermal stability, water resistance and excellent extreme pressure and anti-wear properties, which may be widely applied in steel, metallurgy, bearings and other industrial fields.


2014 ◽  
Vol 513-517 ◽  
pp. 251-254 ◽  
Author(s):  
Zheng Xiang Wang ◽  
Ji Tong Yuan ◽  
Qi Long Liu ◽  
Xi Mei Xiao ◽  
Yun Hua Li ◽  
...  

A novel waterborne polyurethane (WPU) modified by tung oil was prepared with 2,4-tolylene diisocyanate, polyethylene glycol, dimethylol propinic acid, 1,4-butanedilo as main materials via acetone process. The structure of WPU molecule was characterized by FT-IR. Adhesive behavior for non-polar and/or low surface energy soft packing films was studied. Water resistance of films were evaluated by water contact angle and water uptake and thermal properties determined by thermal analysis instruments. The results show that the modified WPU films have good water and heat resistance. Both of modified WPUs or not have good adherence on BOPP films.


2014 ◽  
Vol 936 ◽  
pp. 58-62 ◽  
Author(s):  
Cheng Shu Xu ◽  
Cheng Cheng Tian ◽  
Wei Dong Zhang ◽  
Jian Wei Xing ◽  
Zai Sheng Cai ◽  
...  

Different kinds of anionic polyhydric alcohols water-borne polyurethane (WPU) emulsion and films were prepared by separately taking polypropylene carbonate polyol (PPC), polyethylene-1,4-buthylene adipate glycol (PBA) and polytetramethylene ether glycol (PTMG) with the same molecular weight as soft segment. Their structure and properties were characterized with Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), rigidity, adhesive power, contact angle and water absorption. Comparing their properties, it was found that the rigidity, adhesive power and water resistance of PPC WPU were similar to those of PBA WPU.


2021 ◽  
Author(s):  
Guangfeng Wu ◽  
Xin Song ◽  
ZhiHui Yang ◽  
Ying Chun Li ◽  
HuiXuan Zhang

Abstract Polyester diol PCL and PBA, polyether diol PTMG and polycarbonate diol PCDL were used as components of WPU soft segment, respectively. Polyether PTMG-WPU has the worst hydrolytic property and the highest thermal stability. The maximum degradation rate temperature Tmax is 407.8°C, the water contact angle reaches 89.5°. Traditional polyester PCL-WPU shows the strongest hydrolysis performance, the smallest water contact angle, only 71.7°, the water absorption rate of 72 hours at room temperature is as high as 26.7%. However, the thermal stability of PCL-WPU is lower, the soft segment Tg is -52.3°C, and Tmax is only 333.7°C, but the mechanical propertie of which is the best, the tensile strength is 58.3 MPa, and the elongation at break reaches 857.9%. The most important thing is that the structure of polyester PCL-WPU is more easily destroyed by lipase and water molecules. The acidic products produced after hydrolysis will further promote the degradation of polyester. Therefore, compared with other WPUs, PCL -WPU has the best biodegradability and the most obvious degradation effect under the same conditions. The degradation rate of PTMG-WPU after 30 days of degradation in 0.6% lipase PBS buffer solution and soil was only 4.2% and 2.3%, while the highest degradation rate of traditional polyester PCL-WPU reached 41.7% and 32.0%, respectively. In addition, polycarbonate PCDL-WPU has the highest hardness, reaching 95.5 HD. But its other performances are lower than PCl-WPU.


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