UV固化水性聚氨酯丙烯酸酯的合成及性能研究

以马来松香乙二醇酯(MRE,自制)为亲水剂,聚乙二醇(PEG1000)、甲苯-2,4-二异氰酸酯(TDI)为原料,丙烯酸羟乙酯(HEA)为封端剂,采用自乳化方式,合成了UV固化水性聚氨酯丙烯酸酯分散体(MREPUA)。考察了MRE加入量对MREPUA乳液及其涂膜力学性能和吸水率的影响,采用红外光谱及TG对涂膜UV固化程度及热稳定性进行了研究。结果表明,加入MRE的质量分数为7%时,涂膜具有较好的力学性能及良好的耐水性、耐热性。     

聚酯型水性聚氨酯的合成和性能研究

以甲苯二异氰酸酯(TDI)、聚酯二元醇、二羟甲基丙酸等为主要原料合成了聚酯型水性聚氨酯乳液。研究了三羟甲基丙烷(TMP),二羟甲基丙酸(DMPA),异氰酸酯基与羟基物质的量比(n/n)等对水性聚氨酯耐水性能、稳定性以及力学性能等的影响。结果表明,当n/n为NCO OH NCO OH2,DMPA含量为6%,TMP加入量0.6%,水性聚氨酯性能最佳。     

Preparation and photochromic properties of waterborne polyurethane containing spirooxazine groups

Two novel photochromic spirooxazines, SO 1 and SO 3, were successfully prepared and characterized by Fourier transform infrared spectroscopy (FTIR), ¹H-NMR, and mass spectrometry with electrospray ionization (ESI-MS). SO 1 was doped and grafted with waterborne polyurethane (WPU) to afford D₁-WPU and G₁-WPU. D₃-WPU was prepared by doping SO 3 with waterborne polyurethane. FTIR spectra indicated that SO 1 was grafted onto waterborne polyurethane successfully. Scanning electron microscopy proved that spirooxazines of D-WPU can be effectively dispersed in a waterborne polyurethane matrix, and spirooxazines of G-WPU are evenly distributed in the copolymer. The results showed that the light transmittance of modified waterborne polyurethane films decreased compared with pure waterborne polyurethane films, but the water resistance and tensile strength were better. Ultraviolet–visible spectra demonstrated that the thermal stability of spirooxazine derivatives improved significantly after being modified. The fading rate constant of the D₃-WPU film (k = 0.0079 s^-1) during the discoloration process decreased 9.77 times in contrast to SO 3 in ethanol, which showed that the thermal stability of spirooxazine in WPU film was obviously enhanced. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47067.     

Preparation of waterborne polyurethane adhesives based on macromolecular-diols containing different diisocyanate

ABSTRACT

Three different macromolecular diols were synthesized by the reaction of Poly(1,4-butanediol adipate) diol (PBA) and diisocyanate (Isophorone diisocyanate (IPDI), Hexamethylene diisocyanate (HDI) and Methylene-bis(4-cyclohexylisocyanate)(HMDI)) at the ratio of 2:1. Based on these macromolecular diols, waterborne polyurethane (WPU) adhesives were prepared. The structure and molecular weights of the WPU were characterized by Nuclear magnetic resonance spectroscopy (¹H NMR), Fourier Transform Infrared Spectroscopy (FTIR) and Gel permeation chromatography (GPC) respectively. Furthermore, the hydrogen bonding interaction of WPU were analyzed by the deconvolution FTIR spectra. The results showed that the hydrogen bonded NH was increased when carbamate was in the soft segment. The crystallinity of WPU was tested by X-ray diffraction (XRD) and Differential scanning calorimetry (DSC). The results showed that the crystallinity of WPU2 (HDI) and WPU3 (HMDI) were enhanced, especially for WPU2. Meanwhile, the Tg,s as well as the mechanical strength, storage modulus, the contact angle and thermo-stability were increased with the introduced carbamate into soft segment. The T-peel tests of plasticized PVC/WPU/plasticized PVC joints and lap-shear tests of wood/WPU adhesive/wood joints were carried out. The results indicated that the carbamate in the soft segment could significantly enhance the adhesion of WPU at an appropriate activation temperature.     

不同固含量对水性聚氨酯性能的影响

以异佛尔酮二异氰酸酯(IPDI)、聚己二酸丁二醇酯(PBA)为主要原料合成了不同固含量的水性聚氨酯乳液(WPU)。红外光谱表征了WPU的结构,并探讨了WPU的固含量对乳液粒径和胶膜力学性能、热性能及其微观结构的影响。结果表明,随着固含量的增加,胶膜拉伸强度降低,断裂伸长率升高;且固含量低的WPU乳液粒径分布集中,胶膜平整,固含量高的则反之;此外,不同固含量的WPU的热性能也有一定的差别,随着固含量的增加,胶膜的最大分解速率有所降低。     

不同固含量对水性聚氨酯性能的影响

以异佛尔酮二异氰酸酯(IPDI)、聚己二酸丁二醇酯(PBA)为主要原料合成了不同固含量的水性聚氨酯乳液(WPU)。红外光谱表征了WPU的结构,并探讨了WPU的固含量对乳液粒径和胶膜力学性能、热性能及其微观结构的影响。结果表明,随着固含量的增加,胶膜拉伸强度降低,断裂伸长率升高;且固含量低的WPU乳液粒径分布集中,胶膜平整,固含量高的则反之;此外,不同固含量的WPU的热性能也有一定的差别,随着固含量的增加,胶膜的最大分解速率有所降低。     

多官能度水性光敏聚氨酯丙烯酸酯的合成及性能研究

用异佛尔酮二异氰酸酯(IPDI)、丙三醇、聚四氢呋喃醚二醇(PTMG)、甲基丙烯酸羟乙酯(DMPA)、季戊四醇三丙烯酸酯(PETA)等原料合成了具有高交联度的多官能度紫外光固化聚氨酯丙烯酸酯(PUA)水乳液。采用国标GB12009.4—89,FT-IR,13C NMR,DMA,AFM等方法对PUA预聚体合成过程和聚合物乳液(涂膜)进行了测试和表征,考察了n(IPDI)∶n(HO—OH)∶n(丙三醇)、DMPA质量分数、pH值等对乳液及涂膜性能的影响。结果表明,随着丙三醇质量分数增大,PUA光固化速率、耐溶剂性、膜硬度提高、吸水率降低;随着DMPA质量分数的增加,PUA涂膜硬度、吸水率增强,乳胶粒径越来越小;随着中和度增大,乳液逐渐由云雾状趋向透明,粘度下降。当n(IPDI)∶n(HO—OH)∶n(丙三醇)=9∶6∶1,w(丙三醇)=2%左右,DMPA质量分数为4.6%,中和度为90%时,乳液储存稳定(30 d),涂膜光固化速率达到7 s,附着力为1,硬度为3 H,耐水性、耐化学品性更佳。     

Preparation and mechanical properties of waterborne polyurethane/carbon nanotube composites

Waterborne polyurethane (WBPU) and multiwalled carbon nanotubes (CNTs) composite films with 0–4.0 wt% CNTs were prepared by ultrasonic dispersion of carboxylic acid‐functionalized CNTs in WBPU followed by emulsion casting process. The elongations at break of the WBPU/CNTs composites increase with the incorporation of CNTs. The tensile strength and crystallinity of the nanocomposite films with lower CNTs contents (<2 wt%) increase obviously; while the tensile strengths of the composites with more CNTs (≥2 wt%) decrease, in contrast to the pure PU film. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations indicated that the CNTs are uniformly dispersed in the composites incorporated with lower CNTs contents (≤1.5 wt%). However, aggregation of CNTs increased with increasing CNTs content in the WBPU/CNTs composites, causing the macrophase separation. The dispersion state of the CNTs affects the crystallinity of the PU matrix and the phase separation of the composites, which are two key factors to influence the mechanical properties of the WBPU/CNTs composites. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

不同软链段对水性聚氨酯性能的影响

以低聚物多元醇、IPDI(异佛尔酮二异氰酸酯)、亲水扩链剂DMPA(2,2-二羟甲基丙酸)和成盐剂三乙胺为主要原料,合成一组软段成分不同的水性聚氨酯乳液。通过测定水性聚氨酯乳液的固含、黏度、结构,以及水性聚氨酯胶膜的耐水性、力学性能、T型剥离强度等,对比了不同类型软段对乳液及胶膜性能的影响。研究结果表明:由含6个碳的聚酯多元醇为软段合成的水性聚氨酯的黏度、耐水性、机械强度、T型剥离强度等数据较好。     

Effect of annealing on the properties of waterborne polyurethane adhesive containing urethane-based thickener

Different amounts of hydrophobically modified ethoxylated urethane-based thickener (HEUR) were added to improve the rheology of waterborne polyurethane adhesives. The thickened solid adhesive films were thermally annealed and characterised by IR spectroscopy, plate–plate rheology, dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Hydrogen bonds played a key role in the thickening mechanism of polyurethane dispersions containing urethane-based thickener, along with ionic adsorption and micelles formation between hydrophobic groups. The adhesion properties were measured from T-peel test of leather/polyurethane adhesive/vulcanised styrene-butadiene rubber joints. Optimal results were obtained when water in the waterborne polyurethane adhesive (just before joint formation) was removed under open air, while forced air drying impeded the complete removal of water. On the other hand, the thermal annealing did not greatly affect the rheological and thermal properties of the thickened polyurethanes.     

原料及合成工艺对水性聚氨酯性能的影响

用不同聚醚以及不同的合成工艺制备了性能不同的水性聚氨酯乳液,研究了原料以及合成工艺对乳液和胶膜性能的影响。结果表明:用四氢呋喃-氧化丙烯共聚二醇制备的WPU性能比用聚氧化丙烯二醇制备的WPU的综合力学性能好,并且在分散的同时进行中和以及分散时将水加入到预聚体中进行乳化所得到的乳液比较稳定,而且两步法较一步法制的乳液分散性好,但胶膜力学性能方面,一步法好。     

Effects of polyaminosiloxane on the structure and properties of modified waterborne polyurethane

A waterborne polyurethane (WPU) prepolymer was synthesized with poly(tetramethylene glycol) to form the soft segment, dimethylolpropionic acid as a hydrophilic chain extender, and isophorone diisocyanate. Moreover, the graft and block copolymer emulsification of WPU–polysiloxane and their films was carried out through reactions between the WPU prepolymer, aminoethyl aminopropyl dimethicone (AEAPS), and a linear polyether-blocked amino silicone (LEPS), respectively. The properties of the structure and formed films of the WPU were characterized with Fourier transform infrared spectrometry, gel permeation chromatography, X-ray diffraction, thermogravimetric analysis, dynamic thermomechanical analysis, and X-ray photoelectron spectroscopy; the measurement of the water contact angle; the testing of the water absorption; and so on. The WPU–polysiloxane emulsion showed a high stability, and the molecular weight of WPU increased. Moreover, the glass-transition temperature (T_g) of the soft segment of polysiloxane that was incorporated into the WPU shifted to a lower temperature range, whereas the T_g of the hard segment shifted to a higher temperature range, and the crystallinity of the WPU–polysiloxane film was reduced. There was a greater degree of crosslinking and accumulation of polysiloxane segments on the surface of the WPU emulsion that was modified with AEAPS in comparison to the LEPS-modified WPU emulsion. Therefore, the water resistance of the AEAPS-modified WPU was higher than that of the LEPS-modified WPU. The rigidity and elasticity of the WPU–polysiloxane film improved, whereas its tensile strength did not change much after AEAPS was used. However, this was not true after LEPS was used, as the tensile strength decreased significantly. Nevertheless, the flexibility and plasticity of the WPU–polysiloxane film were enhanced after LEPS was used. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47226.     

Structure–properties relationship of starch/waterborne polyurethane composites

The blend materials from waterborne polyurethane (WPU)/starch (ST) with different contents (10–90 wt %) were satisfactorily prepared by using the solution casting method. Their miscibility, structure, and properties were investigated by wide‐angle X‐ray diffraction (WAXD), scanning electron microscope (SEM), different scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), and the tensile tests, respectively. The results indicated that tensile strength of composite materials not only depended on the starch content, but also related to the microstructure of WPU. The sample WPU2 (1.75 of NCO/OH molar ratio) exhibited hard‐segment order, but WPU1 (1.25 of NCO/OH molar ratio) had no hard‐segment order. The appropriate starch filled into WPU not only decreased the ordered region of soft‐segment matrix, but also hindered the formation of hard‐segment ordered structure. The blend material from 80 wt % WPU1 and 20 wt % starch exhibited better tensile strength (27 MPa), elongation at break (949%), and toughness than others. With an increase of starch content, the WPU matrix with dispersed starch in the blends transited to dual‐phase continuity and then to starch matrix with dispersed WPU. The results suggested that a certain extent of miscibility existed between WPU and starch in the blend materials on the whole composition ratio. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3325–3332, 2003     

Characterization of waterborne polyurethane adhesives containing different amounts of ionic groups

Waterborne polyurethane adhesives are an interesting alternative to the current solvent-based polyurethane adhesives used in footwear industry. In this study, different aqueous polyurethane dispersions were prepared by using the prepolymer mixing process. The ionic groups content in the polyurethane ionomer structure was varied by changing the amount (5 and 8 wt% (with respect to the prepolymer weight) of the internal emulsifier—dimethylolpropionic acid (DMPA). The decrease in the DMPA content slightly increased the particle size in number due to the decrease in both the hydrophilicity of the polyurethane ionomer, and the electrolytic stability of the aqueous polyurethane dispersion. Furthermore, the lower the DMPA amount, the lower the hard segment content in the ionomer and the higher the crystallinity of the polyurethane; however, the resistance to flow under temperature (i.e. thermoplasticity) was reduced. The resistance to thermal degradation of the polyurethane ionomer increased by decreasing the DMPA content due to the lower hard segment content. Finally, high initial adhesive strength was obtained and the adhesion to PVC increased as the DMPA content in the polyurethane ionomer decreased.     

The effects of silver nitrate on the structure and properties of polyurethanes containing pyridyl units

In this study, 2,6-pyridinedimethanol was used as a chain extender to synthesize a new polyurethane, PDM-PU. Further, various amounts of silver nitrate were incorporated to produce PDM-PU/AgNO₃ complexes. FT-IR and UV–Vis analyses confirm the formation of complex in the PDM-PU/AgNO₃. DSC and DMA results show that the glass transition temperature (T _g), dynamic T _g and storage modulus at 25 °C of the PDM-PU/AgNO₃ complexes increase with increasing AgNO₃ content. This is due to the formation of complex structure that can restrict the segmental motion of polymer chains. The TGA and stress–strain test results show that the thermal decomposition temperature, tensile strength and elongation at break increase with the AgNO₃ content initially. Then, they decrease inversely. This indicates that the formation of complex structure raises these properties when the AgNO₃ content is below certain value. But as more coordinate bonds were formed, the specimens become brittle. In addition, the crosslink effect caused by coordinate bonds inhibits the dissolution of polymer chains and thereby reduces the swelling degree of the complexes in solvent. Furthermore, AgNO₃ imparts antibacterial activity against S. aureus and K. pneumoniae to the complexes     

Structure and properties of waterborne polyurethane adhesives obtained by different methods

The structure and properties of two aqueous polyurethane dispersions prepared by two different methods (acetone method and prepolymer mixing method) were compared. The aqueous polyurethane dispersion obtained by the acetone method (PU-AP) showed a narrower particle size distribution than that of the sample obtained by the prepolymer mixing method (PU-PMP), because the use of an organic solvent in the synthesis produced a lower prepolymer viscosity, thus facilitating dispersion in water. PU-PMP showed more crosslinked structure than PU-AP, and, consequently, PU-PMP had higher elastic (G') and viscous (G") moduli and also a higher cross-over temperature between these moduli in the rheological curves. On the other hand, the lower degree of crosslinking in PU-AP facilitated polyurethane crystallinity. Thermal degradation resistance was similar and both polyurethanes showed similar decomposition patterns. Immediate adhesion of the aqueous poly-urethane dispersions to PVC was low, although it was somewhat higher for the joint produced with PU-AP. The adhesive strength increased by increasing the time after joint formation, and after 72 h was similar for the two adhesives.     

Mechanical and thermal properties of waterborne epoxy composites containing cellulose nanocrystals

Cellulose nanocrystals (CNCs) are reinforcing fillers of emerging interest for polymers due to their high modulus and potential for sustainable production. In this study, CNC-based composites with a waterborne epoxy resin matrix were prepared and characterized to determine morphology, water content, and thermal and mechanical properties. While some CNC aggregation was observed, the glass transition temperature (T_g) and modulus for the composites increased with increasing CNC content. Relative to neat epoxy, at 15 wt.% CNC the storage modulus increased by 100%, the T_g increased from 66.5 °C to 75.5 °C, and tensile strength increased from 40 MPa to 60 MPa, suggesting good adhesion between epoxy and CNC surfaces exposed to the matrix. Additionally, no additional water content resulting from CNC addition were observed. These results provide evidence that CNCs can improve thermomechanical performance of waterborne epoxy polymers and that they are promising as reinforcing fillers in structural materials and coatings.     

Preparation and properties of functionalized graphene/waterborne polyurethane composites with highly hydrophobic

The long‐chain functionalized graphene nanoplatelets (FGN) were functionalized by isophorone diisocyanate and then octadecylamine, the graphene functionalized/waterborne polyurethane (WPU) composites were prepared by solution mixture. The results showed that the FGN achieved good dispersion with exfoliated and intercalated nanostructure and strong interfacial adhesion with WPU, which made the nano–composites have a significant enhancement of thermal stability and mechanical properties at low FGN loadings. With 1.5% of FGN added, the tensile strength of the composites reached the maximum of 17 MPa, which improved by 41.6%, the water absorption of the composites is only 6.7%. With the incorporation of 2 wt % FGN, and the static contact angle of the composites reached to about 120°, showing the high hydrophobicity. At the same time, the volume resistivity of the composites was changed from 2.34 × 10¹² Ω·cm to 3.77 × 10⁹ Ω·cm. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42005.     

Mechanical properties and biodegradability of crosslinked soy protein isolate/waterborne polyurethane composites

With anionic waterborne polyurethane (WPU) as a plasticizer and ethylene glycol diglycidyl ether (EGDE) as a crosslinker, we successfully prepared crosslinked soy protein isolate (SPI) plastics. Anionic WPU was mixed with SPI and EGDE in an aqueous dispersion at room temperature. The mixed aqueous dispersion was cast and cured, and the obtained material was pickled and hot‐pressed to produce the crosslinked SPI/WPU sheets. The resulting sheets containing about 60 wt % SPI were characterized with infrared spectroscopy, scanning electron microscopy, atomic force microscopy, dynamic mechanical analysis, and tensile testing, and biodegradation testing of the sheets was performed in a mineral salt medium containing microorganisms. The results revealed that the crosslinked SPI/WPU plastics with EGDE concentrations of 2–4 wt % possessed high miscibility, good mechanical properties, and water resistivity. In addition, the crosslinked sheets could be biodegraded, and the half‐life of the biodegradation for a sheet crosslinked with 3 wt % EGDE was calculated to be less than 1 month. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 465–473, 2005