Dynamic colloidal processes in waterborne two-component polyurethanes and their effects on solution and film morphology

Otts, Daniel B.; Pereira, Kevin J.; Jarret, William L.; Urban, Marek W.

doi:10.1016/j.polymer.2005.04.009

Cited by 25 publications

(16 citation statements)

References 35 publications

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“…After 20 min of mixing, the particle size of MPP‐2K‐WPU reactive dispersions increases to about 500 nm and the aggregating phenomena of particles are observed. The results validate that the particles aggregating process is related to the increase in particle size of MPP‐2K‐WPU system . As mixing progresses, the aggregating phenomena of particles are more evident, which are observed in the TEM image of MPP‐2K‐WPU reactive dispersions after 60 min of mixing.…”

Section: Resultssupporting

confidence: 75%

Maleopimaric acid‐modified two‐component waterborne polyurethane for coating applications

Si¹,

Liu²,

Shang³

et al. 2015

J of Applied Polymer Sci

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Maleopimaric acid (MPA), an important rosin derivative, was used to partially substitute isophthalic acid for the preparation of an anionic polyol (MPP) dispersion. The MPP dispersion was then applied to prepare a novel maleopimaric acid-modified two-component waterborne polyurethane (MPP-2K-WPU). The influences of NCO:OH molar ratio on the thermal properties, water absorption, surface free energy, and application properties of MPP-2K-WPU films were investigated. With increasing NCO:OH molar ratio, the thermal stability, pencil hardness, and ethanol resistance of MPP-2K-WPU films were improved, but the water resistance was enhanced firstly and then weakened. The surface free energy of MPP-2K-WPU films mainly depended on the dispersion interaction which was related to the structure of macromolecules. In addition, compared with the control sample of PP-2K-WPU(1.5:1) film, the MPP-2K-WPU(1.5:1) film exhibited improved thermal stability, water resistance, gloss, pencil hardness, and ethanol resistance.

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Section: Resultssupporting

confidence: 75%

Maleopimaric acid‐modified two‐component waterborne polyurethane for coating applications

Si¹,

Liu²,

Shang³

et al. 2015

J of Applied Polymer Sci

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“…When the scratch is exposed to UV for 10 min, the bands at 1566, 1535, and 1520 cm À1 corresponding to -NH 2 + CO 2 À increase significantly. 11,12 Also, the band at 1650 cm À1 characteristic of -NH 2 + -vibrations due to protonation of PUA increases. 13 These observations indicate that, under acidic conditions, PUA linkages of the OXE-CHI-PUR network are converted to carbamic acid, resulting in the expansion of the scratch due to the loss of CO 2 .…”

Section: Self-healing Under Protic Conditionsmentioning

confidence: 98%

Self-healing inside a scratch of oxetane-substituted chitosan-polyurethane (OXE-CHI-PUR) networks

2011

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“…1,5,14 Therefore, it is worth examining the evaporation fraction of the aqueous component involved in the reaction. 1,5,14 Therefore, it is worth examining the evaporation fraction of the aqueous component involved in the reaction.…”

Section: ͑6͒mentioning

confidence: 99%

Monte Carlo simulation of a film growth with reactive hydrophobic, polar, and aqueous components by a covalent bond fluctuating model

Yang

Pandey

2007

The Journal of Chemical Physics

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Using a bond fluctuating model (BFM), Monte Carlo simulations are performed to study the film growth in a mixture of reactive hydrophobic (H) and hydrophilic (P) groups in a simultaneous reactive and evaporating aqueous (A) solution on a simple three dimensional lattice. In addition to the excluded volume, short range phenomenological interactions among each constituents and kinetic functionalities are used to capture their major characteristics. The simulation involves thermodynamic equilibration via stochastic movement of each constituent by Metropolis algorithm as well as cross-linking reaction among constituents with evaporating aqueous component. The film thickness (h) and its interface width (W) are examined with a reactive aqueous solvent for a range of temperatures (T). Results are compared with a previous study [Yang et al. Macromol. Theory Simul. 15, 263 (2006)] with an effective bond fluctuation model (EBFM). Simulation data show a much slower power-law growth for h and W with BFM than that with EBFM. With BFM, growth of the film thickness can be described by h proportionaltgamma, with a typical value gamma1 approximately 0.97 in initial time regime followed by gamma2 approximately 0.77 at T=5, for example. Growth of the interface width can also be described by a power law, W proportionaltbeta, with beta1 approximately 0.40 initially and beta2 approximately 0.25 in later stage. Corresponding values of the exponents with EBFM are much higher, i.e., gamma1 approximately 1.84, gamma2 approximately 1.34 and beta1 approximately 1.05, beta2 approximately 0.60 at T=5. Correct restrictions on the bond length with the excluded volume used with BFM are found to have a greater effect on steady-state film thickness (hs) and the interface width (Ws) at low temperatures than that at high temperatures. The relaxation patterns of the interface width with BFM seem to change noticeably from those with EBFM. A better relaxed film with a smoother surface is thus achieved by the improved cross-linking covalent bond fluctuation model which is more realistic in capturing appropriate details of systems such as polyurethane film. The steady-state film thickness increases monotonically with the temperature possibly with two logarithmic dependences. The equilibrium interface width shows a nonmonotonic dependence: on increasing the temperature, Ws seems to increase slowly before it begins to decay Ws=4.12-1.39 ln(T).

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Dynamic colloidal processes in waterborne two-component polyurethanes and their effects on solution and film morphology

Cited by 25 publications

References 35 publications

Maleopimaric acid‐modified two‐component waterborne polyurethane for coating applications

Maleopimaric acid‐modified two‐component waterborne polyurethane for coating applications

Self-healing inside a scratch of oxetane-substituted chitosan-polyurethane (OXE-CHI-PUR) networks

Monte Carlo simulation of a film growth with reactive hydrophobic, polar, and aqueous components by a covalent bond fluctuating model

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