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The Effects of Urethane Methacrylates on the Film Properties of Acrylic-Urethane Hybrid Latexes

Cobaj, Anisa
http://rave.ohiolink.edu/etdc/view?acc_num=akron1560335362557041

Abstract Details

2019, Doctor of Philosophy, University of Akron, Polymer Engineering.
Latexes are stable aqueous dispersions of polymeric particles prepared via emulsion polymerization process. The requirements of high performing latex are to have good mechanical properties and a smooth film formation. To achieve the required balance, polymer composition and polymer morphology of latexes has been modified. A urethane methacrylate monomer, (MEM) was synthesized via a non-isocyanate pathway and incorporated into acrylic-urethane hybrid latexes via seeded semi-continuous monomer starved polymerization. Acrylic-urethane hybrid latexes were prepared by copolymerization of MEM with MMA and BA in homogeneous and core-shell latexes. Particle size and morphology was evaluated by DLS, TEM and AFM. The behavior of urethane monomer in acrylic latexes and the effect of urethane functionalized latexes on film formation, viscoelastic and mechanical properties was studied via MFFT, DMTA, tensile and coatings testing. Hydrogen bonding of urethanes with water had a plasticizing effect during film formation. As a result, Tg-MFFT of acrylic-urethane latexes was higher than that of acrylic latexes. In comparison to the control acrylic latex, acrylic-urethane hybrids showed improvement in viscoelastic properties and in mechanical properties as function of MEM concentration in latexes. Moreover, core-shell latexes outperformed homogeneous latexes. Hydrogen bonding of MEM functionalized homogeneous and core-shell latexes was quantified via ATR-FTIR. With more MEM in the homogeneous and core-shell latexes, hydrogen bonding strength was enhanced, which was displayed by the frequency shift of both N-H and C=O stretching bands and by increase in the area of the hydrogen bonded N-H and C=O stretching bands. Fraction of hydrogen bonded C=O groups was calculated and compared for the homogeneous and core-shell latexes as a function of increasing MEM concentration in latex. A simplistic method to synthesize urethane methacrylate monomers without purification was used to prepare MEM and methacrylic acid. MEM and MAA functionalized homogeneous latex systems were prepared via seeded semi-continuous monomer starved conditions. Particle size, particle size distribution and morphology of latexes was evaluated via DLS and AFM. Film formation, viscoelastic and mechanical properties of acrylic-urethane hybrid latexes were examined and the film properties were dependent on the concentration of MEM and MAA monomers in latex. A composition drift was observed for high MEM+MAA concentration in latex In the last chapter, a di-urethane methacrylate monomer (HHM) was synthesized via the isocyanate pathway and copolymerized with MMA and BA in a homogeneous latex. Film formation, viscoelastic and mechanical properties were improved with higher functionality of HHM in the system. Particle size of latex was increased with higher HHM concentration in latex. When keeping Tg the same, lower MFFT was observed as the amount of HHM in latex increased.
Mark Soucek (Advisor)
Kevin Cavicchi (Committee Chair)
Nicole Zacharia (Committee Member)
Tianbo Liu (Committee Member)
Michael Cheung (Committee Member)
244 p.
Polymer Chemistry; Polymers

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Citations

  • Cobaj, A. (2019). The Effects of Urethane Methacrylates on the Film Properties of Acrylic-Urethane Hybrid Latexes [Doctoral dissertation, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1560335362557041

    APA Style (7th edition)

  • Cobaj, Anisa. The Effects of Urethane Methacrylates on the Film Properties of Acrylic-Urethane Hybrid Latexes. 2019. University of Akron, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=akron1560335362557041.

    MLA Style (8th edition)

  • Cobaj, Anisa. "The Effects of Urethane Methacrylates on the Film Properties of Acrylic-Urethane Hybrid Latexes." Doctoral dissertation, University of Akron, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1560335362557041

    Chicago Manual of Style (17th edition)

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This open access ETD is published by University of Akron and OhioLINK.