A5045151950- Polymer composites and self-healing
- Advanced Polymer Synthesis and Characterization
- Building materials and conservation
- Surfactants and Colloidal Systems
- Material Properties and Processing
- Various Chemistry Research Topics
- Surface Modification and Superhydrophobicity
- Covalent Organic Framework Applications
- Asphalt Pavement Performance Evaluation
- Infrastructure Maintenance and Monitoring
- Conducting polymers and applications
- Architecture and Computational Design
University of Toronto
2019-2024
Waterborne two-component polyurethanes (WB 2K-PUs) represent an environmentally friendly alternative to solvent-borne coatings, with reduced use of volatile organic compounds (VOCs). These coatings still cannot achieve the outstanding performance 2K-PU formulations. In many WB formulations, a key step involves coalescence between polyol latex particles and nanoparticles formed from water-dispersible polyisocyanate (PIC). Interactions PIC take place both in aqueous medium after application...
We report experiments based upon fluorescence resonance energy transfer (FRET) measurements designed to examine mixing at the molecular level of components a waterborne 2K polyurethane (WB2KPU) formulation. The system consists an acrylic polyol latex (Mn = 4200 g/mol, D̵ 2, Tg ≈ 15 °C) with uniform hydrodynamic diameter (dh) 120 nm plus water-dispersible polyisocyanate (hmPIC, Basonat HW1000 from BASF). prepared labeled phenanthrene (Phen) as donor dye or dimethylaminobenzophenone (Nben)...
In a previous publication [Macromolecules 2019, 52, 5245–5254], we described the synthesis of surfactant-free latex dispersions nanoparticles (NPs) based on emulsification preformed proprietary BASF polymer (MnGPC = 5000 g/mol, D̵ 3), in which −COOH groups were partially neutralized by using ammonia. The NPs these then cross-linked with neopentyl glycol diglycidyl ether (NGDE) to increase molecular weight, followed reaction monoglycidyl reduce acid number and lower glass transition...
Abstract We examine the nature of chemical reactions taking place in a waterborne two‐component polyurethane formulation consisting an acrylic polyol latex and hydrophilically modified polyisocyanate (hmPIC) based on trimer hexamethylene diisocyanate. The hmPIC was diluted with 30 wt.% organic solvent to reduce its viscosity formed small (~20 nm) droplets when dispersed water. In mixtures hmPIC, we monitored rate NCO group disappearance state by FTIR showed that it varied choice solvent....
While the interaction of NCO with carboxylic acids has been documented, a comprehensive knowledge its effect on film formation in two-component waterborne polyurethane (2K-WPU) system is lacking. In this work, we synthesized series carboxyl-functional acrylic polyols (Mn ≈ 5000 g/mol, Đ 2.7, Tg 15 °C) uniform diameter (120 nm) varying amounts methacrylic acid introduced into latex. For 2K-WPU dispersions molar NCO/OH ratio 1.3:1, monitored particle size by dynamic light scattering and...
Research Article| November 01 2018 Why Dehydration Was Invented Margaret Zhang used to go by Mar-gar-gar. She likes waste gas, write poetry, and wander the streets of Chinatown. Read her work in Salt Hill Journal, Softblow, Dialogist, Gigantic Sequins, other journals. is editor-in-chief Glass Kite Anthology an undergraduate at University Pennsylvania. Search for works this author on: This Site Google minnesota review (2018) (91): 26–27. https://doi.org/10.1215/00265667-7137123 Cite Icon...