The synthesis and characterization of water-reducible nanoscale colloidal unimolecular polymer (CUP) particles

The coatings industry has adapted to more stringent guidelines in paint formulations. Current VOC (volatile organic compound) limits placed by the federal government have pushed the industry toward the development of paint formulations which have very little to no VOC\u27s. The development of Colloidal Unimolecular Polymer (CUP) particles is a step in the direction of providing a resin system which exists in zero VOC aqueous dispersion. The CUP particles are a part of the polymer field of Single Chain Nano Particles (SCNP) and ranged in diameters of 3-9 nm. The research presented in this dissertation describes the synthesis and design of these particles along with the various means of instrumentation used to gain insight into the structure and nature of these particles when suspended in aqueous medium --Abstract, page iv

Electroviscous Contribution to the Rheology of Colloidal Unimolecular Polymer (CUP) Particles in Water

The rheological characteristics of anionic colloidal unimolecular polymer (CUP) particles in water were investigated. the intrinsic viscosities were determined for CUPs with different molecular weights as a function of volume fraction. the specific viscosities were measured and fit with models considering hydrodynamic interaction and electroviscous effects. the rheological characteristics were consistent with a surface layer of water which increases with the particle size or molecular weight of CUPs. the effective charges on the surface of particle were calculated and correlated with the rheological behavior of the CUP particles from the dilute to semidilute range, a volume fraction of 0.0001-0.08

Self-assembly of Water Insoluble Polymers into Colloidal Unimolecular Polymer (CUP) Particles of 3-9 Nm

Colloidal Unimolecular Polymer, CUP, particles were synthesized and characterized as a potential new and useful spheroidal polymer conformation for a variety of applications. Also known as single chain nanoparticles, these nanomaterials are gaining in popularity. the route to CUP particle formation is an innovative approach utilizing a small number of hydrophilic groups along a hydrophobic polymer backbone which transitions from a random coil conformation in organic solvent to a hard sphere in water through a slow gradient with subsequent solvent removal. the CUP particles have diameters which are proportional to their molecular weights and range typically from 3 nm to over 9 nm. These CUP particles were stable in water and free of solvent or surfactants. the sodium or potassium salts of CUP particles are spheroidal and are able to be dried then re-dissolved in water with no aggregation, unlike the original polymer. the diameters of the CUP particles correlate with the absolute number average molecular weight (Mn) and distributions from the GPC. Molecular weights from 28K to 122K are reported here and are based on an acrylic copolymer having a molar ratio of 9:1 MMA:MAA

Molecular Weight (Mₙ) and Functionality Effects on CUP Formation and Stability

The formation of colloidal unimolecular polymer (CUP) particles from single polymer strands was investigated as a function of molecular weight. the CUP particle size was correlated with the absolute molecular weight and its distribution. the characteristics of the particles were evaluated with respect to viscosity, acid number, size distribution, and stability. the particle size varied from less than 3 nm to above 8 nm representing polymers with molecular weight in the range of 3000-153,000. Lower molecular weight polymers were found to be unstable. Particle size measurements using dynamic light scattering technique indicated a normal distribution which corresponded to the molecular weight distribution of the copolymer. the statistical distribution of the acid groups in the polymer chains played a significant role in the stability of low molecular weight polymers