Radical copolymerizations of 2-hydroxyethyl methacrylate (HEMA) with n-butyl methacrylate (BMA) and n-butyl acrylate (BA) were carried out in xylene, DMF, and n-butanol solutions. Solvent effects on copolymerization propagation kinetics were investigated using pulsed laser polymerization (PLP) combined with size exclusion chromatography (SEC) as well as proton NMR, while starved-feed higher temperature semibatch reactions were carried out in different solutions to simulate industrial production. Solvent choice, through its influence on hydrogen bonding of HEMA monomer, has a significant impact on the copolymer composition and propagation rate coefficient and thus influences the semibatch polymerization behavior of BMA/HEMA, as previously found for the styrene/HEMA system. The presence of HEMA leads to increased polymer molecular weight, a result attributed to branching reactions involving dimethacrylate impurity. Although H-bonding (and solvent choice) influences BA/HEMA kinetics, its relative effect is negligible on semibatch operation under the conditions studied.

In this work PEGylated polyester-based nanoparticles (NPs) for drug delivery applications were synthetized through emulsion free radical polymerization. These NPs are produced starting from functionalized macromonomers whose average chain length can be tuned in a controlled way. Since the degradation of these NPs occurs through the hydrolysis of side chains, by tuning their length it is possible to obtain NPs with a controllable degradation time, comparable to data obtained with NPs internalized into cells. The long-term colloidal stability of these NPs in isotonic environment has been assessed through dynamic light scattering measurements and their degradation rate in cell medium has been proved to be fast and controllable. The NP behavior in gastric and intestinal solution was also studied.

We synthesized hydrolytically degradable cationic polymers by micellar radical polymerization of a short-chain polyester macromonomer, polycaprolactone choline iodide ester methacrylate (PCLChMA) with two polyester units, and used them to flocculate oil sands mature fine tailings (MFT). We evaluated the flocculation performance of the homopolymer and copolymers with 30 mol % acrylamide (AM) by measuring initial settling rate (ISR), supernatant turbidity, and capillary suction time (CST) of the sediments. Flocculants made with trimethylaminoethyl methacrylate chloride (TMAEMC), the monomer corresponding to PCLChMA with n = 0, have improved performance over poly(PCLChMA) at equivalent loadings due to their higher charge density per gram of polymer. However, MFT sediments flocculated using the PCLChMA-based polymers are easier to dewater (up to an 85% reduction in CST) after accelerated hydrolytic degradation of the polyester side chains. This study demonstrates the potential of designing cationic polymers that effectively flocculate oil sands tailings ponds, and also further dewater the resulting solids through polymer degradation.

Micellar radical polymerization of a short‐chain polyester macromonomer, polycaprolactone choline iodide ester methacrylate (PCLnChMA), is used to produce a new cationic flocculant that becomes more hydrophobic in response to hydrolytic degradation. The cationic tips of the comb‐like poly(PCL3ChMA) accelerate the settling rate of oil sands tailings, while partial hydrolysis of the polyester grafts reveals the hydrophobic segments that reduce capillary suction time by 30%. This technology combines the material properties of polyesters with the productivity of radical polymerization to make dual functional flocculants with characteristics that can be easily tuned to control flocculation performance, such as polymeric cation density, hydrophobic content, and polymer architecture.