pH-Responsive polymers

Electrochemical reduction of an exemplary ATRP catalyst, C 11 Br 2 /Me 6 TREN, is shown to be an efficient process to mediate and execute an ATRP. The onset of polymerization occurs only through passage of a cathodic current achieved under a reductive potential to form Cu 1 Br 2 /Me 6 TREN, within the reaction medium. Unprecedented control over the polymerization kinetics can be attained through electrochemical methods by modulating the magnitude of the applied potential allowing polymerization rate enhancement or retardation. Additional polymerization control is gained through electrochemical “dials” allowing polymerization rate enhancements achieved by larger applied potentials and the ability to successfully switch a polymerization “on” and “off between dormant and active states by application of multistep intermittent potentials.

https://science.sciencemag.org/content/sci/332/6025/81.full.pdf

Electrochemically mediated atom transfer radical polymerization

Review of ASP EOR (alkaline surfactant polymer enhanced oil recovery) technology in the petroleum industry: Prospects and challenges

Pyrolysis kinetics and thermal behavior of waste sawdust biomass using thermogravimetric analysis

Biodegradable polymers have met with an increasing demand in medical usage over the last decades. One of such polymers is poly(e-caprolactone) (PCL), which is a polyester that has been widely used in tissue engineering field for its availability, relatively inexpensive price and suitability for modification. Its chemical and biological properties, physicochemical state, degradability and mechanical strength can be adjusted, and therefore, it can be used under harsh mechanical, physical and chemical conditions without significant loss of its properties. Degradation time of PCL is quite long, thus it is used mainly in the replacement of hard tissues in the body where healing also takes an extended period of time. It is also used at load-bearing tissues of the body by enhancing its stiffness. However, due to its tailorability, use of PCL is not restricted to one type of tissue and it can be extended to engineering of soft tissues by decreasing its molecular weight and degradation time. This review ou...

PCL and PCL-based materials in biomedical applications

Polymers for enhanced oil recovery: A paradigm for structure–property relationship in aqueous solution

Low salinity polymer flooding: Lower polymer retention and improved injectivity

https://pure.rug.nl/ws/files/6738589/2009_FoodBioprodProcess.Manurung.pdf

Valorisation of Jatropha curcas L. plant parts : Nut shell conversion to fast pyrolysis oil

A series of block copolymers of acrylamide and N-isopropylacrylamide (NIPAM) characterized by different ratios between the length of the two blocks have been prepared through atomic transfer radical polymerization in water at room temperature. The solution properties of the block copolymers were correlated to their chemical structure. The effect of the hydrophilic/hydrophobic balance on the critical micelle concentration (CMC) was investigated. The CMC increases at higher values for the solubility parameter, thus indicating a clear relationship between these two variables. In addition, the solution rheology (in water) of the block copolymers was studied to identify the effect of the chemical structure on the thermo-responsiveness of the solutions. An increase in the length of the PNIPAM block leads to a more pronounced increase in the solution viscosity. This is discussed in the general frame of hydrophobic interactions strength. The prepared polymers are in principle suitable for applications in many fields, particularly in enhanced oil recovery. (C) 2013 Wiley Periodicals, Inc.

Acrylamide-b-N-isopropylacrylamide block copolymers : Synthesis by atomic transfer radical polymerization in water and the effect of the hydrophilic-hydrophobic ratio on the solution properties

Atomic transfer radical polymerization (ATRP) of acrylamide has been accomplished in aqueous media at room temperature. By using methyl 2-chloropropionate (MeClPr) as the initiator and tris[2-(dimethylamino)ethyl]amine (Me6TREN)/copper halogenide (CuX) as the catalyst system, different linear polyacrylamides with apparent molecular weights up to >150 000 g/mol were synthesized with dispersities as low as 1.39. The molecular weights agreed well with the theoretical ones at relatively low-medium monomer/initiator ratios (<700:1). Initial chain extension experiments (isolated macroinitiator) resulted in a polymer with bimodal distribution. However, in situ chain extension experiments, carried out by addition of a second fresh batch of monomer to the reaction mixture, confirmed the living nature of the polymerization. By adding a fresh batch of monomer to a linear macroinitiator (Mn = 22 780 g/mol, PDI = 1.42) in solution, an increase in the molecular weight up to 30 220 g/mol (PDI = 1.64) was observed. In ad...

/pdf/acrylamide-homopolymers-and-acrylamide-n-isopropylacrylamide-5sph1vd3zd.pdf

D. A. Z. Wever

Papers

Polymers for enhanced oil recovery: A paradigm for structure–property relationship in aqueous solution

Low salinity polymer flooding: Lower polymer retention and improved injectivity

Valorisation of Jatropha curcas L. plant parts : Nut shell conversion to fast pyrolysis oil

Acrylamide-b-N-isopropylacrylamide block copolymers : Synthesis by atomic transfer radical polymerization in water and the effect of the hydrophilic-hydrophobic ratio on the solution properties

Acrylamide Homopolymers and Acrylamide–N-Isopropylacrylamide Block Copolymers by Atomic Transfer Radical Polymerization in Water