Novel polymeric surfactants to stabilise emulsions
File(s)
Author(s)
Somuncuoglu, Birsen
Type
Thesis
Abstract
This PhD project aims to synthesise polymeric surfactants, characterise their aqueous solution properties and emulsifying abilities, and obtain a structure-property relationship. In this study, different polymeric surfactants were synthesised using Group Transfer Polymerisation (GTP) method.
The first project of this PhD thesis includes the synthesis of two series of diblock copolymers and the characterisation of their aqueous solution properties and emulsifying abilities. In order to make a comparison between the two-polymer series, the molar mass (MM), composition and hydrophobic monomer kept the same, whereas different hydrophilic monomer used for each polymer series. Thus, in both series, ethyl methacrylate (EtMA) was used as a hydrophobic monomer, and poly(ethylene glycol) methyl ether methacrylate (PEGMA) and 2-(dimethylamino) ethyl methacrylate (DMAEMA) was used as a hydrophilic monomer in Polymer series 1 and 2, respectively.
The second project of this PhD thesis includes the synthesis of triblock copolymers using the same monomers studied in the previous project; PEGMA, EtMA and DMAEMA. The architecture of the linear triblock copolymers is ABC (A is PEGMA, B is EtMA, and C is DMAEMA), and it kept the same in the whole project. Moreover, the MM and composition of the copolymers kept the same as with the previous chapter to observe the effects of diblock and triblock copolymers on their properties.
The third project of this PhD thesis includes the synthesis of seven different architecture of copolymers varying from statistical to gradient, diblock, triblock copolymers. The copolymers were based on hydrophilic DMAEMA and hydrophobic n-butyl methacrylate units. The MM and composition kept constant to observe the effect of architecture on the emulsifying and aqueous solution properties.
It was found that the all the polymers were successfully synthesised and the effective pKa (if any), cloud points, critical micelle concentrations (CMC) and hydrophile-lipophile balance (HLB) values, and hydrodynamic diameters were affected by the structure of the polymers, such as composition and MM. Most importantly, all polymeric surfactants were found to emulsify methyl laurate in water, and the stability of the emulsions was found to strongly depend on the architecture, composition and MM of the polymers.
The first project of this PhD thesis includes the synthesis of two series of diblock copolymers and the characterisation of their aqueous solution properties and emulsifying abilities. In order to make a comparison between the two-polymer series, the molar mass (MM), composition and hydrophobic monomer kept the same, whereas different hydrophilic monomer used for each polymer series. Thus, in both series, ethyl methacrylate (EtMA) was used as a hydrophobic monomer, and poly(ethylene glycol) methyl ether methacrylate (PEGMA) and 2-(dimethylamino) ethyl methacrylate (DMAEMA) was used as a hydrophilic monomer in Polymer series 1 and 2, respectively.
The second project of this PhD thesis includes the synthesis of triblock copolymers using the same monomers studied in the previous project; PEGMA, EtMA and DMAEMA. The architecture of the linear triblock copolymers is ABC (A is PEGMA, B is EtMA, and C is DMAEMA), and it kept the same in the whole project. Moreover, the MM and composition of the copolymers kept the same as with the previous chapter to observe the effects of diblock and triblock copolymers on their properties.
The third project of this PhD thesis includes the synthesis of seven different architecture of copolymers varying from statistical to gradient, diblock, triblock copolymers. The copolymers were based on hydrophilic DMAEMA and hydrophobic n-butyl methacrylate units. The MM and composition kept constant to observe the effect of architecture on the emulsifying and aqueous solution properties.
It was found that the all the polymers were successfully synthesised and the effective pKa (if any), cloud points, critical micelle concentrations (CMC) and hydrophile-lipophile balance (HLB) values, and hydrodynamic diameters were affected by the structure of the polymers, such as composition and MM. Most importantly, all polymeric surfactants were found to emulsify methyl laurate in water, and the stability of the emulsions was found to strongly depend on the architecture, composition and MM of the polymers.
Version
Open Access
Date Issued
2021-06
Date Awarded
2021-10
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Georgiou, Theonitsa
Sponsor
Imperial College London
Engineering and Physical Sciences Research Council (EPSRC)
Grant Number
MMAC F48087
Publisher Department
Materials
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)