Poly (Lauryl Methacrylate): spread monolayers and bulk configuration

Abstract

Deuterated variations of poIy(lauryl methacrylate) (PLMA) have been synthesised, this involved the initial synthesis of the monomer (LMA). This was achieved by a transesterification reaction between methyl methacrylate and lauryl alcohol using either hydrogenous or deuterated materials depending on which part of the resulting LMA monomer was to be deuterated. The physical properties of PLMA and LMA spread monolayers have been investigated using surface pressure - area isotherms and surface quasi - elastic light scattering (SQELS). The isotherms for PLMA show that the thermodynamic state of the polymer is poorer than theta conditions and no variation occurs with changes in temperature. LMA shows a drastic change in the nature of the isotherm as the temperature is varied. This has been attributed to the formation of lenses and the variation caused by temperature is due to a change in the rate of migration of the LMA molecules. The SQELS results show that the PLMA monolayer displays the characteristics of a Voigt solid model and shows no viscous relaxation processes. SQELS has also been used to demonstrate the biphasic nature of the monolayer at low surface concentrations, the size of the polymer 'islands' has been estimated to be in the range of 5 to 20mm. SQELS from LMA monolayers showed that the two higher surface concentrations gradually converted into the same state as that obtained for the low