| Popis: |
Using anionic polymerisation techniques, a series of poly(methyl methacrylate) polymers bearing a variety of end-functions has been synthesised. The use of a delocalised and sterically hindered initiator, I,I-diphenylhexyllithium in conjunction with lithium chloride has allowed the production of polymers of well defined molecular weight and narrow molecular weight distributions (Mw/Mn=1.1). End-group functionality has been incorporated by the use of terminating agents bearing a functional group. Functionalities achieved by this method include nitrobenzoyl and nitrobenzyl. The degree of functionality has varied between 50 and 85 %. By the use of selective reduction, these end-groups have been converted to amine functions. Significant loss of functionality occurred during the reduction process and overall amine functionality varied between 20 and 50 %. The use of a functional initiator bearing a protected amme function, 1-(4- benzophenone iminophenyl)-I-phenylethylene has allowed the incorporation of an imine end-function. Mild acid-catalysed hydrolysis has then given quantitative amine endfunctionalisation of PMMA. Charaterisation of functionalised PMMA polymers has been by IH and I3C NMR spectroscopy, GPC and MALDI-TOF-MS. The combined use of NMR spectroscopy and MALDI-TOF-MS has allowed the full characterisation of all end-groups present on low molecular weight samples. Grafting reactions of the amine functionalised PMMA have then been investigated. Grafting onto epoxidised natural rubber, a styrene-maleic anhydride copolymer and epoxy surface-functionalised emulsion particles have been attempted. GPC and modulated temperature DSC have been used to characterise these products. |
