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Ceresa, Raymond John (1960) The reactions of polymeric free radicals produced by mechanical degradation during cold mastication. Doctoral thesis, Northern Polytechnic.
A range of plastomers has been plasticised by both heat and solvents to achieve the rubbery state and degraded by mechanical scission to produce polymeric free radicals. The termination process in the presence absence of free radical acceptors has been studied and the effect of temperature, plasticity, rate of shear and molecular weight on the rate and extent of breakdown, investigated.
The polymeric free radicals so produced have been utilised to synthesise block copolymers by masticating a range of polymers plasticised with polymerisable vinyl monomers. Fractional and selective precipitation techniques were devised to separate the block copolymers from the homopolymers also present. Characterisation of selected block copolymers confirmed the essential linearity of their structure.
Linear Block Copolymers of polymethyl methacrylate and polyacrylonitrile were synthesised by the cold mastication process, isolated and characterised. The mastication parameters were adjusted to give a range of clock copolymers covering a wide specrum of compositions. The effect of composition on the solution properties was studied and the presence of two species of linear block copolymer established.
The system polyvinyl chloride/methyl methacrylate was shown to behave abnormally during mastication and theaccelerating effects of inorganic and organic additives was investigated.
The synthesis of linear block copolymers by the cold mastication of high polymer/monomer mixtures was shown to have extensive applications giving a unique range of interpolymeric products.
The presence of trapped polymeric radicals with very long lifetimes was illustrated in masticated polymeric mixtures which had been taken to high conversions through a highly viscous phase.
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