A coil-to-globule transition in macromolecules of methyl methacrylate (Co)polymer in solvent-precipitating agent mixtures

The nanosecond mobility of PMMA macromolecules and MMA copolymers with meth yl acrylate (5-20 mol %) and methacrylic acid (6 mol %) was studied in a to luene-octane mixture. The polarized luminescence excited by a pulsed synchr otron radiation facility in Daresbury, UK was used to determine the relaxat ion times on a nanosecond time scale. The measurements were performed at a low polymer content in solution (0.01%). The polymers with covalently bound anthracene-bearing luminescent labels (a label per 1000 monomeric units) w ere used. When the solvent contained 22 wt % octane, a compact globular str ucture was formed in the PMMA macromolecules. The effect of methacrylic uni ts on the formation of the globular structure in the MMA copolymer macromol ecules was revealed.