Experimental And Simulation Studies Of Cumulative Structural Factors And Instantaneous Values Of Gradient Copolymers

In this thesis the cumulative structural factors and instantaneous values of gradient copolymers and the relationship between them was studied.The copolymer of p-fluorostyrene(p-FSt)and methyl acrylate(MA)were prepared using atom transfer radical polymerization(ATRP)catalyzed by CuBr /N,N,N,N,N-pentamethyldiethylenetriamine(PMDETA)in bulk at 105℃.Plots of ln([M]₀/[M])vs time and(?)_n vs monomer conversion were linear.The copolymer polydispersities were low.The result show the copolymerzation is "living".The cumulative compositions were determined by using the aromatic and methoxy proton resonance from ¹H NMR spectra.The triad sequences were determined by using the C1 ipso region(aromatic C1 carbon)and the carbonyl resonance frequencies from the spectra.The triad concentrations were obtained by ¹³C NMR spectra.The monomers feed ratios were obtained by ¹H NMR spectra.Instant reaction probabilities were calculated by the theory of conventional copolymerizations,so instantaneous composition percent and instantaneous triad concentrations were obtained.Computer simulation is apply into Living Radical Polymerization(LRP),the computer will produce Markov chains which contain activation-deactivation process.The computer model can be described as a tetrapolymerization which is based on the propagation reactions,the reaction probabilities will change with the conversion.Getting rid of the nominal structure related to dormancy in the chain,then cumulative values of composition,segment length distribution and triad concentrations are achieved.Instant reaction probabilities can obtained by instant monomers feed ratio,then instantaneous values of composition,segment length distribution and triad concentrations are achieved.The instantaneous structural factors of gradient copolymer characterized the dynamic micro-structure well.The accumulated values calculated by formula agree well with the cumulative structural factors.The result indicate that the theory of conventional copolymerizations also apply to ATRP.Also proved the dormant/activate reaction has no effect on living/controlled copolymer's micro-composition and micro-sequence structure...