Computer Simulation For The Effect Of The Dormant/activate Reaction On The Sequence Structure Of Atom Transfer Radical Copolymer

In this thesis the sequence distribution of the Intermittent Atom Transfer Radical copolymerization products was studied in system.A new method is proposed to handle the ATRcP as well as structures of the products. The computer model can be described as a tetrapolymerization which is based on the propagation reactions. Once the every propagation and intermittant reaction probabilities were given, the computer will produce Markov chains which contain activation-deactivation process under the stationary condition. When getting rid of the nominal structure related to dormancy in the chain, the remained chain corresponds to an average molecular chain.Another dynamic computer simulation program is developed to get the more convincing results. Chains of which the lengthes obey the Poisson distribution are produced by this effective model according to the changing probabilities, which are calculated by the instant concentration of monomers. Through recording the number of reacted monomers and calculating the number of left ones, instant probabilities are got when the reactivity ratios and the initiator selectivities to monomers are considered. Statistic is carried on under certain conversions, so segment length distribution, average composition in polymers and various of triads are available and relations between the given parameters(reactivity ratios, initiator selectivity to monomers and initial feed composition, etc.) and the concentration of triads are achieved..The carbon-13 NMR spectras of p-FSt/MA copolymers with feed composition f_s equals to 0.33 was investigated. The trends of the cumulative triads concentration are compared with those of the dynamic simulation results.The results show that under stationary and dynamic condition, ATRcP products have the same composation ratio and sequence structure comparing to that of FRcP, and the results got from expriment also proved the correctness of the computer simlation. The results indicate that the existence of the dormancy affects neither the instant composition nor the instant sequence distributions of ATRcP products. Both are identical with that of conventional copolymerizations.