Preparation of Hyperbranched Polystyrene Homopolymers

The fractionation of each resultant broadly distributed hyperbranched polystyrene sample by precipitation led to a set of perfect narrowly distributed hyperbranched polystyrene chains with uniform subchains but different overall molar masses. We have, for the first time, experimentally elucidated their formation kinetics and established scaUng laws between their size and overall mass. Armed with such prepared hyperbranched chains, we will be able to further study correlations between their microscopic structures and macroscopic properties. In this section, we wiU focus on the formation kinetics section, and the fractal properties of these perfect hyperbranched polystyrenes will be discussed in the next chapter. 

Studies on Perfect Hyperbranched Chains Free in Solution and Confined in a Cylindrical Pore, Springer Theses, DOI 10.1007/978-3-319-06097-2 4, 

To obtain large hyperbranched polystyrene chains, the alkyne-azide click cycloaddition was used in our study because of its high efficiency and low susceptibility to side reactions without oxygen [7-9]. DMF was used as solvent in the self-poly-condensation of alkyne-(PSt-azide)2 after the removal of oxygen at 35 °C with a catalyst of CuBr-PMDETA. We first investigated how the initial molar mass and concentration of aIkyne-(PSt-azide)2 affect the kinetics of the selfpolycondensation of linear Seesaw-type polystyrene macromonomers. 

Note that it is better to describe the self-polycondensation in terms of the average degree of polycondensation (DP) [10-13], instead of the number and weight 

let us analyze the reaction kinetics of the interchain coupling of different macromonomers. On the basis of Fig. 4.4 and considering the nature of the selfpolycondensation, we can assume that it follows the 2nd-order kinetics, i.e., 

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Similar to the synthetic process of macromonomer polystyrene homopolymer, we have also synthesized Seesaw-type macromonomer triblock copolymer [1]. This is because we have been interested in the phase behaviors of long linear multiblock copolymer chains in selective solvents for many years [18, 19]. Therefore, we intentionally prepared Seesaw-type macromonomer triblock copolymers to construct hyperbranched block copolymers and study their solution properties. 

Preparation of Degradable Hyperbranched Polystyrene Homopolymers with Cleavable Disulfide Linkages... 

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