Arm-First Convergent Iterative Methodology

The results of the 2G and 3G dendrimer-like star-branched polymers and block copolymers, after fractional precipitation, are summarized in Table 5.2. The resulting polymer all possessed the observed Mn values in good agreement with those calculated, and narrow molecular-weight distributions (M /Mn 1.1). Since the off-center living polymers and the 2G living dendrons used as subunits are sampled during the synthesis and well characterized prior to the synthesis and then reacted with a multifunctional core to synthesize the 2G and 3G polymers, this procedure corresponds to an example of an arm-first process. 

In the final reaction step, the propyl chloride reaction site of the IG or 2G dendron was linked with a multifunctional core, l,l,l-tris(4-hydroxyphenyl)ethane, by the same Williamson reaction, resulting in 2G and 3G dendrimer-like star-branched (PS)s. The resulting polymers had branched structure, three branches at the cores and two branches at the junctions in each generation layer. After fractionation, both purified polymers showed that the molecular weights are in excellent agreement with predicted values, and narrow molecular-weight distributions were attained MJM 1.05), as listed in Table 5.2. 

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