PMMA-6-PTBMA precursor

Fig. 17 A LCCC chromatograms of PtBMA-l7-PMMA. Precursor PMMA (Mj,=31.0 kg/mol) with different PtBMA block lengths (Mj =0,46.3,85.3 kg/ mol) at the critical condition of Pt-BMA. Column two Nucleosil C18 250x4 mm 300 A and 1,000 A. Eluent THF/CH3CN (49.5/50.5, w/w). B LCCC chromatograms of PMMA-block-PtBMA. Precursor PtBMA (Mj = 73.0 kg/mol) with different PMMA block lengths (Mj,=29.6, 108, 167 kg/mol) at the critical condition of PMMA. Column two Nucleosil 150x4 mm, 100 A and 250x4 mm, 300 A. Eluent THF/fj-hexane (82/18, w/w). Reproduced from [44] with permission...

The average molar masses of components of block copolymers PMMA-PtBMA estimated by LC under critical conditions (for polymer eluted in SEC mode) agree very well with values SEC obtained by subtracting the molar mass of the PtBMA precursor from that of the block (deviation 2-4 %) [55]. Agreement up of individual component ratio of 1 5 was found. On the other hand, Lee et al. [39,78] have found systematic difference 0-33% between by critical conditions measured the molar mass of precursor and expected molar mass of precursor. Differences between measured, and expected, molar masses increased with the concentration of the invisible part of copolymers (i.e. part of copolymer under critical conditions). Additional studies are needed to generalize this phenomenon. 

Figure 6. GPC behavior of PMMA-b-PTBMA diblock precursor and acid catalyzed hydrolysis product.

Similarly, stable macroanions obtained by the subsequent metalation of the proper end groups such as diphenylvinyl and diphenylmethoxy were used in the living polymerization of tBMA yielding PIB-l7-PtBMA block copolymers with almost quantitative efficiency (Scheme 35). Moreover, amphiphilic polymeric materials can be prepared by hydrolysis of ester moieties of the polymers obtained by this method for instance, amphiphilic PIB-I7-PMAA diblock was prepared by the hydrolysis of the acrylate segment of the suitable precursor copolymer. A series of linear and star copolymers consisting of PIB and PMMA were also prepared. ... 

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