Characterization from PMMA chain

The PMMA-Phe synthesis, characterization, film preparation, apparatus and experimental scheme are described elsewhere (H) Briefly, the PMMA chains, copolymerized from MMA and Phe-labelled monomers, were characterized via gel permeation chromatography (GPC) M = 411,000, M = 197,000 and M M - 2.08. UV-absoifption measurementsnindicated that ca. I % of all monomer units were Phe-labelled. The sample was dissolved in toluene and was spin-coated onto 1-inch diameter quartz disks. Then, the films (ca. 1 /zm thick) were annealed at 160 C for 60 minutes under vacuum. 

The average time determined experimentally from the slope of linear dependence Y Tln) is given by Eq. (5,5.3). The data on PMMA listed in Table 21 show how the structure of the side chain bonding the LG to the main PMMA chain and the position of the attachment of this side chain to LG (to the anthracene ring) affect the times characterizing the rate of rearrangements in side chains with LG. 

The polymers initiated by BP amines were found to contain about one amino end group per molecular chain. It is reasonable to consider that the combination of BP and such polymers will initiate further polymerization of vinyl monomers. We investigated the photopolymerization of MMA with BP-PMMA bearing an anilino end group as the initiation system and found an increase of the molecular weight from GPC and viscometrical measurement [91]. This system can also initiate the photopolymerization of AN to form a block copolymer, which was characterized by GPC, elemental analysis, and IR spectra. The mechanism proposed is as follows ... 

This can be seen from the data in Table 10.1, where isotactic, syndiotactic, and atactic poly(methyl methacrylate) (PMMA) have different a values. If the size of a polymer chain can be affected by its configuration, the microstructure must be well characterized before an accurate assessment of experimental data can be made. This can be achieved using nuclear magnetic resonance (NMR) and infrared techniques. 

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