Step polymerization functional group accessibility

Benzylic boronic esters [52]can be obtained from bromomethyl boronic esters and aryl or vinyl stannanes [53]. Alkyl and vinyl boronic esters are accessible through hydroboration of alkynes with dialkylboranes followed by oxidation with acetaldehyde [43]. Alternatively, vinylboronates can be obtained directly from alkynes in a reaction -with catecholborane without a subsequent oxidation step [53]. Further diversification in the boronic acid derivatization is achieved by binding the boronic acids bearing another derivatizable functional group (for instance an amine) to suitable polymeric supports. The modified boronic acid may then be... 

To fully exploit the beneficial properties of PIB in, for example, polyurethanes, thermoplastic elastomers, and sealants, controlled polymerization methods are required that provide access to controlled end-group functionalities. The controlled polymerization of isobutene was first reported by Kennedy, which was based on the inifer technique. This so-called inifer that is added to provide control over the polymerization is a compound that acts both as the initiator and the transfer agent. The inifer deliberately induces chain transfer to control the molecular weight of the PIB, whereby each transfer step generates... 

Karesoja and coworkers reported grafting of clay with butyl acrylate and MMA by ATRP [60]. An ATRP initiator with trichlorosilane functionality was synthesized reacted with the hydroxyl groups on clay surfaces and initiated the copolymerization of BA and MMA. The three-step reaction was schemed in Figure 10.12. The ll-(2-bromo-2-methyl)propionyl-oxy-undecyl trichlorosilane ATRP initiator was covalently attached to clay platelets via silylation reactions. The initiator clay was used to polymerize BuA and MMA in the bulk monomer solution or dimethyl sulfoxide (DMSO). They found in the nanocomposites prepared from DMSO clay was well dispersed as individual platelets however, in the nanocomposites prepared from bulk solution big aggregates of clay platelets were observed. This indicates that DMSO is able to expand the distance between the clay layers and make the clay gallery more accessible to chemicals. 

---