Estimation of Bound Carbonyls in PMMA-r-PS Copolymers Adsorbed on Silica
This document has been relocated to http://scholarsmine.mst.edu/chem_facwork/2409
There were 8 downloads as of 28 Jun 2016.
The adsorption of random copolymers on solid surfaces is essential for developing good properties in composite materials. A good control and understanding of interfaces allows tuning of the properties of the individual components. Interfacial polymers are important in many industrial applications such as photoresists, protective coatings, metal insulator and semi-conductor insulator junctions, metal-filled polymer composites and polymer-lined metal containers for protective food packaging. The effect of the drying process,1 configuration and tacticity,2 molecular mass, density of surface hydroxyls,3 and adsorbed amounts4 have already been studied for interfacial polymers. The thermal characterization for polystyrene,5 PMMA11 and PMMA-r- PS6 copolymers adsorbed on silica have been studied recently by our research group. One of the important considerations for adsorbed copolymer composites was the composition of the copolymer and the individual surface affinities of monomer units on the substrate. The dependence of chain length, blockiness and self-association of the chain was also a consideration for these composites.7 Bound carbonyls are the ones which hydrogen bond directly with surface hydroxyls that, in our case, are the hydroxyls on silica. Transmission FTIR is one of the simplest techniques used to estimate the number of bound carbonyls. It was shown that the bound fractions decreased with increased adsorbed amounts while molecular weights8 indicated a flattened configuration for lower adsorbed amounts and shorter chains. However, the dependence of bound fractions on molecular mass9 was dramatically less.