Synthesis of well-defined single and multiphase polymers using various living polymerization methods

Hexenyl functionalized poly(dimethylsiloxane) and methacryloyloxy functionalized poly(methyl methacrylate) (PMMA) and poly(dimethylsiloxane) (PDMS) macromonomers were synthesized using living polymerization techniques. The PDMS macromonomers were prepared by the anionic ring-opening polymerization of hexamethylcyclotrisiloxane followed by termination with a functionalized chlorosilane derivative. The methacryloyloxy functionalized PMMA macromonomers were prepared using group transfer polymerization with a protected hydroxyl functional initiator. The molar masses of the macromonomers ranged from 1000 g/mol up to 20000 g/mol with narrow molar mass distributions, less than 1.1, and high percent functionalities. The hexenyl functionalized PDMS macromonomers, having a range of molar masses, were statistically terpolymerized with l-butene and sulfur dioxide to yield poly(l-butene sulfone)-g-PDMS copolymers of various chemical compositions up to 20 wt% PDMS. The bulk and surface phase morphologies were investigated using DSC, TEM, XPS, and water contact angle measurements. The graft copolymer was shown to be an excellent resist for electron beam lithography with a 44u4C/cm4 sensitivity and a 33:1 etch ratio relative to a cross linked novolac resin. The 7000 g/mol methacryloyloxy functionalized PMMA macromonomers were copolymerized anionically with MMA to yield PMMA-g-PMMA polymers having absolute molar mass distributions less than 1.1 containing from 5 wt% to 40 wt% of the macromonomer at constant overall molar mass of 250000 g/mol. The graft polymers were utilized as model homopolymers exhibiting long chain branching. The methacryloyloxy functionalized PDMS macromonomers were free radically and anionically copolymerized with MMA to yield PMMA-g-PDMS copolymers. The graft copolymers were fractionated and their chemical composition distributions were determined as a function of copolymerization mechanism.

In addition, preliminary studies were started using aluminum-27 NMR to study several different aluminum porphyrins based on (5,10,15,20-tetraphenyl) porphine (TPPH₂) . The aluminum porphyrins were formed by reacting trimethylaluminum with TPPH₂ to yield TPPAIMe. The resulting aluminum porphyrin was modified by adding a stoichiometric amount of various carboxylic acids to form aluminum porphyrin carboxylates that had varying steric and electronic effects on the macrocycle.