The innovation engine for new materials

Annabelle Lee


University of California, Santa Barbara



Site Abroad: 

Technical University Eindhoven, Netherlands


Louis Pitet

Faculty Sponsor(s): 

E. W. Meijer

Project Title: 

Synthesis and Characterization of PDMS-b-PLA and Investigation of a Supramolecular Graft Copolymer

Project Description: 

The behavior of covalently bonded block copolymers was compared with supramolecular block copolymers with reversible, non-covalent interactions linking the respective components. The consequences of the different connectivity were investigated through covalently bonded poly(dimethylsiloxane)-block-poly(lactide) (PDMS-b-PLA) and supramolecular poly(styrene)-g-poly(lactide) (PS-g-PLA). Conventional methods were used to synthesize PDMS--PLA and were characterized using proton nuclear magnetic resonance (1H NMR), size exclusion chromatography (SEC), differential scanning calorimetry (DSC) and thin films were imaged with atomic force microscopy (AFM). The block copolymers exhibited nearly identical thermal properties to the respective homopolymers, which suggested that they adopt micro-phase separated morphologies. This behavior was corroborated with AFM performed on thin films spin coated on silicon wafers. A supramolecular graft copolymer consisting of a PS main chain and PLA grafts linked through quadruple hydrogen bonding motifs were investigated.5,6 Polystyrene functionalized with ureidopyrimidinone (UPy) and PLA with a terminal 2,7-diamido-1,8-naphthyridine (Napy) were mixed to yield PS-g-PLA. The formation of hydrogen bonds was verified with 1H NMR spectroscopy.