Synthesis, Characterization And Self-Assembly Properties Of Fluorinated Polyolefin-Based Copolymers

Amphiphilic block copolymers have potential applications in nanoscience andnanotechnology (drug and gene carriers, diagnostic imaging and nano-reactors, etc.), whichcausing the extensive attention and research. Polyisobutylene is recognized for itsenvironmental stability, bio-security, excellent biocompatibility, as well as superiorgas-barrier in industry area in recent years. Amphiphilic block copolymers whichcontaining polyisobutylene are reported very rarely. Our groups have synthesizedamphiphilic block polymers based on polyisobutylene. However the reports aboutfluorinated polyisobutylene derivatives are rare. This paper mainly focuses on fluorinatedamphiphilic triblock copolymer based on PIB and polystyrene: synthesis, characterization,solution properties and its application in the field of super hydrophobic materials.Part I: PIB-b-PDMAEMA-b-POFPMA SystemWe first prepared PIB-OH containing hydroxyl group at the end of polyisobutene byborohydride oxidation reaction of highly reactive polyisobutene HRPIB. Then wesynthesised amphiphilic block polymer PIB-b-PDMAEMA-b-POFPMA by two-stepoxyanion-initiated polymerization (OIP). We verify the chemical structures of the polymer,molecular weight and molecular weight distribution by1H NMR,13C NMR,19F NMR,GPC and FT-IR. The thermal stability and glass transition temperature of the polymerswere studied by TGA and DSC researches. The self-assembly behaviors of the polymer inthe water under different conditions were studied by TEM. Different morphologies such asmulticompartment micelles, fibrous aggregates, tube, rod, etc. were obtained, whichindicated that the self-assembly of polymer morphologies and sizes were dependent on thecomposition of polymer concentration and pH value. Through the water contact anglemeasurement, we found that the polymer have hydrophobic and oleophobic property. Westudied the properties of polymer film by AFM, SEM and XRD. Part II: PS-b-PDMAEMA-b-POFPMA SystemAfter the research of the first part, we found that the triblock polymerPIB-b-PDMAEMA-b-POFPMA can self-assemble into a variety of morphologies, wesuspect the flexible chain PIB played a key role in the process of self-assembly behavoirs.So we changed the flexible chain PIB into rigid chain of PS to compare two differentself-assembly behaviors. Similarly, we prepared the triblock polymerPS-b-PDMAEMA-b-POFPMA by OIP using PS-OH as the initiator. We validated thechemical structure of polymer, molecular weight and molecular weight distribution by1HNMR and GPC. We found that the PS-b-PDMAEMA-b-POFPMA could self-assemble intosmall multicompartment micelles, layer-staggered accumulation and flower-like micelles,demonstrating that the flexible chain and rigid chain play a big role in the process ofself-assembly.