Inversion of Phase Morphology in Polymer‐Blend Thin Films on Glass Substrates

Abstract

Summary: The phase‐morphology inversion in two blend systems of polystyrene/poly(methyl methacrylate) (PS/PMMA) and polystyrene/poly(ε‐caprolactone) (PS/PCL) has been studied after their thin films were prepared on glass substrates by spin‐coating from a co‐solvent tetrahydrofuran (THF). Phase‐contrast microscopy (PCM), scanning‐electron microscopy (SEM) equipped with energy dispersive X‐ray spectroscopy (EDS), and atomic force microscopy (AFM) were used to obtain information on the morphology of the thin films during heat treatment. It was found that the PMMA‐rich and PCL‐rich phases are always continuous after annealing in either of the PS/PMMA and PS/PCL blend thin films, even though the PMMA and PCL are minor components in the blends. This should result from the better wetting abilities of PMMA and PCL on a glass substrate than PS in the blends. The effect of the viscosity in the evolution of the phase structure was also investigated by changing the molecular weight of PS in the PS/PCL blend thin films. Further more, it is found that the phase‐separation process and the wetting phenomenon of the blends on the glass substrate can be strongly suppressed after adding PS‐block‐PMMA diblock copolymer to the PS/PMMA blend system as a compatibilizer.Scheme of the longitudinal section of the evolution of the phase structure of a PS:PMMA (70:30 w:w) blend film.imageScheme of the longitudinal section of the evolution of the phase structure of a PS:PMMA (70:30 w:w) blend film.

Preparing iPP/HDPE/CB functionally gradient materials: influence factors of components and processing

“…The effect of molecular weight on the blends' gradient structure is reflected by the relation of the molecular weight and polymer viscosity 37. Zong et al38 studied the influence of component viscosity on the development of phase morphology by blending the different molecular weight of polystyrene (PS) and poly(ε‐caprolactone) (PCL), and found that the lamella structure of compound developed slower with increasing viscosity of PS. The movement and diffusion of molecular chain become difficulty with increasing molecular weight of polymer.…”

Synthesis, characterization and performance of polystyrene/PMMA blend membranes for potential water treatment

“…It can be suggested that in the initial stages of the phase inversion process, fast precipitation of the PS occurs. PS separates from PMMA and solidifies as a PS-rich phase, while the PMMA phase collapses below the PS-air interface [43]. In the later immersing stage, increase in the water inflow results in a secondary polymer-rich/polymer-lean phase separation [44].…”

Ultrathin film crystallization of poly(ε-caprolactone) in blends containing styrene-isoprene block copolymers: The nano-rose morphology

“…Just as the magnitudes of surface interactions between polymer components and between the polymers and the substrate are principle considerations in morphology development, the surface area of interaction is equally important. Experimentally, the interfacial area between blend components is determined by blend composition through its influence on domain sizes [2,41,49,50]. To study and quantify the blend compositions where nano-rose formation is possible, film thickness gradients of 45 kDa PCL/SIS vector 4293A blends with compositions ranging from pure PCL (0% SIS) to pure SIS (100% SIS) were flow coated from toluene.…”