ISSN:
1435-1536
Keywords:
Key words Polymer blends
;
Thin films
;
Topography
;
Polystyrene
;
Molecular weight
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Blends of polystyrene and poly(4-bromostyrene) phase-separate during spin-casting onto silicon wafers to give a thin film with islands of poly(4-bromostyrene) in a sea of polystyrene. Variation of the molecular weights of the blend components shows that the poly- (4-bromostyrene) and polystyrene influence the film structure in different ways. For poly(4-bromostyrene) of a given molecular weight, the ratio of the observed feature height to the overall film thickness remained constant as the film thickness increased. Moreover, the mean height of the topographical features was independent of the polystyrene but decreased with the molecular weight of the brominated polymer. It is concluded that the substrate–poly(4-bromostyrene) interaction dominates the formation of topography and consequently, though the islands are poly(4-bromostyrene), the mean height of the topographical features is greater the lower the molecular weight of the brominated polymer. The polystyrene has a secondary role, altering the thermodynamics or viscosity of the blend, thereby controlling the number of islands formed: the higher the molecular weight of the polystyrene the greater the number of islands.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003960000359
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