Die Makromolekulare Chemie · 1991 · 12 citations · 5 references
Macromolecular ChemistryEngineeringPolymer NanocompositesChemistryPolymersChemical EngineeringPolymer MaterialMacromolecular EngineeringPolymer ProcessingPolymer ChemistryMaterials SciencePdms ContentSelf CondensationBlock Co-polymersSelf-assemblyPolymer ScienceAbstract PolystyrenePolymer CharacterizationPolymerization KineticsWell‐defined Multiblock CopolymersPolymer Synthesis
Abstract Polystyrene (PS)‐polydimethylsiloxane (PDMS) triblock copolymers with well‐defined block lengths and silanol reactive end‐groups were synthesized by anionic polymerization as prepolymers for condensation reactions. Multiblock PS‐PDMS copolymers characterized by molecular and chemical homogeneity could be obtained either by self condensation of the silanol groups of by reaction with dichlorodimethylsilane. The kinetic constants, the activation energy, the extent of reaction and the molecular characteristics of the multiblock copolymers were determined as a function of the molecular weight of the prepolymer, the water content of the reaction medium and the concentration of HCl acting as catalyst in the dehydration reaction. The kinetic constants and the ultimate extent of the reaction could be correlated to the molecular weight of the prepolymer and to the viscosity of the reaction medium. DSC measurements of the multiblock copolymers show clearly the presence of two‐phase materials with mechanical properties depending on the PDMS content.
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