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The thermal and rheological properties of a series of poly- (dimethylsiloxane-co-methylalkylsiloxane) (PDM-PMAS) copolymers containing 3.5 mol % methylalkylsiloxane units of various alkyl lengths were investigated. Calorimetric results show that the alkyl side chains are crystallizable. The side-chain melting temperatures and heats of fusion normalized for side-chain weight fraction increased with increasing side-chain length. The steady-shear melt viscosity of the polymers with C10, C12, and C14 side chains decreased with increasing side-chain length. Low-strain oscillatory measurements indicated the formation of a network structure at room temperature for polymers with C16 and C18 side chains, which can be attributed to intermolecular crystallization of the paraffinic side chains. POLYSILOXANES WITH PENDANT SIDE CHAINS are interesting materials fromboth the theoretical and practical points of view. A number of polysiloxanes with various side chains, such as liquid crystals (J, 2), carbazole groups (3), electron-donor and electron-acceptor groups (4), polystyrene (5), and functional groups (hydroxyl or carboxyl) (6), have been synthesized. Polysiloxanes are known for their useful properties, which include flexibility, heat resistance, water repellence, and biological inertness. These properties, combined with the ease with which a tailored polymer structure can be prepared, J

SynopsisThe water solubility characteristics of a series of ionic copolymers of acrylic acid with acrylic esters was determined. A relationship was developed between solubility and the ionic character of the copolymers. In addition to water solubility, the effects of the composition and degree of neutralization upon other copolymer properties were also examined. Moisture effects upon the physical properties can be minimized by limiting the ionic character of the copolymer to that required for water solubility. The effects of molecular weight on the solubility and speed of dissolution was also investigated and found to have no effect, within the range of composition of the copolymers investigated.