Thermosensitive permeation from side-chain crystalline ionomers

Abstract

Poly(stearyl methacrylate‐co‐methacrylic acid) (SMA) and its sodium ionomer (SMI) were synthesized and the permeability of the model drug through the SMA and SMI films was measured. The side‐chain crystalline structure for the dried and hydrated SMA, SMI was investigated using DSC and WAXS. The side‐chain crystalline structure of the hydrated SMI was much more stable than that of the hydrated SMA at room temperature. The temperature‐sensitive phase transition of the side‐chain crystalline structure for the hydrated SMI was also studied by the temperature variable WAXS experiment. The temperature‐sensitive permeation of the hydrophilic model drug through SMI was observed around 20 °C, whereas the drug permeation through SMA was almost constant within the temperature range studied. The change of drug permeability through the SMA and SMI films with temperature seems to be associated with the side‐chain crystalline structure of the polymer. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 823–830, 2000

Triple Function Lubricant Additives Based on Organic–Inorganic Hybrid Star Polymers: Friction Reduction, Wear Protection, and Viscosity Modification

“…The thermograms of all p­(SMA- co -MMA) derivatives revealed broad endothermic and exothermic signals at ∼25 and ∼10 °C, respectively (Figure S9a). We hypothesize that the observed broad melting peaks are the result of SMA crystalline domains perturbed by the random incorporation of the shorter MMA side chains. − This was corroborated by synthesizing and measuring the thermal properties of an inorganic–organic hybrid star polymer containing p­(SMA) homopolymer arms (employed initiator = IC-9). In contrast to the weak melting signals obtained for the SMA- co -MMA copolymers, a sharp melting transition was observed for the p­(SMA)-based star (Supporting Information S2, Figure S9, yellow traces).…”

Surface-Modification of Polyelectrolyte Multilayer-Coated Particles for Biological Applications

“…A sharp endothermic peak for pure ODA was obtained at 50.7 °C (Figure ), corresponding to its melting temperature. The higher transition temperatures obtained for the ODA-grafted particles may be due to increased inter- and intramolecular interactions between the octadecyl chains in the presence of water . The DSC thermograms indicate the presence of a stable octadecyl phase after grafting.…”

“…The higher transition temperatures obtained for the ODA-grafted particles may be due to increased inter-and intramolecular interactions between the octadecyl chains in the presence of water. 18 The DSC thermograms indicate the presence of a stable octadecyl phase after grafting. These results are consistent with those reported for other octadecyl-grafted comb polymers in an aqueous solution.…”

Templated Ultrathin Polyelectrolyte Microreservoir for Delivery of Bovine Serum Albumin: Fabrication and Performance Evaluation

“…It is well-known that assembling layer by layer along with closely packed hydrophilic, hydrophobic chains followed by exposure to aqueous solution provides hydrophilic brushes on the surface (30). The higher transition temperatures as observed in DSC thermograms obtained for cross-linked UPM might be attributed to increased inter-and intramolecular interaction between the hydrophilic-hydrophobic chains in presence of water (31).…”