ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
A novel azo-initiator, 2-[(2-ethylphosphatoethyl)dimethylammonio]ethyl 4,4′-azobis-(4-cyanovalerate) (EAP-501), was prepared. EAP-501 [m. p. 97°C (dec.), λmax 346 nm in H2O] was found to be amphiphilic, with a Krafft point of 11,5°C and a critical micelle concentration of 47,2 mmol·dm-3 at 30°C and 48,6 mmol·dm-3 at 70°C. The rate and activation parameters for the thermal decomposition of EAP-501 at 70°C were estimated to be kd = 2,35·10-5 s-1, ΔH≠ = 118,4 kJ·mol-1 and ΔS≠ = 10,5 J·mol-1·K-1. Emulsion polymerization of styrene initiated with EAP-501 gave polymer microspheres in high yield. The resulting polystyrene microspheres were characterized by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The polystyrene microspheres have diameters from 321 to 649 nm by varying the EAP-501 concentration. The ammonium phosphate groups, which are comparable to the polar head group of phospholipids, are concentrated on the surface of the particles. The particles were found to reduce the adsorption of bovine serum albumin (BSA) compared with particles prepared by the emulsion polymerization of styrene initiated with potassium persulfate as an initiator.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1994.021950418
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