title: Encapsulation of a pressure-sensitive adhesive by spray-drying: microparticles preparation and evaluation of their crushing strength.
abstract: An industrial pressure-sensitive adhesive was microencapsulated by spray-drying using an aqueous colloidal ethylcellulose dispersion (Aquacoat® ECD) plasticised by triacetin to form the wall material. Unloaded (0:100) and adhesive-loaded (25:75) particles were produced in a Büchi B-191 mini spray-dryer with product yields of 62% and 57%, respectively. Microparticles were spherical and narrow sized with mean D₃,₂ diameters of 3.165 ± 0.001 and 5.544 ± 0.105 µm, respectively. The microparticles were found to redisperse well in water and exhibit enough stability in neutral and alkaline aqueous media to be further used in a coating slip. Crush tests on single microparticles with diameters ranging from 2 to 12 µm were performed using a nanoindenter. They revealed that the crushing force of both kinds of microparticles increased linearly with their diameter and that the adhesive loading reduced the mechanical strength of the prepared microparticles.
authors.affiliation: Université de Lyon, F-69622, Lyon, France. gavory@lagep.univ-lyon1.fr
authors.forename: Cécile
authors.initials: C
authors.lastname: Gavory
authors.forename: Robin
authors.initials: R
authors.lastname: Abderrahmen
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Valour
authors.forename: Didier
authors.initials: D
authors.lastname: Chaussy
authors.forename: Mohamed Naceur
authors.initials: MN
authors.lastname: Belgacem
authors.forename: Hatem
authors.initials: H
authors.lastname: Fessi
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Briançon
mesh_terms: D000269:Adhesives; D001696:Biomechanical Phenomena; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D010316:Particle Size; D011312:Pressure
chemical_list: D000269:Adhesives; C013517:ethyl cellulose; D002482:Cellulose