Cellulosic filled plastic systems

The advanced applications for nitrocellulose plastisol propellants require that they be integrally bonded to the motor case. Successful case bonding for the multiyear storage life of a rocket calls for special adhesives and liners which are completely compatible with these highly plasticized propellants. Best results have been obtained with a combination of an impervious rubber liner and a crosslinked adhesive system with a limited affinity for the plasticizers used in the propellants. Examples of effective liners are silica-filled butyl rubber and chlorinated synthetic rubber. Epoxy polyamides, isocyanate-crosslinked cellulose esters, and combinations of crosslinked phenol-formaldehyde and polyvinyl formal varnishes have proved to be effective adhesives between propellant and impervious liners. Pressure curing of the propellants helps... 

Povidone can also be used as a hydrophilic component or pore former in preparations that contain sustained-release auxiliaries like polyvinyl acetate, cellulose derivatives like HPMC [490, 509, 660], alginate [461], cetylacohol [600], polylactic acid [5o6],Gelucire [510],polyvinyl alcohol [522],ceresine wax [523], stearic acid [606] or methacrylate copolymers [491] to control or regulate the release of active substances, as binders and/or sometimes as plasticizers. They can also be extruded together with the active substance in melted stearyl alcohol and filled into hard gelatin capsules to achieve the same effect [471]. Ocular delivery systems are also described [598]. 

Vervaet et al. investigated another example of a core-sheU microcapsule system via HME technology in 2005. 2 These researchers used HME as an alternative technique for enteric delivery. Polyvinyl acetate phthalate and hydroxypropyl methyl cellulose acetate succinate (HPMC AS) enteric coating polymers were premixed with plasticizers and extruded into hollow cylinders. A model drug was then filled into these hollow cylinders and both open ends were sealed. Dissolution... 

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