Effectiveness of silane treatment on absorbable microfibers.
Preliminary experiments suggest pretreatment of absorbable crystalline, calcium-sodium-metaphosphate (CSM) microfibers with trimethoxy-based silane coupling agents yields a polysiloxane film barrier which protects the fiber surface from early dissolution due to water.  Compared to thermoplastic poly(L-lactic acid) (PLLA) composites reinforced with untreated fibers, PLLA composites reinforced with a variety of silane pretreated microfibers showed increased mechanical properties, suggesting improved adhesion was achieved at the fiber/matrix interface.  Unfortunately, the silane pretreated CSM/PLLA composite showed no increase in wet strength retention after short-term in vitro exposure.  This may be due to plasticization from water entering the composite at areas of incomplete fiber wetting by the highly viscous molten PLLA.  However, when a nonabsorbable, low viscosity unsaturated polyester thermoset resin was reinforced with methacryloxy-silane pretreated CSM microfibers, there was no decrease in flexural strength and less than a 10% decrease in flexural modulus after 7 days exposure to 7.4 pH Tris-buffered saline at 37  degrees C.
Orthopedic Bioengineering Laboratory, Division of Orthopedic Surgery, University of Utah School of Medicine, Salt Lake City.
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Andriano
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Daniels
D001673:Biodegradation, Environmental; D002130:Calcium Phosphates / Q000737:chemistry*; D003188:Composite Resins; D005898:Glass; D006801:Humans; D007773:Lactates / Q000737:chemistry; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry; D012821:Silanes / Q000737:chemistry*; D013499:Surface Properties; D013718:Tensile Strength