FLAME RETARDANT INTUMESCENT POLYAMIDE11/COPOLYAMIDE NANOCOMPOSITES

摘要

Polyamide (PA) 11 and 12 are currently the most widely used polymeric materials in thernSelective Laser Sintering (SLS) rapid manufacturing (RM) process. However, these polymersrnlack of flame retardancy and high strength/high heat resistance characteristics for a plethora ofrnfabricated parts that are desired and required for performance driven applications. It had beenrnreported that enhanced thermal, flammability, and mechanical properties (except elongation atrnrupture) of these polymers were obtained by nanomodifying them with nanoparticles such asrnMMT clay and carbon nanofibers (CNFs). Furthermore, truly flame retardant (FR) polyamiderncan be fabricated when intumescent FR additives are incorporated in addition to thernnanoparticles. However, the mechanical properties of such PA11 FR nanocomposites suffer duernto the addition of micron-sized intumescent FR additives, especially on the tensile elongation atrnrupture. Therefore, the objective of this study is to toughen these FR nanocomposites byrnintroducing a third element, Arkema’s Platamid? copolyamide.rnIn the present study, a nanophase was introduced into the polyamide 11 and combining it with arnconventional intumescent FR additive and a coployamide via twin screw extrusion. ArkemarnRILSAN? polyamide 11 molding polymer pellets were examined with chemically modifiedrnmontmorillonite (MMT) organoclays; Clairant’s Exolit? OP1312 intumescent FR additives; andrnArkema’s Platamid? copolyamide were used to create a family of FR intumescent polyamidern11/copolyamide nanocomposites.rnTransmission electron microscopy (TEM) is used to determine the degree of nanoparticlesrndispersion. Injection molded specimens are fabricated for physical and flammabilityrnmeasurements. Flammability properties are obtained using the UL 94 test method. Mechanicalrnproperties are investigated by performing tensile and impact tests. TEM micrographs, physical,rnand flammability properties are presented. FR intumescent PA11/copolyamide nanocompositesrnproperties are compared with PA11 baseline polymer. Based on flammability and mechanicalrnmaterial performance, selective polymer blends including PA11/copolyamide nanocompositesrnand control PA11 will be cryogenically ground into fine powders for SLS RM processing. SLSrnspecimens will be fabricated for physical, thermal, flammability, and mechanical propertiesrncharacterization.