Characterization of Thermoplastic Blends as Binders for Ceramics

Abstract

Molded ceramics with simple poly(ethylene-ethylacryate) thermoplastic binders suffer severe distortion during heating associated with relaxation of polymer conformations, but blends of poly(ethylene-ethylacrylate) containing poly(isobutyl methacrylate) resins and polyethylene glycol and mineral additives do not suffer distortions. The polymer blends are characterized using polarized light microscopy and thermal analysis. Crystallinity and spherulite size of the binder are reduced by blending and by the addition of ceramic powder. Plasticizer additives polyethylene glycol and mineral oil phase separate in poly(ethyleneethyacrylate), but are compatablized by additions of poly(isobutyl methacrylate). The compatibalized plasticizers are able to relax the polymer conformations after molding, avoiding distortion on subsequent heating. J ournal

Aligning α‐alumina platelets via uniaxial pressing of ceramic‐filled polymer blends for improved sintered transparency

“…Many of these samples would crumble during removal from the warm pressing surfaces. However, samples made with equiaxed (AA03) powders were able to reach higher solids loading and maintain polymer‐like properties, which is similar to what is observed in the literature for EEA‐based systems . The use of platelet morphology powders is clearly influencing the behavior of the blends.…”

“…Figure shows that an increase in the solids loading led to an increase in the measured torque for the different platelet blends. This trend is commonly observed in similar ceramic‐filled polymer blends developed for coextrusion and green machining processes . A study focusing on the rheological behavior of BaTiO 3 /EEA blends found that an increase in solids loading increased the torque and viscosity values at a constant temperature .…”

“…A thermoplastic binder system was modified and adapted from previous work on the coextrusion of fibrous monoliths and green machining . The development of the system and individual functions of each component is described in detail in the literature . A four‐component polymer blend consisting of EEA (MFI = 6.0 g/10 min, poly[ethylene‐co‐ethyl acrylate], Dow Elastomers, Midland, MI), PiBMA (poly[ethylene‐co‐butyl acrylate], Acryloid B67, Rohm and Haas), poly ethylene glycol (PEG1300, Mw = 1300 g/mol, Sigma‐Aldrich), and HMO (heavy mineral oil, Fischer Chemical, Hampton, NH) was selected.…”

“…However, ceramic‐filled thermoplastic polymer blends have been used by the fibrous monolith and coextrusion community for some time . Many of these processes have taken advantage of the shear and elongational stresses developed during forming to align anisotropic powders.…”

“…The present study aims to produce axisymmetric‐aligned platelet alumina in ceramic‐filled thermoplastic polymer sheets via uniaxial warm pressing. The blends were modified from compositions of poly(ethylene‐co‐ethyl acrylate) (EEA) found in the literature . This was done via plasticizer additions and acrylate reductions, resulting in desirable flow properties and greater formability.…”