Morphology development of physical polymer mixtures in sintering based processing technologies

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Polymer sintering technologies are used to manufacture parts of dimensions ranging from metres to microns, with simple or complex structures, based on the melt coalescence of powders. Rotational molding is the more mature technology in this area where 3D printing by selective laser sintering is still emerging. Both methods form products that are often difficult or impossible by other polymer processing approaches. However, the absence of shear stresses in both has created limitations on the materials selected with these technologies, which has in turn kept them out of markets reliant on more advanced properties. North America has the largest concentration of rotational molding manufacturers globally and 3D printing methods are considered integral to Canada's high technology economy, making both strategically important to our manufacturing sector. It is beneficial to Canada that we advance their capabilities to complete in market sectors where more advanced properties are demanded. Broadening the properties to satisfy the needs of new applications, mixtures of polymers are often combined to form complex phase morphologies. Stable blend morphologies of two or more polymers are commonly produced in the presence of shear and elongational stresses. With an absence of shear stresses, the options for rotational molding and selective laser sintering (SLS) are only to use pre-compounded materials, which add considerable costs, or to consider a poorly understood alternative where physical mixtures of polymers are sintered to form a blend. This proposal will increase the industry's understanding of this less expensive alternative by sintering a physical mixture and will compare its findings to pre-compounded materials. The goal of the studies is to identify approaches whereby desirable blend morphologies arise by controlling composition, viscosity ratio, resin compatibility, crystallinity and particle packing density. The intent is to deliver a statistical model which the industrial sponsor and others may use to predict final properties as they are related to the morphology formed.