| The challenge of improving the mechanical and thermal properties of semi-crystalline polymers continues to receive considerable interest. Among the effective methods particulate polymer composites represent growth sector in industry due to their competitiveness in terms of cost and performance. The properties of particulate composite are influenced by many factors such as filler characteristics, filler content, interfacial adhesion, and etc. One common purpose for adding mineral fillers to polymers is cost reduction. Fillers have also been used increasingly to fulfill additional roles, such as enhancing stiffness, decreasing dielectric loss or increasing absorption of infrared radiation. The mechanical and thermal properties of composites are strongly dependent on the reinforcement and interfacial compatibility of the composite system. The characteristics of particulate filled polymers are determined by the properties of their components, composition, structure and interactions. A possible way for the improvement of composite properties is the modification of interfacial interactions either through changing the size of the interface or through altering the strength of the interaction, and the surface treatment is the obvious way to modify interaction. Particulate filled polymers are prepared by melt mixing of the components, thus the major attractive and separating forces must be considered under these conditions. And also the surface properties of the fillers are concerned in thermal compounding. Therefore, the application of some coupling agents in particulate filled polymer have generally been directed to overcome the dispersion problem and to enhance the mechanical strength of composites by improving adhesion across the interface and thus upgrade the performance of composites.The presence of these interfaces then alters the crystallization process of the matrix, resulting in the formation of layers of oriented crystalline material endowed with reduced plastic shear resistance around the particles. And the particle can act as a nucleating agent for crystallization or decrease the crystallinity by introducing kinetic hindrance. Calcium carbonate is a common filler that can be obtained in a variety of sizes and surface treatment. Many types of specially precipitated calcium carbonate filler particles have relatively regular, nearly equiaxed shapes. PEEK is a semi-crystalline, high performance thermoplastic with Tg of 143oC and Tm of 334oC. Its superior mechanical properties and excellent resistance to hydrolysis and thermal stability have resulted in its extensive usage as structural and load bearing materials in the aerospace and marine industries.In this study, calcium carbonate particles were incorporated into poly ether ether ketone(PEEK) for potential use in major load bearing applications and biomaterial field. The temperature of the compounding of PEEK with inorganic fillers was above 350oC, under which most of the common coupling agents are not suitable to this compounding system. Therefore, an attempt was made to find a new type of coupling agent based on PEEK applied in this composite system, and it was found that sulfonated PEEK (SPEEK) can offer active groups of –SO3H in the backbone of PEEK. Treatment with SPEEK can effectively modify the dispersion of the calcium carbonate particles in the PEEK matrix, and a surface layer between the fillers and the matrix can also influence the behavior of the polymer chains. CaCO3/PEEK (Poly ether ether ketone) composites were prepared on a twin-screw extruder with different mass ratio of CaCO3/PEEK from 0-30%. The influence of surface treatment with sulfonated PEEK(SPEEK) of the particles on the mechanical and thermal properties of the composites was studied. And the melting rheology behavior of CaCO3/PEEK composites was also investigated. The experiments included tensile tests, flexural tests, notched Izod impact tests, TGA, DSC, SEM and dynamic melting rheology tests. The modulus and yield stress of the composites increased with...
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