Mechanical properties, CaCO

Non-reinforcing fillers (passive) Ground calcium carbonate (CaCO ) Reduce formulation cost adjust rheology, and mechanical properties. 

Nucleating agents not only shorten the time of crystallization but also improve the mechanical properties of materials. Polypropylene processed with a nucleating agent (2% CaCOs) had its impact strength and modulus increased by 50%. ... 

The results of a study of the relation between the oriented structure and drawn poly(e-caprolactone) specimens including CaCO particles, their dynamic mechanical properties and line shape analyses of CP MAS NMR spectra are presented. Solid state studies of C NMR study of poly(methyl acrylate) ionomer have been reported. ... 

Ma,C.G. Mai, Y.L. Rong, M.Z. Ruan, W.H. Zhang M.Q. (2007). Phase structure and mechanical properties of ternary polypropylene/elastomer/nano-CaCOs composites. Composites Science and Technology, vol.67, No.l4, pp.2997-3005, ISSN ... 

Reinforcing fillers (active) Fumed Silica (Si02) precipitated calcium carbonate (CaCOs) carbon black Thixotropic reinforcing agents (non-slump), adjustment of mechanical properties (cohesion) provide toughness to the elastomer as opposed to brittle materials. 

Inorganic nanoparticles like Al O, ZnO, TiO, CaCO, and SiO are widely used as reinforcement for the polymers to enhance their physical and mechanical properties [6,30-35]. 

The TiO nanoparticles can be modified by vinyltrimethoxysilane for dispersing in polyethylene matrix [37]. In a similar manner, the SiO nanoparticle is modified by the 3-aminopropyltrimethoxysilane and 3-glycydyloxypropyltrimethoxysilane to improve the mechanical properties [38] and fractme toughness [39] respectively. ZnO nanoparticle is modified by 3-(trimethoxysilyl) propyl methacrylate (TPMA) surfactant [34]. Researchers have also modified the CaCO nanoparticle with stearic acid to improve the compatibility with the polypropylene matrix [30,40]. 

The pre-treatment of a filler surface changes fhe interface, and thus it is expected to affect the properties of adjacent phases extending some way into the bulk. There are examples of using the various surface modifiers such are acids and acid precursors, alkoxysilanes, organofitanates and related compounds, stearic acid and others." How the surface pre-treatment of CaCOs filler by sodium stearate changed fhe adhesion parameters in the PVAc composite is illustrated in Table 1 The adhesion parameters could be used to relate the interactions at the interface to the mechanical properties of the composite. For example, the small absolute decreases in the work of adhesion after the pre-treatment can lead to the proportionate large absolute decreases in fracture energy. 

Zhou and co-workers [27] studied the effect of surface treatment of calcium carbonate with sulfonated PEEK on the mechanical properties of the polymer. Tests used included tensile tests, flexural tests, notched Izod impact tests, TGA, DSC and SEM. The modulus and yield stress of the composites increased with CaCOs particle loading. This increase was attributed to the bonding between the particles and the PEEK matrix, was proved by the SEM of the tensile fracture surface of the composites. The treated fillers were found to give a better combination of properties, which indicated that the sulfonated PEEK played a constructive role in the calcium carbonate/PEEK composites. 

The effect of the concentration on the mechanical properties can be observed from Figures 10-13. All fillers show qualitatively similar results, namely, the mechanical properties increase up to a content of about 20% then remain constant or decrease. Concentrations of CaCOs and sawdust as high as 20% are economical considering a very low cost of these materials, whereas more expensive glass fibers can be used at a level of 10% to remarkably improve the mechanical properties at low cost. 

Other systems were also selected, considering mechanical properties, processability, and cost of additives. In particular, CaCOs is an inexpensive filler, PE-g-MA and OCT/CH are also relatively inexpensive, and give some improvement of the mechanical properties. EPDM is quite expensive but it contributes to a remarkable enhancement of elongation at break and impact strength. 

Recently, PVDF has been intensively studied by many authors as a polymer matrix for ceramic nanopowders such as BaTiOs [212,214-216], PbTiOs [217], CaCOs [218], and Pb(Zro.5TiOo.5)03 [215] because they combine the excellent ferroelectric properties of ceramics with the flexible mechanical properties of the polymer. The PVDF polymer composites with electroactive ceramic nanoparticles were prepared by sol-gel processes [214,217], a natural adsorption action between the nanosized BaTiOs and PVDF particles, and then a hot press process [216]. 

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