CaCO3 Filler Research Articles

Controlled CaCO3 stearate pre-treatment effects on the interphase adhesion in filled SAN/EPDM blend

Calcium carbonate (CaCO3) fillers pre-treated with the increased amount of stearate were used in order to tune the surface energy for a selective filler migration to the interface in immiscible styrene-acrylonitrile/ethylene–propylene–diene (SAN/EPDM) polymer blends. Various models were used in order to predict the filler accommodation at the blend interface when the interfacial tension becomes low and the wettability is good. The results showed that under optimal thermodynamic conditions, the filler might act as a compatibilizer and significantly improve the blend morphology. The coarse morphology of the initially immiscible SAN/EPDM changed into a fine blend morphology with the addition of the selected CaCO3 fillers with optimal surface energy. Due to the problem with filler agglomeration of initially nanosized CaCO3 fillers, we used masterbatch (MB) compositions for the blend preparation in order to get the better filler distribution. In this paper, the comparison between two types of MB compositions based on SAN and/or EPDM as a surplus phase with the selected filler was made considering the model predictions and its effects on the blend morphology and properties. In the case of using MB(EPDM) in blend preparation, the fine blend morphology resulted in improved mechanical and thermal properties, while with MB(SAN) the coarse blend morphology and worsened properties illustrated the opposite effect.

Effect of Pre-flocculation of Lime Mud CaCO3 Filler on AKD Sizing Efficiency

Lime mud (LM), whose main component is calcium carbonate, is a by-product in the pulp and papermaking industry. For non-wood pulping processes, large amounts of LM are produced every year, and a portion of them has been used as a paper filler. However, LM significantly lowers alkyl ketene dimer (AKD) sizing efficiency when added to paper. In this study, LM slurry was first pre-flocculated using some commonly used wet-end additives; then, the pre-flocculated LM was added to the pulp for handsheet preparation. The effect of LM pre-flocculation on AKD sizing efficiency was investigated by means of Cobb60 value, contact angle, and sizing reversion. Finally, the AKD adsorption, particle size, BET surface area, BJH pore volume, and zeta potential of native and pre-flocculated LM were measured. It was found that handsheets filled with pre-flocculated LM had lower Cobb60 values and larger contact angles compared to handsheets filled with native LM. The sizing reversion was also alleviated to a certain extent. This was probably because the BET surface area and BJH pore volume of pre-flocculated LM were lower than native LM and the zeta potential was higher than native LM, which led to a much less adsorption of AKD. Thus, AKD sizing efficiency was significantly improved.

Bio-based polyolefin composites and functional films for reducing total carbon footprint

The utilization of bio-based renewable and sustainable materials for industrial application is pursued aggressively by multiple research entities and manufacturing companies. Effective sequestration of CO2 by sugarcane plantation as a first step, which is then converted to green polyolefin, reduces greenhouse gases effect on global warming. This article addresses bio-based polyethylene composites and functional films for flexible packaging and personal care product applications. The bio-based polyethylene composite films, obtained by melt compounding of thermoplastic cross-linked starch as filler for film casting, show relatively low film modulus, peak stress and total energy to break even at a high level of filler inclusion. In comparison, petroleum-based polyethylene filled with CaCO3 exhibits unusually high film modulus and total energy absorption except for film peak stress. The bio-based polyethylene composite film elongation ranges from 829% for the neat bio-based polyethylene to 522% for the film containing 30% thermoplastic cross-linked starch, whereas petroleum-based polyethylene composite films as a control show relatively small changes in film elongation with and without CaCO3 filler. The scanning electron microscopy results revealed a majority of filler is in micrometer sizes in the bio-based PE composite films and an open porous network existed for breathable films containing CaCO3 as filler.

Effects of CaCO3 and Kaolin Filler Loadings on Curing Rates of Polyurethane Foams

Commercial kaolin (Al 2Si2O 5(OH)4),a clay mineral obtained on the Upper Plateau (Jos, Central Nigeria) was characterized for physical properties such as moisture content (= 1.30%), sieved particle size (= 150µm) and (Apparent Bulk Density (= 0.40g/cm 3 ) and compared to CaCO 3, a rock mineral and a conventional filler presently used extensively in the foam industry in Nigeria, with moisture content (= 0.60%), sieved particle size (= 150µm) and (Apparent BulkDensity (= 0.75g/cm

Thermal and Oxygen Barrier Properties of Chitosan Bionanocomposites by Reinforcement of Calcium Carbonate Nanopowder

Chitosan and calcium carbonate nanopowder (chitosan/CaCO3) bionanocomposites were prepared by solution method. Interaction between chitosan and CaCO3 was studied by Fourier transform infrared spectroscopy (FT-IR). Structure and surface morphology of chitosan/CaCO3 bionanocomposites were investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively. The energy dispersive X-ray spectroscopy (EDS) of chitosan/CaCO3 bionanocomposites was studied in order to establish the elements of composition. Thermal stability of prepared bionanocomposites was studied by thermogravimetric analysis (TGA) and a substantial increase of thermal stability of virgin chitosan was noticed due to incorporation of CaCO3 nanopowder. The oxygen permeability was reduced by three times as compared to the raw chitosan due to the dispersion of nano CaCO3 filler. Biodegradability and resistance towards dilute acid and alkali of the prepared bionanocomposite were investigated. The bionanocomposite having gas barrier and thermal stable property may be suitable for packaging and biomedical applications.

Influence of High-Density Polyethylene and Nano-Calcium Carbonate of Various Content Ratios on the Crystallization of Polypropylene

The influence of high-density polyethylene (HDPE) and nano-CaCO3 of various content ratios on the crystallization of polypropylene (PP) was investigated by differential scanning calorimetry, dynamic rheology, wide angle X-ray diffraction (WAXD), and Izod impact strength measurements. The results showed that HDPE and PP were phase separated in their blends and the additive CaCO3 filler mainly dispersed in the PP phase, acting as a nucleation agent to promote the crystallization of PP. For the samples HDPE/ nano-CaCO3 30/0 and 25/5, the β crystals content was much higher than the other samples. The reason is that the viscosity difference between HDPE and PP led to a velocity difference, which could induce shear stress at the interfaces of HDPE and PP during injection molding. The intensive shear stress at their phase interfaces is advantageous for orientation of the chains, inducing the formation of β crystals. However, with the increment of CaCO3 content, there were dual effects of CaCO3 on the crystallization of PP: at low CaCO3 content, it would hamper the orientation of PP chains, thus leading to a decrease of β crystals; at high CaCO3 content, it would induce β crystals by itself.

Effects of Calcium Carbonate on Melt Flow and Mechanical Properties of Rice Husk/HDPE and Kenaf/HDPE Hybrid Composites

In this research, calcium carbonate (CaCO3) was compounded with rice husk/high density polyethylene (HDPE) and kenaf/HDPE composite at different filler loadings to produce hybrid composites. Melt flow index (MFI) and mechanical properties of hybrid composite was investigated. From the test results, the addition of CaCO3 filler had decreased melt flow index (MFI) on both composites. In terms of mechanical properties, tensile strength, elongation at break and impact strength decreased, whereas Youngs Modulus increased with the increase of CaCO3 in both kenaf/HDPE and rice husk/HDPE composites. Impact strength of unfilled rice husk/HDPE composite was lower than unfilled kenaf/HDPE composite, however impact strength of CaCO3/rice husk/HDPE hybrid composite were found to have slightly higher than CaCO3/kenaf/HDPE hybrid composite with addition of 10% and 20% of CaCO3.

Effect of Calcium Carbonate on Thermal Properties of CaCO<sub>3</sub>/Kenaf/HDPE and CaCO<sub>3</sub>/Rice Husk/HDPE Composites

In this research, the thermal properties of 30% filler loading of natural fibers with varying filler loadings of calcium carbonate (CaCO3) were studied. CaCO3was compounded using twin-screw extruder with rice husk/high density polyethylene (HDPE) and kenaf/HDPE composites to produce composites. Compounded composites were prepared and tested for thermal properties. The thermal stability of the components was examined by thermogravimetric analysis (TGA) and differential scanning calorimetric (DSC) to identify the influence of CaCO3filler loading on thermal properties of the composites. The cycle heating for TGA was 30-800°C while for differential scanning calorimetric (DSC) was 30-300°C. Melting temperature (Tm) of kenaf/HDPE hybrid composites increased slightly with addition of 10% CaCO3. However, decreasing Tmwas found for all CaCO3filler loading in rice husk/HDPE composites. The DSC analysis showed that the degree of crystallinity (Xc) of hybrid composite decrease with the addition of CaCO3filler loading. From TGA result, CaCO3/kenaf/HDPE hybrid composite showed better thermal stability compared to CaCO3/rice husk/HDPE hybrid composite.

In vitro comparisons of casting retention on implant abutments among commercially available and experimental castor oil-containing dental luting agents

Although cement-retained implant prostheses are widely used, the quantification of optimal retention remains controversial, and new dental luting agents should be evaluated. The purpose of this study was to compare, in vitro, the casting retention on implant abutments after cementation with 3 commercially available luting agents and an experimental luting agent (castor oil polyurethane, COP) with variable weight percentages (wt%) of calcium carbonate (CaCO3). Seventy-two palladium-silver cast copings were fabricated and divided into 6 groups: Temp Bond interim cement (TB); zinc phosphate cement (ZP); Rely X ARC resin cement (RX); pure COP (COP); COP + 10% wt% CaCO3 filler (COP 10); and COP + 50% wt% CaCO3 filler (COP 50). After cementation, the specimens were stored in distilled water at 37°C for 24 hours and subjected to removal force tests in a universal testing machine (5 kN; 0.5 mm/min). Statistical analyses were performed with the Kruskal-Wallis and Student-Newman-Keuls tests (α=.05). The median values of casting retention (N) were as follows: TB=57.20 ±10.4; ZP=343.56 ±50.3; RX=40.07 ±9.7; COP=258.98 ±41.4; COP 10=466.57 ±79.3; and COP 50=209.63 ±31.4. The Kruskal-Wallis test showed significant differences among the groups (P<.01). TB and RX had the lowest mean retention values; COP, COP 10, and COP 50 were equal to ZP, and COP 10 had the highest retention. The casting retention on implant-abutments provided by COP was similar to that of copings cemented with zinc phosphate and may be influenced by the addition of calcium carbonate.

The Mechanical Properties of a Mixture of High Density Polyethylene and Calcium Carbonate Dedicated for Packaging

Packaging made of polymeric materials is one of the most important branches of polymer processing. A very essential task which is to be solved in this area, is searching for new materials which would allow for lowering the cost while still maintaining good mechanical properties. In the current paper the attempt to decrease the cost of the HDPE intended for blow moulding of packaging by admixing CaCO3 filler is presented. The dependence of mechanical properties upon the filler content is also shown.

Preparation of nanocoatings in the presence of precipitated CaCO3 fillers by UV-curing

Various methods were employed to prepare precipitated calcium carbonate (PCC) particles. Particle size and morphology were dependent on reaction conditions as well as temperature, reagents and stirring, either mechanical or by ultrasound probe sonication. Sonication helped to reduce the size of CaCO3 particles as well as the precipitation time. Sonication was also used to disperse PCC particles in the UV-curable formulations as well as for preparation of the PCC. Formulations containing precipitated calcium carbonates and ground calcium carbonates in various grades were cured by a Mini UV-Cure device. Mechanical and thermal properties of films were characterized with a Dynamic Mechanical Analyzer (DMA). SEM analysis was also used to determine the shape and the size of the PCCs. Sonication decreased the precipitation time of calcium carbonate at least four times more than that of conventional precipitation procedures and the dispersion of particles in the formulations increased to a great extent.

Mechanical and Dry Sliding Wear Behavior of Particulate Fillers CaCO&lt;SUB&gt;3&lt;/SUB&gt; and CaSO&lt;SUB&gt;4&lt;/SUB&gt; Filled Vinyl ester Composites

The imp roved performance of poly mers and their co mposites in industries and many other applications by the addition of part iculate fillers has shown great advantages and so has lately been the subject of considerable interest. In this paper, mechanical and tribological behavior of particu late fillers CaCO3 and CaSO4 filled v inyl ester co mposites have been presented. Wear tests were carried out in dry sliding conditions on a pin-on-disc friction and wear test rig. (DUCOM) at roo m temperature under slid ing velocity (1.57, 2.62 and 3.67 m/sec.), normal load (20, 40 and 60 N), filler content (0, 10 and 20 wt.%) and sliding d istance (1000, 3000 and 5000 m). The plans of experiments is based on the Taguchi technique, was performed to acquire data in a controlled way. An orthogonal array and analysis of variance (A NOVA ) were applied to investigate the influence of process parameters on the coefficient of friction and sliding wear behaviour of these composites. The coefficient of frict ion and specific wear rate were significantly influenced with increase in both the filler content. The results show that for pure vinyl ester the coefficient of frict ion and specific wear rate increases with the increase of normal load, sliding velocity and sliding d istance. The coefficient of friction and specific wear rate for CaCO3 filler decreases with the increase of filler content. But, for filler CaSO4 the coefficient of frict ion and specific wear rate decreases at 10 wt.% and then increases at 20 wt.%. It is believed that a thin film formed on stainless steel counterface was seems to be effective in improving the tribolog ical characteristics. The worn surfaces examined through SEM to elucidate the mechanis m of friction and wear behaviour.

Influence of Calcium Carbonate Fillers on the Properties of Recycled Poly(e-caprolactone) Based Thermoplastic Polyurethane

In this work the effects of different crystallographic modifications of calcium carbonate (CaCO3) filler on the melt flow, mechanical properties, hydrolytic degradation, and shape memory behaviour of recycled low-temperature poly(e-caprolactone)-based polyurethane (rTPU) were evaluated. Composites were prepared by two-roll milling varying filler content from 2 wt % to 6 wt %. It was found that at temperature range from 20 °C to 50 °C CaCO3 fillers do not change Young’s modulus, they decrease tensile stress and deformation of rTPU, but improve its mechanical properties at elevated temperatures (up to 65 °C). rTPU melt flow index increases due to chain scission during the recycling and filler mixing with mill. Therefore, destruction temperature of rTPU is 20 °C lower than that of TPU. The CaCO3 does not change shape memory properties independently of filler type and transition from secondary shape to the primary shape at 70 °C temperature is completed within 17 s for both filled and unfilled rTPU. The investigation of hydrolytic degradation shows that CaCO3 only slightly increases degradation rate of rTPU.DOI: http://dx.doi.org/10.5755/j01.ms.18.3.2433

Effects of BaSO4, CaCO3, kaolin and quartz fillers on mechanical, chemical and morphological properties of cast polyurethane

For industrial applications of engineering polymers such as polyurethane, polyamides and polyesters, the addition of suitable reinforcing inorganic fillers is a practical and convenient method to achieve the desirable mechanical and chemical properties. In this study, the mechanical, chemical and morphological properties of cast polyurethane samples containing barium sulphate, calcium carbonate, kaolin and quartz fillers were investigated. In the formulation of these samples, the ranges of inorganic filler were 0–40 phr. The results of mechanical property tests, such as tear resistance, tensile strength, elongation at break, Young’s modulus, hardness and abrasion resistance, were evaluated. The chemical resistance of the samples was determined against xylene and methyl ethyl ketone. The chemical resistance of the filled cast polyurethane was determined by the solubility parameters of polymer/solvent. Finally, the experimental results and SEM images showed that samples containing 30 phr calcium carbonate produced the best results.

Preparation and Characterization of N-Halamine-Based Antimicrobial Fillers

The purpose of this study was to demonstrate that the surface of CaCO(3) fillers could be coated with an N-halamine based fatty acid to make the filler surface organophilic and accomplish antibacterial activity simultaneously, rendering the resulting polymer-filler composites antimicrobial. Thus, a new bi-functional compound, 4, 4 -Dimethyl hydantoin-undecanoic acid (DMH-UA), was synthesized by treating the potassium salt of dimethyl hydantoin (DMH) with 11-bromoundecanoic acid (BUA). Upon chlorination treatment with diluted bleach, DMH-UA was transformed into 3-chloro-4, 4-dimethyl hydantoin- undecanoic acid (Cl-DMH-UA). Alternatively, DMH-UA could be coated onto the surface of CaCO(3) to obtain the corresponding calcium salt, 4, 4-dimethyl hydantoin-undecanoic acid-calcium carbonate (DMH-UA-CaCO(3)). In the presence of diluted chlorine bleach, the coated DMH-UA on the surface of CaCO(3) was transformed into Cl-DMH-UA, leading to the formation of Cl-DMH-UA-CaCO(3). The reactions were characterized with FT-IR, NMR, UV, DSC and SEM analyses. Both Cl-DMH-UA and Cl-DMH-UA-CaCO(3) were used as antimicrobial additives for cellulose acetate (CA). The antimicrobial efficacy of the resulting samples was evaluated against both Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria). It was found that with the same additive content, CA samples with Cl-DMH-UA-CaCO(3) and Cl-DMH-UA had very similar antimicrobial and biofilm-controlling activity, but the former released less active chlorine into the surrounding environment than the latter.

Preparation and properties of dynamically cured polypropylene (PP)/maleic anhydride–grafted polypropylene (MAH-g-PP)/calcium carbonate (CaCO3)/epoxy composites

In this study, an epoxy resin was dynamically cured in a polypropylene (PP)/maleic anhydride–grafted polypropylene (MAH-g-PP)/calcium carbonate (CaCO3) matrix to prepare dynamically cured PP/MAH-g-PP/CaCO3/epoxy composites. The torque measurement shows that the addition of epoxy resin into the PP/MAH-g-PP/CaCO3 composites results in a slight increase in the torque at equilibrium, and epoxy resin in the composites has been cured by 2-ethylene-4-methane-imidazole (EMI-2,4). Scanning electron microscopic analysis shows that dual compatibilizers composed of MAH-g-PP and an epoxy resin were demonstrated to effectively compatibilize the immiscible PP/CaCO3 composites. MAH-g-PP with a low MAH content is miscible with PP to make it quasi-functionalized, while the epoxy resin can react with MAH-g-PP and hydroxyl groups at the CaCO3 surface. Thus the formed MAH-g-PP-co-epoxy-co-CaCO3 copolymer at the interface is able to anchor along the interface and serve as an efficient compatibilizer. Dynamic cure of the epoxy resin can further increase the interaction adhesion in the PP/CaCO3 composites. The epoxy resin does not show compatibilization effects for the PP/CaCO3 composites without the presence of MAH-g-PP. The shift of crystallization peaks to the higher temperature suggests that the CaCO3 filler in the composites can act as a nucleating agent, accelerating the crystallization of PP component, and the PP/CaCO3 composites compatibilized by MAH-g-PP and the epoxy resin have higher crystallization peaks. This shows that an increase in the interaction adhesion between the CaCO3 and PP matrix, improving the nucleating activity of the filler and promoting crystallization of PP. Thermogravimetric analysis shows that the incorporation of the CaCO3 into the PP could improve the thermal stability of PP, and the addition of MAH-g-PP and the epoxy resin into the composites obviously could further improve the thermal stability. The mechanical properties of PP/MAH-g-PP/CaCO3 and PP/MAH-g-PP/CaCO3/epoxy composites are better than that of the PP/CaCO3 composites. The PP/MAH-g-PP/CaCO3/epoxy/EMI-2,4 composites have the best mechanical properties in all the PP/CaCO3 composites, which is attributed to the better interaction adhesion. The suitable content of epoxy resin is about 5 wt% in the presence of MAH-g-PP in the PP/CaCO3 composites, while an excess epoxy resin of above 5 wt% acts as an organic filler for PP.

Optimum Calcium Carbonate Filler Concentration for Flexible Polyurethane Foam Composite

The production cost of flexible polyurethane foam is significantly dependent on the cost of polyol, which constitute the largest percentage of materials used in foam production with the characteracterics to induce superior mechanical properties. Suitable fillers that are relatively cheap can be introduced in the foam matrix as replacement for polyol. However, certain compositions of filler have deleterious effect on some relevant mechanical properties of the foam. This paper investigates the effect of CaCO3 filler in flexible polyurethane foam matrix for the dual purposes of achieving sustained mechanical properties and reduction in production cost. The optimum CaCO3 composition was found to be 20 wt % representing a concomitant 18.54% reduction in cost of production.

Study on Properties and Preparation of Thermoplastic Polyurethane Hot-Melt Adhesive

The thermoplastic polyurethane elastomer (TPU) was firstly synthesized by using polybutylene adipate (PBA) as soft segments, methane-4-4’-diisocyanate(MDI) and 1,4–butanediol(BDO) as hard segments. The polyurethane hot-melt adhesive was then prepared by adding the tackifying resin, filler and other auxiliaries into the TPU matrix. The structure of the synthetic products was characterized by Infrared Spectrum and the thermal properties and microstructure of polyurethane hot-melt adhesive was tested by the thermogravimetric(TG) and the scanning electron microscopy(SEM), respectively. The results showed that the thermoplastic polyurethane elastomer had the expected structure, the shear strength of polyurethane hot-melt adhesive increased with the pentaerythritol abietate content increasing when the addition of the pentaerythritol abietate is less than 20 wt%, and decreased with the content of CaCO3 filler and petroleum resin increasing, respectively; the thermal stability was improved, and the char yields of the polyurethane blends increased with adding the filler CaCO3. When the molar ratio of PBA:MDI:BDO was 1:2:1, the addition of pentaerythritol abietate and filler CaCO3 was 20 wt% and 30 wt%, the comprehensive performance of PU hot-melt adhesive was better and the shear strength was 7.37 MPa.

Influence of calcium carbonate on RTM and RTM light processing and properties of molded composites

In the RTM light composite manufacturing process, inorganic fillers are commonly added to the resin to reduce cost and alter the final composite properties, especially rigidity, even though they also adversely affect processability. The aim of this study is to evaluate resin characteristics, reinforcement permeability, and mechanical properties of the composite and analyze the detrimental effects when a variable amount of calcium carbonate (CaCO3) is added to the resin. The addition of calcium carbonate increased the viscosity and gel time of the resin and considerably decreased the permeability of the reinforcement and therefore the expected process productivity. Besides, Barcol hardness, short-beam strength, and elastic modulus increased for higher CaCO3 content, whereas Izod impact, flexural, and tensile strengths decreased. Besides, the coarser CaCO3 filler particles managed to penetrate only partially into the fiber-rich layer of the combination mat used, which comprised of a PP flow media core and glass fibers at the surface.

Mechanical properties, thermal stability, and crystallization kinetics of poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate)/calcium carbonate composites

AbstractBacterial polyester poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) (P3/4HB) containing 5 mol% 4HB was composited with different calcium carbonate (CaCO3) fillers. The effect of CaCO3 contents on thermal properties, mechanical property, and crystallization kinetics was evaluated. The thermal stability of P3/4HB was reduced by mixing with CaCO3 particles. With increasing CaCO3 content, the elongation at break, tensile strength, and impact strength decrease; however, elastic modulus increases. When P3/4HB with 20 mol% 4HB was added into the P3/4HB/CaCO3 composite, the impact strength were enhanced significantly; however, the elongation at break and tensile strength were only slight to moderate improvements. However, when compared with nano‐ and light‐CaCO3, heavy CaCO3 had the best mechanical properties. The nonisothermal and isothermal crystallization results demonstrated that the crystallization rate of P3/4HB was reduced and the highest crystallinity was obtained for all kinds of CaCO3 fillers at 40 phr content. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers