Synthesis of CaCO3–P(MMA–BA) nanocomposite and its application in water based alkyd emulsion coating

As part of broader effort to synthesize a new class of water-based composite, hybrid emulsion polymerization was carried out with acrylic monomers [methyl methacrylate (MMA), n-butyl acrylate (BA)]. Nanocomposite of P(MMA–BA)/nano CaCO₃ was synthesized by in situ emulsion polymerization. Water-based alkyd coating with various proportions nano CaCO₃, P(MMA–BA) and its nanocomposite was formulated. Extent of polymerization with and without nano CaCO₃ was measured using gravimetric method. Thermal properties of neat polymer, nanocomposite and coating films were evaluated by TGA and DSC, DTA analysis. Uniform dispersion of nano CaCO₃ in polymer matrix was ensured from SEM/TEM images. Incorporation of nanoparticles to hybrid polymer and nanocomposite to alkyd emulsion showed significant enhancement in mechanical and thermal properties. Dual role of nanocomposite in coating; as a partial binder and a filler to improve property profile of neat coating has been reported.     

Synthesis of CaCO3–P(MMA–BA) nanocomposite and its application in water based alkyd emulsion coating

As part of broader effort to synthesize a new class of water-based composite, hybrid emulsion polymerization was carried out with acrylic monomers [methyl methacrylate (MMA), n-butyl acrylate (BA)]. Nanocomposite of P(MMA–BA)/nano CaCO₃ was synthesized by in situ emulsion polymerization. Water-based alkyd coating with various proportions nano CaCO₃, P(MMA–BA) and its nanocomposite was formulated. Extent of polymerization with and without nano CaCO₃ was measured using gravimetric method. Thermal properties of neat polymer, nanocomposite and coating films were evaluated by TGA and DSC, DTA analysis. Uniform dispersion of nano CaCO₃ in polymer matrix was ensured from SEM/TEM images. Incorporation of nanoparticles to hybrid polymer and nanocomposite to alkyd emulsion showed significant enhancement in mechanical and thermal properties. Dual role of nanocomposite in coating; as a partial binder and a filler to improve property profile of neat coating has been reported.     

Poly(vinyl alcohol)/CaCO3‐diacid nanocomposite: Investigation of physical and wetting properties and application in heavy metal adsorption

Poly(vinyl alcohol) (PVA) nanocomposite and modified CaCO₃ nanoparticles (NPs) were fabricated by ultrasound agitation method with particle content altering from 3, 5, and 8 wt %. The CaCO₃ surface was successfully treated by 10 wt % of bioactive dicarboxylic acid (DA). The influences of loading modified NPs on the thermal, mechanical, adsorption, contact angle, and physical properties of the poly(vinyl alcohol) nanocomposite films were thoroughly studied. The results showed that incorporation of modified CaCO₃ into the PVA matrix had better performance than the pure PVA. Meanwhile, tensile strength, Young's modulus, and thermal stability are enhanced from 33.36 MPa, 1.26 GPs, and 242.918C (neat PVA) to 81.7 MPa, 4.81 GPa, and 312.95 °C (PVA/CaCO₃‐DA NC 5 wt %), respectively. Also, the adsorption capacity of the PVA/CaCO₃‐DA NCs 5 and 8 wt % revealed that the NC films could act as an appropriate absorbent for the removal of Cd(II) ions with maximum adsorption capacity of about 20.70 and 25.19 mg g^?1 for Cd(II), respectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45414.     

Water-Based PMMA-Nano-CaCO3 Nanocomposites by In Situ Polymerization Technique: Synthesis,Characterization and Mechanical Properties

Water-based nanocomposite was synthesized using in-situ polymerization of Methyl Methacrylate. Nano-CaCO₃ was added during polymerization along with aqueous solution of surfactant. Quantity of nano-CaCO₃ was varied as 0, 2 and 4% of monomer quantity. XRD gram shows the presence of nano-CaCO₃, which causes the crystalline nature to nanocomposites. TEM images of nano-CaCO₃ show cubic structure. Synthesis of nanocomposite follows pseudo–first-order kinetics polymerization. PMMA-4% CaCO₃ nanocomposite showed significant improvement in UV absorbance and in mechanical properties like adhesion, scratch resistance as compared to neat PMMA and 2% CaCO₃ nanocomposite.     

New approach for simultaneous enhancement of anticorrosive and mechanical properties of coatings: Application of water repellent nano CaCO3–PANI emulsion nanocomposite in alkyd resin

New alkyd coatings were prepared by addition of water-based polyaniline–4% CaCO₃ (PAC) nanocomposites into alkyd resin. Pure polyaniline (PANI) and PAC were synthesized using ultrasound assisted emulsion polymerization and added to alkyd resin to form nanocomposite coating. Nano CaCO₃ was added in different percentage ranging from 0% to 8% of monomer during the synthesis of polyaniline. XRD and TEM reveals that water repellent nano CaCO₃ is thoroughly dispersed in PANI matrix. The effect of PANI and PAC nanocomposite on mechanical and anticorrosion performance of alkyd coating was evaluated. An electrochemical measurement (Tafel Plots) shows that corrosion current I_corr was decreased from 0.89 to 0.03 μA/cm², when PAC nanocomposite was added to neat coatings. Positive shift of E_corr. also indicates that PAC nanocomposite acts as an anticorrosive additive to alkyd coating. Presence of water repellant nano CaCO₃ in PAC nanocomposite has exhibited dual effect, such as improvement in mechanical and anticorrosion properties. The experimental results have shown superiority of PAC nanocomposite over PANI when PAC nanocomposite added to alkyd coatings.     

Functionalized graphene nanoplatelets as a barrier enhancing filler in organic photovoltaic encapsulant

This research work has concerned the development of polymer films, reinforced with graphene nanoplatelets (GNP) for use as encapsulating films for organic photovoltaic (OPV) cells. The aim of this work was to investigate the effects of concentrations and orientations of GNP on mechanical, optical, and barrier properties of polymer composite films. In this regard, the neat GNP was modified with Fe₃O₄ prior to mixing with acrylate-based monomers. The mixture was then cured by photo-polymerization with and without the application of magnetic fields. Changes in orientation of the functionalized GNP with the direction of applied magnetic fields were analyzed by optical microscopy, scanning electron microscopy, and transmission electron microscopy. From the results, it was found that by inducing the orientation of functionalized GNP to the horizontal direction (with respect to the OPV cell), the great enhancement in tensile and barrier properties of the polymer composite films was achieved. This led to the longer performance of the OPV cell encapsulated with the nanocomposite film with 0.1 phr of the horizontally oriented GNP in comparison with the OPV cell encapsulated with the film reinforced with randomly oriented GNP at the same content.     

Preparation and characterization of poly(ε‐caprolactone)/calcium carbonate nanocomposites and nanocomposite foams

Biodegradable poly(ε‐caprolactone) (PCL)/calcium carbonate (CaCO₃) nanocomposites were prepared and characterized. Effect of CaCO₃ on thermal and mechanical properties of PCL matrix was studied. Results showed that CaCO₃ acts as a crystallization nucleating agent and introduction of CaCO₃ leads to improved mechanical properties of the PCL matrix. PCL/CaCO₃ nanocomposite foams were prepared using chemical foaming method. Cellular parameters such as mean cell size, cell wall thickness, and cell density were collected. The cellular structure of nanocomposite foams changes with different CaCO₃ loading. Mean cell size achieved the minimum value at 5 wt% CaCO₃ loading, and cell wall thickness increased with CaCO₃ content. The changes in cellular structure and improvement of mechanical properties also enhanced the mechanical properties of PCL/CaCO₃ nanocomposite foams. Compressive moduli of PCL/CaCO₃ nanocomposite foams with similar density increased with increasing CaCO₃ loading. POLYM. COMPOS., 31:1653–1661, 2010. © 2009 Society of Plastics Engineers     

Development of isotactic polypropylene and stearic acid-modified calcium carbonate composite: a promising material for microwavable packaging

Isotactic polypropylene (PP) composite films were developed, with incorporation of CaCO₃ particles as active filler. Stearic acid was used for the surface treatment of CaCO₃ to provide composite films having improved mechanical, thermal and barrier properties against oxygen as well as water vapor, in comparison to neat PP films. The filler was melt mixed with PP in a twin-screw extruder, and the films produced through melt blowing. A slight reduction in T _g values of the filled PP films was observed, along with an increase in the overall crystallization extent relative to neat PP films. X-ray diffraction data confirmed that the CaCO₃ particles served as a β-nucleating agent capable of promoting the formation of the β-crystalline phase of PP and reducing the spherulite size, with stearic acid-coated CaCO₃ being most effective in promoting these features. Exposing the films to microwave radiation altered their properties; at low irradiation power, the T _g values and the degree of β-crystallization were enhanced, and barrier properties against oxygen and water vapor showed improvements. In contrast, no significant changes in the appearance of the film surface were evident highlighting the potential of these PP-based composite films in microwave packaging applications.     

Advance polymeric carbon nanocomposite films with enhanced thermo‐mechanical properties

The homogenous nanocomposite films of UV/O₃ oxidized multiwall carbon nanotubes (MWCNTs) subsequently modified with aniline moiety were synthesized with polymethylmethacrylate (PMMA) through free radical polymerization. The phenylamine functional groups present on the surface of MWCNTs providing an anchoring sites for deposition of Ag metal nanoparticles (NP).The in situ free radical polymerization of MMA in the presence of these well dispersed nanotubes gave a new class of radiation resistant nanocomposite films. The synthesized materials were characterized by FT‐IR, TGA, TEM, EDX, TC, DMA, universal testing machine, and optical microscopy to ascertain their structural morphologies, thermal stability, and mechanical strength. The microscopic and structural properties reflect the homogenous mixing of modified MWCNTs in polymer matrix contributing in enhancement of thermal stability, thermo‐mechanical strength, glass transition temperatures, and thermal conductivity of nanocomposites even at 0.25 wt% addition of modified nanofiller. Thermal and thermo‐mechanical behavior of pre‐ and post‐UV/O₃ irradiated nanocomposite films have been compared with neat polymer. The results revealed that modified nanofiller network can effectively disperse the radiation and has a dramatic reinforcement effect on the nature of degradation of PMMA matrix. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Improved properties of poly(butylene adipate-co-terephthalate)/calcium carbonate films through silane modification

One of the most used inorganic fillers is calcium carbonate which quite efficiently enhances the mechanical characteristics while simultaneously lower the cost of thermoplastics, particularly for biodegradable polyester. Virtually, all studies so far have focused on the quest for the filling and modification of nano-sized calcium carbonates. However, the quantity of nano-sized CaCO₃ added in the polymer is usually lower than 10%, owing to its high-surface energy and high-surface area and makes powder easier to agglomerate. In this work, we prepared poly(butylene adipate-co-terephthalate) (PBAT)/calcium carbonate composite films by extrusion-blown films with up to 40 wt% micro-sized CaCO₃ content. The influence of particle size (5–12 μm) and modification of the particles (with and without silane coupling agents) on the rheological and mechanical properties was thoroughly investigated. Of all the particle sizes employed in this study, the 5 μm (3000 mesh) particles with 30 wt% content coated with 2 wt% aliphatic silane coupling (CA1) agent was observed to furnish the optimum combination of characteristics. The mechanical properties of P7C3/CA1-2 film even better than that of neat PBAT film. These results provided a simple approach for PBAT/CaCO₃ films manufacture with low-cost and simultaneously with sound mechanical properties, which can be good candidate for mulching films and packaging applications.     

Nanotailoring of polyurethane adhesive by polyhedral oligomeric silsesquioxane (POSS)

The development and commercialization of nanoparticles such as nanoclays (NCs), carbon nanotubes (CNTs) and polyhedral oligomeric silsesquioxanes (POSS) offers new possibilities to tailor adhesives at the nanoscale. Four types of POSS, with reactive mono-functional groups of isocyanatopropyl, glycidoxypropyl, aminoethyl and non-reactive octaphenyl, were incorporated in concentrations of 1, 3 and 5 wt% into a polyurethane (PU)-based adhesive. Thermo-mechanical bulk properties were studied using dynamic mechanical analysis (DMA). Adhesive properties were characterized in shear and peel modes. Atomic force microscopy (AFM) was used to study the nanoscale morphology. DMA measurements indicated that the neat PU possessed a glass transition temperature (T _g) of ≈ 30°C. The T _g of PU/POSS-glycidoxypropyl nanocomposite adhesive increased gradually with POSS concentration to 50°C for 5 wt%. PU/POSS-octaphenyl nanocomposite adhesive exhibited an increased T _g by 10°C for 5 wt%. The incorporation of POSS-isocyanatopropyl in the PU had no effect on the T _g. With respect to shear properties of POSS-octaphenyl-, POSS-isocyanatopropyl- and POSS-glycidoxypropyl-based PU nanocomposite adhesives, shear strength improved by 230, 178 and 137%, respectively, compared to neat PU. POSS-aminoethyl exhibited lower shear and peel strengths, while POSS-isocyanatopropyl provided the best balance of both higher shear and peel strengths compared to neat PU. It was concluded that the grafted functional group on the POSS and its reactivity with the PU network components were the decisive factors with respect to the thermo-mechanical, morphological and adhesive properties of the resulting nanocomposite adhesives. Consequently, the POSS/polyurethane based nanocomposite adhesives could be tailored for a large range of applications.     

Mechanical and thermal properties of bio‐based CaCO3/soybean‐based hybrid unsaturated polyester nanocomposites

Bio‐based calcium carbonate nanoparticles (CaCO₃) were synthesized via size reduction of eggshell powder using mechanical attrition followed by high intensity ultrasonic irradiation. The transmission electron microscopic (TEM) and BET surface area measurements show that these particles are less than 10 nm in size and a surface area of ～44 m²/g. Bio‐based nanocomposites were fabricated by infusion of different weight fractions of as‐prepared CaCO₃ nanoparticles into Polylite® 31325‐00 resin system using a non‐contact Thinky® mixing method. As‐prepared bio‐nanocomposites were characterized for their thermal and mechanical properties. TEM studies showed that the particles were well dispersed over the entire volume of the matrix. Thermal analyses indicated that the bio‐nanocomposites are thermally more stable than the corresponding neat systems. Nanocomposite with 2% by weight loading of bio‐CaCO₃ nanoparticles exhibited an 18°C increase in the glass transition temperature over the neat Polylite 31325 system. Mechanical tests have been carried out for both bio‐nanocomposites and neat resin systems. The compression test results of the 2% Bio‐CaCO₃/Polylite 31325 nanocomposite showed an improvement of 14% and 27% in compressive strength and modulus respectively compared with the neat system. Details of the fabrication procedure and thermal and mechanical characterizations are presented in this article. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1442–1452, 2013     

High density polyethylene/micro calcium carbonate composites: A study of the morphological,thermal, and viscoelastic properties

High density polyethylene (HDPE) with micro calcium carbonate (CaCO₃) masterbatch was pelletized by using a twin screw extruder and different ASTM specimens were molded by an injection molding machine. The morphology of the composites was characterized by scanning electron microscopy (SEM) and Image Analysis software. The dispersion and interfacial interaction between CaCO₃ and the polymer matrix were also investigated by SEM. The thermal properties of HDPE and its composites were investigated by differential scanning calorimetry (DSC). The crystallization process of the composites samples was found to be slightly different than that of the neat HDPE. Otherwise, the presence of CaCO₃ did not have a considerable effect on the melting behavior of the composites. Thermogravimetric analysis (TGA) revealed that the composites had better thermal stability than the neat HDPE resin as indicated by a higher temperature of 50% weight loss (T_50%) for the composites as compared to that of the neat resin. The viscoelastic properties of the composites and HDPE were also investigated via torsional and rotational techniques. The presence of CaCO₃ increased the shear modulus at low frequency of the composites at 80°C over that of the neat resin. However, at higher frequencies, the difference between the neat resin and the composites' shear modulus was less than that at low frequencies. The complex viscosity of the composite increased upon the addition of CaCO₃. However, the shear sensitivities of the neat resin and the microcomposite were similar. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Mechanical properties of blocked polyurethane/epoxy interpenetrating polymer networks

The mechanical properties of blocked polyurethane(PU)/epoxy interpenetrating polymer networks (IPNs) were studied by means of their static and damping properties. The studies of static mechanical properties of IPNs are based on tensile properties, flexural properties, hardness, and impact method. Results show that the tensile strength, flexural strength, tensile modulus, flexural modulus, and hardness of IPNs decreased with increase in blocked PU content. The impact strength of IPNs increased with increase in blocked PU content. It shows that the tensile strength, flexural strength, tensile modulus, and flexural modulus of IPNs increased with filler (CaCO₃) content to a maximum value at 5, 10, 20, and 25 phr, respectively, and then decreased. The higher the filler content, the greater the hardness of IPNs and the lower the notched Izod impact strength of IPNs. The glass transition temperatures (T_g) of IPNs were shifted inwardly compared with those of blocked PU and epoxy, which indicated that the blocked PU/epoxy IPNs showed excellent compatibility. Meanwhile, the T_g was shifted to a higher temperature with increasing filler (CaCO₃) content. The dynamic storage modulus (E′) of IPNs increased with increase in epoxy and filler content. The higher the blocked PU content, the greater the swelling ratio of IPNs and the lower the density of IPNs. The higher the filler (CaCO₃) content, the greater the density of IPNs, and the lower the swelling ratio of IPNs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1826–1832, 2006     

Preparation and properties of single-walled carbon nanotubes/poly(butylene terephthalate) nanocomposites

A neat poly(butylene terephthalate) (PBT) polymer and functionalized single-walled carbon nanotubes (F-SWNTs)/PBT nanocomposite films were prepared by solution casting technique. The SWNTs were functionalized by acid treatment, which introduced carboxylic groups onto the SWNTs. The morphological studies showed that the F-SWNTs were embedded and dispersed well within the PBT polymer matrix. The POM study illustrated that a neat PBT showed Maltese-type spherulites. It was also observed that the size of neat PBT spherulites was larger than F-SWNTs/PBT nanocomposite spherulites, which might be due to the nucleation effect of F-SWNTs in the case of nanocomposites. The thermal stabilities and mechanical properties such as stress yield and moduli of F-SWNTs/PBT nanocomposites were enhanced as compared to neat PBT. The DSC study showed that the melting temperature (T _m) of PBT was slightly increased by addition of F-SWNTs. This increase in T _m might be due to the formation of compact structure, which was formed through different types of molecular interactions with addition of F-SWNTs. It was also found that initially the solvent (distilled water, kerosene, 2 M HNO₃ solution) uptake by neat PBT polymer and its nanocomposites increased gradually, which became steady after specific intervals for each sample. The results also exhibited that the solvent uptake of F-SWNTs/PBT nanocomposites was less than neat PBT.     

Film‐forming behavior and mechanical properties of colloidal silica/polymer latex blends with high silica load

In this article, silica sol (diameter: 8–100 nm) and polymer latex (T_g < 25°C) were mixed and dried at room temperature to prepare nanocomposite films with high silica load (≥50 wt %). Effects of silica size, silica load, and the T_g of the polymer on the film‐forming behavior of the silica/polymer latex blend were investigated. The transparency, morphology, and mechanical properties of the nanocomposite films were examined by UV–Vis spectroscopy, SEM, and nanoindentation tests, respectively. Transparent and crack‐free films were produced with silica loads as high as 70 wt %. Thirty nanometers was found to be the critical silica size for the evolution of film‐forming behavior, surface morphology, and mechanical properties. Colloidal silica particles smaller than this critical size act as binders to form strong silica skeleton. This gives the final silica/polymer nanocomposite film its porous surface and high mechanical strength. However, silica particles with sizes of 30 nm or larger tend to work as nanofillers rather than binders, causing poor mechanical strength. We also determined the critical silica load appeared for the mechanical strength of silica/polymer film at high silica load. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Shear and extensional rheometry of PA6 reinforced with polyacrylic nanoparticles

Shear and extensional rheometry was carried out on polyamide 6 (PA6) reinforced with crosslinked polyacrylic nanoparticles (PNPs) with mean size of 8 nm. The PNPs were dispersed into a commercial, injection grade, PA6 matrix by melt extrusion, at a concentration of 3 wt%. Thermal analysis showed that the PNPs did not influence the melting and decomposition temperature of the polymer matrix. However, grafting of maleic anhydride to the PNPs (denoted PNP-g-MA) increased the decomposition temperature. On the other hand, X-ray scattering and small-angle light scattering showed that the degree of crystallinity and crystal size were reduced, relative to the neat PA6, i.e., the PNPs disrupted the ordering of the polymer chains. The shear rheological properties showed that the PA6/PNP nanocomposites exhibited a linear viscoelastic behavior. Small-strain oscillatory shear showed that PA6 exhibited a predominantly viscous behavior. However, addition of PNPs induced a predominantly elastic behavior, as measured by the mechanical damping tan δ (=G″/G′), and increased the zero-shear viscosity. The increase in melt elasticity and viscosity was greater for the PA6/PNP-g-MA nanocomposite. Extensional rheometry experiments demonstrated that when PNPs were added to PA6, they induced smaller extensional viscosity, η _ext, values in the matrix, at low strain rates. However, at higher strain rates the PNPs induced a strain hardening behavior. Whereas the neat polymer melt rapidly broke under extensional flow, the PA6/PNP nanocomposites first exhibited lower η _ext than the neat PA6, and then η _ext rapidly increased before breaking, i.e. a strain hardening behavior. The higher melt elasticity of the molten PA6 nanocomposites appears to arise from a jamming effect promoted by the PNPs.     

Structure and magnetic properties of regenerated cellulose/Fe3O4 nanocomposite films

Cellulose nanocomposites containing high contents of Fe₃O₄ nanoparticles were successfully prepared with regenerated cellulose films as a matrix and mixture solutions of Fe²⁺/Fe³⁺ as precursors. The structure and properties of the magnetic nanocomposite films were investigated with X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and vibrating sample magnetometry. Fe₃O₄ nanoparticles as prepared were irregular spheres and were homogeneously dispersed in the cellulose matrix. With an increase in the concentration of precursors from 0.2 to 1.0 mol/L, the content of Fe₃O₄ nanoparticles in the dried nanocomposites increased from 12 to 39 wt %, and the particle diameter increased from 32 to 64 nm. The cellulose nanocomposite films demonstrated superparamagnetic behavior, and their saturation magnetizations were in the range 4.2–21.2 emu/g, which were related to the increase in Fe₃O₄ nanoparticle content. With increasing nanophase content, the nanocomposite films displayed significantly anisotropic magnetic properties in the parallel and perpendicular directions. This study provided a green and facile method for the preparation of biobased nanocomposite films with high nanophase content and excellent magnetic properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Properties and structures of polylactide filled with poly(ε-caprolactone)-coated calcium carbonate

The poly(ε-caprolactone) (PCL)-coated microsized calcium carbonate (CaCO₃) was prepared by high-speed hybrid mechanical coating. Polylactide (PLA) was melt-blended with neat and modified CaCO₃ particles. Phase morphology, microstructure, and thermal dynamic rheological and mechanical properties of the composites were investigated. Differential scanning calorimetry reveals that the addition of coated CaCO₃ remarkably makes the cold crystallization temperature decrease but has little influence on the final degree of crystallinity of PLA. Dynamic rheological tests indicate that complex viscosity and loss modulus of modified CaCO₃ system are lower than those of neat CaCO₃ system. Scanning electron microscopic results show that the coated CaCO₃ microparticles disperse more uniformly in the PLA matrix compared with neat particles. The smooth and round coated particles promote the dispersion of CaCO₃ particles in the PLA matrix, and PCL enhances the interfacial adhesion between CaCO₃ particles and the PLA matrix. From mechanical tests, it is found that toughness of the composites is greatly improved by the incorporation of PCL-coated CaCO₃ microparticles. It is glad to see that the elongation at break of the composite with 15 phr coated CaCO₃ is as high as 310%. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Atomic Force Microscopy, thermal, viscoelastic and mechanical properties of HDPE/CaCO3 nanocomposites

High Density Polyethylene (HDPE) and calcium carbonate (CaCO₃) nanocomposites were prepared from masterbatch by melt blending in twin screw extruder (TSE). The physical properties of HDPE/CaCO₃ nanocomposites samples (0, 10 and 20?wt% CaCO₃ masterbatch) were investigated. The morphology, thermal, rheological/viscoelastic and mechanical properties of the nanocomposites were characterized by Atomic Force microscopy (AFM), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analyzer (DMA) as well as tensile test. The AFM images showed homogeneous dispersion and distribution of nano-CaCO₃ in the HDPE matrix. The DSC analysis showed a decrease in crystallinity of HDPE/CaCO₃ nanocomposites with the increase of CaCO₃ loading. This was due to the presence of nanofiller which could restrict the movement of the polymer chain segments and reduced the free volume/spaces available to be occupied by the macromolecules, thus, hindered the crystal growth. However, there was an increase in crystallization temperature about 1?C2?°C with the addition of CaCO₃. It was suggested that the CaCO₃ nanoparticles acted as nucleating agent. In melt rheology study, the complex viscosities of HDPE/CaCO₃ nanocomposites were higher than the HDPE matrix and increased with the increasing of CaCO₃ masterbatch loading. The DMA results showed that the storage modulus increased with the increasing of nano-CaCO₃ contents. The improvement was more than 40?%, as compared to that of neat HDPE. Additionally, the tensile test results showed that with the addition of CaCO₃ masterbatch, modulus elasticity of nanocomposites sample increased while yield stress decreased.