Biodegradable thermoplastic elastomer comprising PLLCA and CaCO<Subscript>3</Subscript> whiskers: mechanical properties,thermal stability and shape memory properties

A biodegradable and thermoplastic elastomer—poly(L-lactide-co-ε-caprolactone) (PLLCA)—was reinforced with 5, 10, 20, and 30 wt% of CaCO₃ whiskers. We assessed the influence of the CaCO₃ whisker content on the mechanical and thermal properties of the PLLCA/CaCO₃ whisker composites. Scanning electron microscopy (SEM) revealed that the CaCO₃ whiskers were uniformly distributed in the composite matrices. The results of differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) showed that the glass transition temperatures (T _g) of the composites increased slightly with increasing CaCO₃ whisker content. At low CaCO₃ whisker contents, the tensile strengths of the composites increased sharply with increasing CaCO₃ content, the Young’s moduli also increased, and the elongation at break values gradually decreased. Thermogravimetric analysis (TGA) showed that the CaCO₃ whiskers can promote the thermal degradation of PLLCA. Shape memory test results indicated that an appropriate amount of CaCO₃ whiskers can improve the shape memory properties of PLLCA.     

Effect of Processing Method on Morphological and Rheological Properties of PC/CaCO3 Nanocomposites

The focus of this work is to investigate the effect of different manufacturing methods on nanoparticles dispersion and rheological properties of polycarbonate (PC) filled nano-calcium carbonate (CaCO₃) nanocomposites. Two methods were used to prepare the PC/CaCO₃ nanocomposites through twin-screw extruder: one was compounding PC with CaCO₃ nano-powder, named PC-CP; another was compounding PC with CaCO₃ aqueous suspension, named PC-CAS. The relationship between the processing method and the particle dispersion, matrix molecular weight and rheological properties of the nanocomposite was discussed. Morphological observation showed that nanoparticles were dispersed more homogeneously in PC-CAS. Gel permeation chromatography (GPC) test showed that molecular weight drop of PC-CAS was smaller than PC-CP when CaCO₃ content under 2.2 wt%. Melt flow rate (MFR) and capillary rheological behavior indicated the change of rheological property of PC-CP was larger than PC-CAS while CaCO₃ content under 2.6 wt%. In general, both the dispersion and rheological property of PC-CAS were better than PC-CP under a reasonable CaCO₃ content.     

Improvement of thermal and fire properties of polypropylene

In the present research, the thermal stability and fire properties of polypropylene (PP) have been improved through direct melt intercalation of PP, organically modified montmorillonite (OMMT), calcium carbonate (CaCO₃) nanoparticles, and conventional flame retardants, i.e., decabromodiphenyl oxide (DB) and antimony trioxide (AO). The morphology of the compound was characterized by means of X‐ray diffractometry and transmission electron microscopy. Thermogravimetry analysis (TGA), cone‐calorimetry, limiting oxygen index, UL‐94, and tensile tests were also employed to investigate thermal and mechanical properties as well as the flammability of the compounds. Data, obtained from TGA, indicated that simultaneous incorporation of both OMMT and CaCO₃ nanoparticles forms a synergistic effect to improve both the thermal and thermo‐oxidative stability. The kinetic analysis of polymer degradation showed that the presence of nanoparticles hindered the thermal degradation of PP. The combination of OMMT and CaCO₃ was more effective to improve fire properties than OMMT and DB/AO. The experimental results indicated that the incorporation of OMMT and CaCO₃ improved both the tensile (i.e., the increase of yield strength, tensile strength, and Young's modulus) and thermal properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of calcium carbonate whisker content on the morphology,crystallization, and mechanical properties of poly(para‐dioxanone)/Calcium carbonate whisker composites

In this work, poly(para‐dioxanone) (PPDO) was mixed with 0, 1, 5, 10, 20, and 30 weight percent (wt%) calcium carbonate (CaCO₃) whiskers by solution coprecipitation. Samples were compression molded into bars using a platen vulcanizing press. It has assessed the influence of the CaCO₃ whisker content on the morphology, thermal, mechanical, and crystalline properties of the PPDO/CaCO₃ whisker composites, using differential scanning calorimetry (DSC), polarized optical microscopy, scanning electron microscopy, and X‐ray diffraction. DSC showed that the glass transition temperature (T_g) and crystallization temperature (T_c) of the composites increased with increasing CaCO₃ whisker content. At low CaCO₃ whisker content (1 wt%), the degree of crystallinity (Dc) of PPDO increased sharply. The addition of higher content of CaCO₃ whisker would cause more agglomeration in PPDO matrix, so that the mechanical properties of PPDO/CaCO₃ whisker composites would gradually decrease. The mechanical properties of PPDO were changed by the presence of CaCO₃ whiskers; the optimal amount of CaCO₃ whisker was 1 wt%, which sharply improved the tensile strength of PPDO by 54%. POLYM. COMPOS., 37:3442–3448, 2016. © 2015 Society of Plastics Engineers     

Kinetics of thermal degradation of nanometer calcium carbonate/linear low‐density polyethylene nanocomposites

To improve the thermal properties of linear low‐density polyethylene (LLDPE), the CaCO₃/LLDPE nanocomposites were prepared from nanometer calcium carbonate (nano‐CaCO₃) and LLDPE by melt‐blending method. A series of testing methods such as thermogravimetry analysis (TGA), differential thermogravimetry analysis, Kim‐Park method, and Flynn‐Wall‐Ozawa method were used to characterize the thermal property of CaCO₃/LLDPE nanocomposites. The results showed that the CaCO₃/LLDPE nanocomposites have only one‐stage thermal degradation process. The initial thermal degradation temperature T₀ increasing with nano‐CaDO₃ content, and stability of LLDPE change better. The thermal degradation activation energy (E_a) is different for different nano‐CaCO₃ content. When the mass fraction of nano‐CaCO₃ in nanocomposites is up to 10 wt %, the nanocomposite has the highest thermal degradation E_a, which is higher (28 kJ/mol) than pure LLDPE. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

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     

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.     

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.     

Rheological and mechanical properties of PVC/CaCO3 nanocomposites prepared by in situ polymerization

Poly(vinyl chloride) (PVC)/calcium carbonate (CaCO₃) nanocomposites were synthesized by in situ polymerization of vinyl chloride (VC) in the presence of CaCO₃ nanoparticles. Their thermal, rheological and mechanical properties were evaluated by dynamic mechanical analysis (DMA), thermogravimetry analysis (TGA), capillary rheometry, tensile and impact fracture tests. The results showed that CaCO₃ nanoparticles were uniformly distributed in the PVC matrix during in situ polymerization of VC with 5.0 wt% or less nanoparticles. The glass transition and thermal decomposition temperatures of PVC phase in PVC/CaCO₃ nanocomposites are shifted toward higher temperatures by the restriction of CaCO₃ nanoparticles on the segmental and long-range chain mobility of the PVC phase. The nanocomposites showed shear thinning and power law behaviors. The ‘ball bearing’ effect of the spherical nanoparticles decreased the apparent viscosity of the PVC/CaCO₃ nanocomposite melts, and the viscosity sensitivity on shear rate of the PVC/CaCO₃ nanocomposite is higher than that of pristine PVC. Moreover, CaCO₃ nanoparticles stiffen and toughen PVC simultaneously, and optimal properties were achieved at 5 wt% of CaCO₃ nanoparticles in Young's modulus, tensile yield strength, elongation at break and Charpy notched impact energy. Detailed examinations of micro-failure micromechanisms of impact and tensile specimens showed that the CaCO₃ nanoparticles acted as stress raisers leading to debonding/voiding and deformation of the matrix material around the nanoparticles. These mechanisms also lead to impact toughening of the nanocomposites.     

Effect of particle size and surface modification on mechanical properties of poly(para‐dioxanone)/inorganic particles

Poly(para‐dioxanone) (PPDO)‐based composites have been prepared by blending PPDO with three different types of CaCO₃ particles, CC1 (nano‐CaCO₃), CC2 (CaCO₃ whisker), and CC3 (silane‐coated CaCO₃ whisker). The effects of particles size, interface adhesion, and crystallinity of composites on mechanical properties were discovered through analysis of the morphology of fracture surfaces, thermal characteristics, and crystalline structure. DSC revealed that the CaCO₃ particles acted as a nucleating agent and promoted crystallinity of PPDO. The effect of CaCO₃ particles on crystallization of PPDO was clearly revealed by using the nucleating efficiency. Smaller size particles exhibit greater nucleating efficiency. Adhesion between PPDO and the CaCO₃ particles plays major roles on the mechanical properties of composites. The tensile strength of PPDO was improved over 54%. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Effects of the reinforcement and toughening of acrylate resin/CaCO3 nanoparticles on rigid poly(vinyl chloride)

Novel composite particles based on nanoscale calcium carbonate (nano‐CaCO₃) as the core and polyacrylates as the shell were first synthesized by in situ encapsulating emulsion polymerization in the presence of the fresh slush pulp of calcium carbonate (CaCO₃) nanoparticles. Subsequently, these modified nanoparticles were compounded with rigid poly(vinyl chloride) (RPVC) to prepare RPVC/CaCO₃ nanocomposites. At the same time, the effects of the reinforcement and toughening of these modified nanoparticles on RPVC were investigated, and the synergistic effect of modified nanoparticles with chlorinated polyethylene (CPE) was also studied. The results showed that in the presence of nano‐CaCO₃ particles, the in situ emulsion polymerization of acrylates was carried out smoothly, and polyacrylates successfully encapsulated on the surface of nano‐CaCO₃ to prepare the modified nanoparticles, breaking down nano‐CaCO₃ particle agglomerates, improving their dispersion in the matrix, and also increasing the particle–matrix interfacial adhesion. Thus, the effects of the reinforcement and toughening of these modified nanoparticles on RPVC were very significant, and the cooperative effect of the nanoparticles with CPE occurred in the united modification system. Scanning electron microscopy analyses indicated that large‐fiber drawing and network morphologies coexisted in the system of joint modification of nanoparticles with CPE. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3940–3949, 2007     

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.     

Coincorporation of nano‐silica and nano‐calcium carbonate in polypropylene

In this study, various polypropylene (PP) nanocomposites were prepared by melt blending method. The effects of different spherical nanofillers, such as 50 nm CaCO₃ and 20 nm SiO₂, on the linear viscoelastic property, crystallization behavior, morphology and mechanical property of the resulting PP nanocomposites were examined. Rheological study indicated that coincorporation of nano‐SiO₂ and nano‐CaCO₃ favored the uniform dispersion of nanoparticles in the PP matrix. Differential scanning calorimeter (DSC) and polarizing optical microscopy (POM) studies revealed that the coincorporation of SiO₂ and CaCO₃ nanoparticles could effectively improve PP crystallizability, which gave rise to a lower supercooling temperature (ΔT), a shorter crystallization half‐life (t_1/2) and a smaller spherulite size in comparison with those nanocomposites incorporating only one type of CaCO₃ or SiO₂ nanoparticles. The mechanical analysis results also showed that addition of two types of nanoparticles into PP matrix gave rise to enhanced performance than the nanocomposites containing CaCO₃ or SiO₂ individually. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of polyacrylamide‐calcium carbonate and polyacrylamide‐calcium sulfate nanocomposites

Polyacrylamide‐calcium carbonate (PAM/CaCO₃) and polyacrylamide‐calcium sulfate (PAM/CaSO₄) nanocomposites were prepared via solution‐mixing technique. The resulting PAM‐based nanocomposites with various CaCO₃ and CaSO₄ nanoparticles contents (0–4% w/w) were investigated. Nanoparticles of CaCO₃ and CaSO₄ were synthesized by in situ deposition technique. In this technique, the surface modification of nanoparticles was performed by nonionic polymeric surfactant. The particle size of nanoparticles was recognized by X‐ray diffraction and scanning electron microscope (SEM) analysis which confirms that the particle has diameter of 25–33 nm. As prepared, nanocomposites films (thickness, 40‐μm) were characterized by Fourier transform infrared (FT‐IR), SEM, and energy‐dispersive X‐ray spectroscopy (EDS). FT‐IR shows the chemical structure of nanocomposites where as SEM analysis suggested that the nanofillers dispersed well in polymer matrix and EDS shows the elemental composition of the nanocomposite samples. Thermal properties of the nanocomposites were studied by using differential scanning calorimetric analysis. The PAM/CaCO₃ and PAM/CaSO₄ nanocomposites showed a higher glass transition temperature and a better thermal stability compared to the pure PAM. The glass transition temperature (T_g) of nanocomposites increases with increase in content of nanoparticles. It may be owing to the interaction between inorganic and organic components. POLYM. COMPOS.,, 2012. © 2012 Society of Plastics Engineers     

Effect of Dispersion Condition of Calcium Carbonate on the Crystallization and Melting Behavior of Polypropylene/CaCO3 Nanocomposites

Polypropylene/calcium carbonate (PP/CaCO₃) nanocomposites were prepared by melt compounding (C-1) and novel compounding process (C-2), respectively. Scanning electronic microscope (SEM) results illustrated that CaCO₃ nanoparticles were well dispersed at nanoscale in C-2, whereas the nanoparticles were mostly aggregate in C-1. Differential scanning calorimetry (DSC) measurements indicated the onset crystallization temperature was increased by 11.4°C and the supercooling wasdecreased by 13.68°C in C-2. A faster crystallization rate, a higher melting point, and a higher degree of crystallization in C-2 were also detected. Polarization light microscope (PLM) photographs showed the spherulites sizes of C-2 were 60 mm, whereas common spherulites with an average size of about 200 mm were observed in both pure PP and C-1. These phenomena demonstrated that the well-dispersed CaCO₃ nanoparticles could result in heterogeneous nucleation effect on PP even at quite low loading Q2 (1.5% wt.).     

Polypropylene/calcium carbonate nanocomposites

Polypropylene (PP) and calcium carbonate nanocomposites were prepared by melt mixing in a Haake mixer. The average primary particle size of the CaCO₃ nanoparticles was measured to be about 44 nm. The dispersion of the CaCO₃ nanoparticles in PP was good for filler content below 9.2 vol%. Differential scanning calorimetry (DSC) results indicated that the CaCO₃ nanoparticles are a very effective nucleating agent for PP. Tensile tests showed that the modulus of the nanocomposites increased by approximately 85%, while the ultimate stress and strain, as well as yield stress and strain were not much affected by the presence of CaCO₃ nanoparticles. The results of the tensile test can be explained by the presence of the two-counter balancing forces—the reinforcing effect of the CaCO₃ nanoparticles and the decrease in spherulite size of the PP. Izod impact tests suggested that the incorporation of CaCO₃ nanoparticles in PP has significantly increased its impact strength by approximately 300%. J-integral tests showed a dramatic 500% increase in the notched fracture toughness. Micrographs of scanning electron microscopy revealed the absence of spherulitic structure for the PP matrix. In addition, DSC results indicated the presence of a small amount of β phase PP after the addition of the calcium carbonate nanoparticles. We believe that the large number of CaCO₃ nanoparticles can act as stress concentration sites, which can promote cavitation at the particle-polymer boundaries during loading. The cavitation can release the plastic constraints and trigger mass plastic deformation of the matrix, leading to much improved fracture toughness.     

Viscoelastic,thermal, and morphological analysis of HDPE/EVA/CaCO<Subscript>3</Subscript> ternary blends

High density polyethylene (HDPE), calcium carbonate (CaCO₃), and ethylene vinyl acetate (EVA) ternary reinforced blends were prepared by melt blend technique using a twin screw extruder. The thermal properties of these prepared ternary blends were investigated by differential scanning calorimetry. The effect of EVA loading on the melting temperature (T _m) and the crystallization temperature (T _C) was evaluated. It was found that the expected heterogeneous nucleating effect of CaCO₃ was hindered due to the presence of EVA. The melt viscosities of the ternary reinforced blends were affected by the % loading of CaCO₃, EVA, and vinyl acetate content. Viscoelastic analysis showed that there is a reduction of the storage modulus (G′) with increasing of EVA loading as compared to neat HDPE resin or to HDPE/CACO₃ blends only. The morphology of the composites was characterized by scanning electron microscopy (SEM). The dispersion and interfacial interaction between CaCO₃ with EVA and HDPE matrix were also investigated by SEM. We observed two main types of phase structures; encapsulation of the CaCO₃ by EVA and separate dispersion of the phases. Other properties of ternary HDPE/CaCO₃/EVA reinforced blends were investigated as well using thermal, rheological, and viscoelastic techniques.     

Effects of nanoparticle treatment on the crystallization behavior and mechanical properties of polypropylene/calcium carbonate nanocomposites

Effects of nanoparticle surface treatment on the crystallization behavior and mechanical properties of polypropylene (PP)/CaCO₃ nanocomposites were investigated by using differential scanning calorimetry (DSC), polarized optical microscope (POM), X‐ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results demonstrated that the interfacial interaction formed between PP and nanoparticles significantly influenced the thermal and mechanical properties of nanocomposites. It was found that CaCO₃ nanoparticles modified by a single aluminate coupling agent (CA‐1) could improve the onset crystallization temperature more effectively than that modified by a compound surface‐treating agent (CA‐2) could. However, there is no significant difference in total rate of crystallization for the two PP/CaCO₃ nanocomposites (PPC‐1 and PPC‐2), which contained CA‐1 and CA‐2, respectively. In contrast, CA‐2 modified nanoparticles could cause smaller spherulites and induce much more β‐phase crystal in nanocomposites than that of CA‐1 modified nanoparticles. This may be explained by a synergistic effect of aluminate coupling agent and stearic acid in CA‐2, which also resulted in an improved toughness for PPC‐2. © 2006 Wiley Periodicals, Inc. J Appl PolymSci 102: 3480–3488, 2006     

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     

Preparation and properties of nanocomposite of poly(phenylene sulfide)/calcium carbonate

Summary A way to prepare Poly (phenylene sulfide) (PPS) nanocomposite was introduced in the paper. The nanocomposite of PPS/CaCO₃ can be prepared by melt mixing process. The dispersion of the CaCO₃ nanoparticles in PPS was good when filler content below 5 wt %. Differential scanning calorimeter (DSC) and small-angle light scattering (SALS) results indicated that the CaCO₃ nanoparticles could induce the nucleation but retard the mobility of polymer chains. The results of mechanical tests showed that a small amount of nanoparticles has resulted in a slight improvement in the tensile strength and a significantly 300% increase in the fracture toughness. We believe that the CaCO₃ nanoparticles can act as stress concentration sites, which can promote cavitation at the particles boundaries during loading. The cavitation can trigger mass plastic deformation of the matrix, leading to much improve fracture toughness.