Nanocomposites of poly(vinyl chloride) and nanometric calcium carbonate particles: Effects of chlorinated polyethylene on mechanical properties,morphology, and rheology

Nanocomposites of poly(vinyl chloride) (PVC) and nano‐calcium carbonate (CaCO₃) particles were prepared via melt blending, and chlorinated polyethylene (CPE) as an interfacial modifier was also introduced into the nanocomposites through preparing CPE/nano‐CaCO₃ master batch. The mechanical properties, morphology, and rheology were studied. A moderate toughening effect was observed for PVC/nano‐CaCO₃ binary nanocomposites. The elongation at break and Young's modulus also increased with increasing the nano‐CaCO₃ concentration. Transmission electron microscopy (TEM) study demonstrated that the nano‐CaCO₃ particles were dispersed in a PVC matrix uniformly, and a few nanoparticles agglomeration was found. The toughening effect of the nano‐CaCO₃ particles on PVC could be attributed to the cavitation of the matrix, which consumed tremendous fracture energy. The notched Izod impact strength achieved a significant improvement by incorporating CPE into the nanocomposites, and obtained the high value of 745 J/m. Morphology investigation indicated that the nano‐CaCO₃ particles in the PVC matrix was encapsulated with a CPE layer through preparing the CPE/nano‐CaCO₃ master batch. The evaluation of rheological properties revealed that the introduction of nano‐CaCO₃ particles into PVC resulted in a remarkable increase in the melt viscosity. However, the viscosity decreased with addition of CPE, especially at high shear rates; thus, the processability of the ternary nanocomposites was improved. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2714–2723, 2004     

Toughening and reinforcement of rigid PVC with silicone rubber/nano‐CACO3 shell‐core structured fillers

To improve the mechanical properties and structure of poly(vinyl chloride) (PVC)/nano‐CaCO₃ nano composite, a core (nano‐CaCO₃)/shell (SR) structured filler (40–60 nm) was successfully prepared by refluxing methyl vinyl silicone rubber (SR) and nano‐CaCO₃ particles (coupling agent KH550, KH560, or NDZ‐101 as interfacial modifier) in toluene with vigorous stirring, according to an encapsulation model. It is effective in rigid PVC composite's toughness and reinforcement. The interfacial modifier's structure and interaction of nanocomposites of PVC/SR/nano‐CaCO₃ were studied. The results indicate that KH560 has the optimal interfacial modificatory effect. The environmental scanning electron microscope (ESEM) study testified that PVC/SR/nano‐CaCO₃ nanocomposites had a typical rubber–plastics‐toughening mechanism. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2560–2567, 2006     

Interfacial structures and mechanical properties of PVC composites reinforced by CaCO3 with different particle sizes and surface treatments

The effects of particle size and surface treatment of CaCO₃ particles on the microstructure and mechanical properties of poly(vinyl chloride) (PVC) composites filled with CaCO₃ particles via a melt blending method were studied by SEM, an AG‐2000 universal material testing machine and an XJU‐2.75 Izod impact strength machine. The tensile and impact strengths of CaCO₃/PVC greatly increased with decreasing CaCO₃ particle size, which was attributed to increased interfacial contact area and enhanced interfacial adhesion between CaCO₃ particles and PVC matrix. Titanate‐treated nano‐CaCO₃/PVC composites had superior tensile and impact strengths to untreated or sodium‐stearate‐treated CaCO₃/PVC composites. The impact strength of titanate‐treated nano‐CaCO₃/PVC composites was 26.3 ± 1.1 kJ m⁻², more than three times that of pure PVC materials. The interfacial adhesion between CaCO₃ particles and PVC matrix was characterized by the interfacial interaction parameter B and the debonding angle θ, both of which were calculated from the tensile strength of CaCO₃/PVC composites. Copyright © 2005 Society of Chemical Industry     

Production of nano‐calcium carbonate from shells of the freshwater channeled applesnail,Pomacea canaliculata,by hydrothermal treatment and its application with polyvinyl chloride

The use of naturally renewable shells of the freshwater channeled applesnail, Pomacea canaliculata, as a filler to replace commercial calcium carbonate (CaCO₃) was investigated in this study. Ground P. canaliculata shell particles were converted to nano‐CaCO₃ particles by the displacement reaction of calcium chloride in sodium carbonate solution followed by hydrothermal treatment at 100°C for 1 h to synthesize nano‐CaCO₃ with particle sizes of 30–100 nm in diameter. The mechanical properties, in terms of the tensile strength, elongation at brake and impact strength, of polyvinyl chloride (PVC) were greatly improved by mixing with nano‐CaCO₃ at 5–10 parts per hundred of resin. Additionally, the presence of nano‐CaCO₃ at the same levels increased the flame resistance and thermal stability of the PVC composite materials. POLYM. COMPOS., 36:1620–1628, 2015. © 2014 Society of Plastics Engineers     

Processability,morphology, thermal,and mechanical properties of rigid PVC composites with liquid macromolecular modifier‐coated CaCO3

Rigid poly(vinyl chloride) (PVC)/CaCO₃ and PVC/liquid macromolecular modifier (LMM) coated CaCO₃ (PVC/LCC) composites were both fabricated by melt mixing. The processability, micro‐structure, dynamic mechanical behavior and mechanical properties of PVC/CaCO₃ and PVC/LCC composites were studied by using torque rheometer, scanning electron microscope (SEM), dynamic mechanical analysis (DMA), and universal mechanical testing machine. The results showed that the synergistic effect of LMM and CaCO₃ particles accelerated the plasticization of PVC resins. The processability of PVC/LCC composites was improved. The dispersion of LCC in PVC matrix was improved by the modification of CaCO₃ particles with LMM. The T_gs of PVC/LCC composites were enhanced by filling with LCC. Because of the synergistic toughening of LMM and CaCO₃ particles, the PVC/LCC composites exhibited excellent notched impact properties at the optimum value of LCC particles content. POLYM. COMPOS., 36:1286–1292, 2015. © 2014 Society of Plastics Engineers     

Investigation of the addition of nano‐CaCo3 at dry mixing or onset of fusion on the dispersion,torque, and mechanical properties of compounded PVC

A Brabender torque rheometer equipped with an internal mixer was used to study the influence of compounding method on the properties of (rigid PVC)/(treated and untreated nano‐CaCO₃) nanocomposites. Two different methods were studied for the addition of surface treated and untreated nano‐CaCO₃ during the melt mixing of rigid PVC. Direct dry mixing of rigid PVC and nano‐CaCO₃, and addition of nano‐CaCO₃ at the onset of PVC fusion were investigated. Dispersion of treated and untreated nano‐CaCO₃ was studied by X‐ray diffraction and scanning electron microscopy. Results showed that using direct dry mixing improved the dispersion of nano‐CaCO₃ in the PVC matrix by lowering the fusion time. The mechanical properties of the nanocomposite samples such as impact strength, tensile strength, and elongation at break were improved by using this method. The addition of treated nano‐CaCO₃ at the onset of fusion caused a simultaneous decrease in torque. Also, rigid PVC nanocomposites prepared with treated nano‐CaCO₃ showed better mechanical properties than those of nanocomposites prepared with the untreated nano‐CaCO₃. J. VINYL ADDIT. TECHNOL., 18:153–160, 2012. © 2012 Society of Plastics Engineers     

The preparation of core‐shell CaCO3 particles and its effect on mechanical property of PVC composites

In this study, a novel mechanochemical route to prepare core‐shell structured particles was introduced. XPS, TEM, and dissolving experimental results indicate the formation of [(inorganic particle)/(elastomer)] core‐shell structured particles, and several kinds of calcium carbonate (nano‐CaCO₃) particles with various interfaces were obtained. The mechanical properties and morphological results indicate that the surface treatment of nano‐CaCO₃ particles and the existence of outer elastic layer will strengthen the interfacial interaction between nano‐CaCO₃ particles and PVC matrix, which results in improvement of mechanical properties of PVC/CaCO₃ composites. The theoretical calculations of the interfacial interaction and DMA results confirm these especially when the surface of nano‐CaCO₃ particles was treated by MMA and coated in succession by ACR through vibro‐milling. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1084–1091, 2006     

Effect of nanocalcium carbonate on the impact strength and accelerated weatherability of rigid poly(vinyl chloride)/acrylic impact modifier

Poly(vinyl chloride) (PVC) composites filled with nano‐ and micro‐CaCO₃ particles were prepared via a melt blending method. Transmission electron microscopy images revealed better dispersion of nano‐CaCO₃ than micro‐CaCO₃ in the PVC matrix. With more than 5 phr (parts per 100 parts of resin) of nano‐CaCO₃ content, both impact strength and heat stability were improved. Accelerated weathering tests were performed to investigate UV stability. The impact strength and white index obtained upon weathering exposure of PVC/(80 μm CaCO₃) nanocomposites showed a significant improvement upon incorporating nano‐CaCO₃. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers     

Effect of High‐Energy Vibromilling on Interfacial Interaction and Mechanical Properties of PVC/Nano‐CaCO3 Composites

Summary: The effects of interfacial interaction between nano‐CaCO₃ and PVC on mechanical properties and morphology of PVC/nano‐CaCO₃ composites were studied. Nano‐CaCO₃ was treated with vibromilling in the presence of PVC and coupling agents. The mechanical properties of PVC/treated nano‐CaCO₃ are remarkably improved. Transmission electron microscopy results revealed that vibromilled nano‐CaCO₃ particles are well dispersed in PVC matrix with good homogeneity and well adhered to PVC matrix. Molau test indicated that chemical reaction between newly formed surface of nano‐CaCO₃ and PVC or coupling agent took place. Theoretical calculation results show that the interfacial interaction between PVC and nano‐CaCO₃ are substantially improved through vibromilling treatment of nano‐CaCO₃ in the presence of PVC and coupling agent.

Molau test results of the samples in THF.     

Preparation and characterization of nano‐CaCO3 encapsulated with polyacrylic and its application in PVC toughness

The properties and morphology of nano‐calcium carbonate (nano‐CaCO₃) modified with the titanate coupling agent isopropyl trioleoyl titanate (IPTT) were characterized by Fourier transform infrared, thermogravimetric analyses, surface tension, and transmission electron microscopy. The results showed that the grafting ratio of IPTT on the surface of nano‐CaCO₃ (IPTT‐Ca) increased with IPTT content. IPTT‐Ca/PBA/PMMA (IPTT‐Ca/ACR, PBA/PMMA core‐shell polymer, referred to ACR) latexes were prepared by seeded emulsion polymerization. They were then used to mix with PVC resin. The outer layer (PMMA) enhanced the dispensability of IPTT‐Ca/ACR in the PVC matrix by increasing the interfacial interaction of these composite particles with PVC. The notched impact strengths of the blends were influenced by the weight ratio of IPTT‐Ca to BA/MMA monomers, the weight ratio of BA/MMA. The relationships between the mechanical properties and the core‐shell composite structures were elaborated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and properties of HDPE/CaCO3/OMMT ternary nanocomposite

A series of binary composites based on HDPE (high density polyethylene) and nanoinorganic particles such as nano‐CaCO₃ and OMMT (organic montmorillonite) were prepared. Their properties including tensile, impact strength, and some thermal properties were tested. The results showed that binary composite has partial improvement in mechanical properties compared with pure HDPE. A ternary composite nano‐CaCO₃/OMMT/HDPE was prepared and characterized. It was found that the mechanical and thermodynamic properties of this ternary composite have been enhanced greatly compared with both pure HDPE and binary composites. The tensile strength, Young's modulus, flexural strength, elastic modulus, and impact strength of nano‐CaCO₃/OMMT/HDPE were increased 124.6%, 302.7%, 73.86%, 58.97%, and 27.25%, respectively. The DMA test results showed that the mechanical properties of ternary composite were increased because of the limitation on the movement of HDPE due to inorganic particles. The synergistic effect introduced by nanoparticles may play an important role in all these processes. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

Study on mechanical and flow properties of acrylonitrile‐butadiene‐styrene/poly(methyl methacrylate)/nano‐calcium carbonate composites

Acrylonitrile‐butadiene‐styrene (ABS)/poly(methyl meth‐acrylate) (PMMA)/nano‐calcium carbonate (nano‐CaCO₃) composites were prepared in a corotating twin screw extruder. Four kinds of nano‐CaCO₃ particles with different diameters and surface treatment were used in this study. The properties of the composites were analyzed by tensile tests, Izod impact tests, melt flow index (MFI) tests, and field emission scanning electron microscopy (FESEM). This article is focused on the effect of nano‐CaCO₃ particles' size and surface treatment on various properties of ABS/PMMA/nano‐CaCO₃ composites. The results show that the MFI of all the composites reaches a maximum value when the content of nano‐CaCO₃ is 4 wt%. In comparison with untreated nano‐CaCO₃ composites, the MFI of stearic acid treated nano‐CaCO₃ composites is higher and more sensitive to temperature. The tensile yield strength decreases slightly with the increase of nano‐CaCO₃ content. However, the size and surface treatment of nano‐CaCO₃ particles have little influence on the tensile yield strength of composites. In contrast, all of nano‐CaCO₃ particles decrease Izod impact strength significantly. Stearic acid treated nano‐CaCO₃ composites have superior Izod impact strength to untreated nano‐CaCO₃ composites with the same nano‐CaCO₃ content. Furthermore, the Izod impact strength of 100 nm nano‐CaCO₃ composites is higher than that of 25 nm nano‐CaCO₃ composites. POLYM. COMPOS., 31:1593–1602, 2010. © 2009 Society of Plastics Engineers     

Effects of poly(1,2‐propylene glycol adipate) and nano‐CaCO3 on DOP migration and mechanical properties of flexible PVC

Nano‐CaCO₃ was used as nano‐scale filler and poly(1,2‐propylene glycol adipate) (PPA) was used as polymeric plasticizer in flexible poly(vinyl chloride) (PVC) sheets for the partial replacement of di(2‐ethyl hexyl) phthalate (DOP) in this paper. The effect of PPA and nano‐CaCO₃ on restraining DOP migration was evaluated via extraction tests. The results showed that the introduction of nano‐CaCO₃ can decrease the extraction rate of DOP in the PVC matrix. The tensile strength and elongation at break of CaCO₃‐1/PPA‐20/DOP‐30/PVC were similar to those of DOP‐50/PVC, and CaCO₃‐1/PPA‐20/DOP‐30/PVC exhibited the superior suppression of DOP migration compared with DOP‐50/PVC. Thermogravimetry analysis (TGA) indicated that the addition of nano‐CaCO₃ effectively improved the thermal stability of the nanocomposites. Therefore, the combination of PPA and nano‐CaCO₃ is an effective approach to suppress the migration of DOP. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The experimental results and simulation of temperature dependence of brittle‐ductile transition in PVC/CPE blends and PVC/CPE/nano‐CaCO3 composites

The effect of chlorinated polyethylene (CPE) content and test temperature on the notched Izod impact strength and brittle‐ductile transition behaviors for polyvinylchloride (PVC)/CPE blends and PVC/CPE/nano‐CaCO₃ ternary composites is studied. The CPE content and the test temperature regions are from 0–50 phr and 243–363 K, respectively. It is found that the optimum nano‐CaCO₃ content is 15 phr for PVC/CPE/nano‐CaCO₃ ternary composites. For both PVC/CPE blends and PVC/CPE/nano‐CaCO₃ ternary composites, the impact strength is improved remarkably when the CPE content or test temperature is higher than the critical value, that is, brittle‐ductile transition content (C_BD) or brittle‐ductile transition temperature (T_BD). The T_BD is closely related to the CPE content, the higher the CPE content, the lower the T_BD. The temperature dependence of impact strength for PVC/CPE blends and PVC/CPE/nano‐CaCO₃ ternary composites can be well simulated with a logistic fitting model, and the simulation results can be illustrated with the percolation model proposed by Wu and Jiang. DMA results reveal that both PVC and CPE can affect the T_BD of PVC/CPE blends and PVC/CPE/nano‐CaCO₃ composites. When the CPE content is enough (20 phr), the CPE is more important than PVC for determining the T_BD of PVC/CPE blends and PVC/CPE/nano‐CaCO₃ composites. Scanning electron microscopy (SEM) observations reveal that the impact fractured mechanism can change from brittle to ductile with increasing test temperature for these PVC systems. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Improved mechanical properties and structure of PP/nano‐CaCO3 blends prepared by low‐frequency vibration injection molding

BACKGROUD: Melt vibration technology was used to prepare injection samples of polypropylene (PP)/nano‐CaCO₃ blends. It is well known that nano‐CaCO₃ particles are easy to agglomerate owing to their large surface energy. Improving the distribution of nano‐CaCO₃ particles in PP/nano‐CaCO₃ blends is very important for enhancing the mechanical properties. In this work, low‐frequency vibration was imposed on the process of injection molding of PP/nano‐CaCO₃ blends. The aim of importing a vibration field was to change the crystal structure of PP as we studied previously and improve the distribution of nano‐CaCO₃ particles. Furthermore, the mechanical properties were improved. RESULTS: Through melt vibration, the mechanical properties of PP/nano‐CaCO₃ samples were improved significantly. Compared with conventional injection molding, the enhancement of the tensile strength and impact strength of the samples molded by vibration injection molding was 17.68 and 175.96%, respectively. According to scanning electron microscopy, wide‐angle X‐ray diffraction and differential scanning calorimetry measurements, it was found that a much better dispersion of nano‐CaCO₃ in samples was achieved by vibration injection molding. Moreover, the crystal structure of PP in PP/CaCO₃ vibration samples changed. The γ crystal form was achieved at the shear layer of vibration samples. Moreover, the degree of crystallinity of PP in vibration samples increased 6% compared with conventional samples. CONCLUSION: Concerning the microstructure, melt vibration could effectively change the crystal structure and increase the degree of crystallinity of PP besides improving the distribution of nano‐CaCO₃ particles. Concerning the macrostructure, melt vibration could enhance the mechanical properties. The improvement of mechanical properties of PP/nano‐CaCO₃ blends prepared by low‐frequency vibration injection molding should be attributed to the even distribution of nano‐CaCO₃ particles and the formation of γ‐PP and the increase of the degree of cystallinity. Copyright © 2007 Society of Chemical Industry     

Influence of the compounding route on the properties of polypropylene/nano‐CaCO3/ethylene–propylene–diene terpolymer tercomponent composites

The influence of the compounding route of polypropylene (PP)/ethylene–propylene–diene terpolymer (EPDM)/nano‐CaCO₃ composites on their properties, including their mechanical properties, the dispersion degree of nano‐CaCO₃, and the morphology of EPDM, was studied. The results showed that the toughness of the composites and the morphology of the EPDM particles were markedly influenced by the compounding route, whereas the dispersion degree of nano‐CaCO₃ in the matrix was little influenced by the compounding route. The impact strength of composites prepared by one route was about 60 kJ/m² with 20 wt % nano‐CaCO₃. The results indicated that a sandbag of nano‐CaCO₃ embedded in EPDM could effectively improve the toughness of the composites. A sandbag composed of EPDM and nano‐CaCO₃ eliminated the deterioration effect of the nano‐CaCO₃ agglomerate on the toughness of the composites, whereas the nano‐CaCO₃ agglomerate separately dispersed in PP decreased the toughness of the tercomponent composite © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Effect of interfacial interaction on the crystallization and mechanical properties of PP/nano‐CaCO3 composites modified by compatibilizers

To investigate the effect of interfacial interaction on the crystallization and mechanical properties of polypropylene (PP)/nano‐CaCO₃ composites, three kinds of compatibilizers [PP grafted with maleic anhydride (PP‐g‐MA), ethylene–octene copolymer grafted with MA (POE‐g‐MA), and ethylene–vinyl acetate copolymer grafted with MA (EVA‐g‐MA)] with the same polar groups (MA) but different backbones were used as compatibilizers to obtain various interfacial interactions among nano‐CaCO₃, compatibilizer, and PP. The results indicated that compatibilizers encapsulated nano‐CaCO₃ particles, forming a core–shell structure, and two interfaces were obtained in the compatibilized composites: interface between PP and compatibilizer and interface between compatibilizer and nano‐CaCO₃ particles. The crystallization and mechanical properties of PP/nano‐CaCO₃ composites were dependent on the interfacial interactions of these two interfaces, especially the interfacial interaction between PP and compatibilizer. The good compatibility between PP chain in PP‐g‐MA and PP matrix improved the dispersion of nano‐CaCO₃ particles, favored the nucleation effect of nano‐CaCO₃, increased the tensile strength and modulus, but reduced the ductility and impact strength of composites. The partial compatibility between POE in POE‐g‐MA and PP matrix had little effect on crystallization and mechanical properties of PP/nano‐CaCO₃ composites. The poor compatibility between EVA in EVA‐g‐MA and PP matrix retarded the nucleation effect of nano‐CaCO₃, and reduced the tensile strength, modulus, and impact strength. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Selective particle distribution and mechanical properties of nano‐CaCO3/ethylene‐propylene‐diene terpolymer/polypropylene composites with high content of nano‐CaCO3

T ernary composite of nano‐CaCO₃/ethylene‐propylene‐diene terpolymer (EPDM)/polypropylene (PP) with high content of nano‐CaCO₃ was prepared by two step compounding route, in which EPDM and nano‐CaCO₃ were mixed first, and then melt compounding with PP matrix. The influence of mixing time during the second compounding on distribution of nano‐CaCO₃ particles and the impact strength of the ternary composite have been investigated. It was found that the Izod impact strength of composite decreased with increasing mixing time. The observation of transmission electron microscopy obviously showed that nano‐CaCO₃ particles transported from EPDM to PP matrix firstly and then from PP to the vicinity of EPDM dispersed phase with the increase of mixing time. This phenomenon can be well explained by the minimization of the dissipative energy and the Young's equation. The scanning electron microscope images show that lots of nano fibrils exist at the interface between nano‐CaCO₃ agglomerates and matrix, which can dissipate lots of energy. The toughening mechanism has been interpreted in terms of three‐stage‐mechanism: stress concentration, void and shear band formation, and induced shear yielding. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effects of inorganic nano‐particles on plasticizers migration of flexible PVC

The influences of nano‐particles (nano‐sized CaCO₃ and nano‐sized SiO₂) on plasticizers volatility, solvent extraction stability, and exudation stability of flexible PVC were studied. The results showed that nano‐particles could reduce migration of plasticizers, thus improved the ability of anti‐migration of flexible PVC. Further more, nano‐sized SiO₂ shows excellent property than nano‐sized CaCO₃ in resistance migration of plasticizers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Resin modification on interlaminar shear property of carbon fiber/epoxy/nano‐CaCO3 hybrid composites

Epoxy resin was modified by adding a silane coupling agent/nano‐calcium carbonate master batch. Then, samples of binary carbon fiber/epoxy composites and ternary fiber/nano‐CaCO₃/epoxy were prepared by hot press process. The interlaminar shear strength (ILSS) of the carbon fiber/epoxy composites was investigated and the results indicate that introduction of the treated nano‐CaCO₃ enhances ILSS obviously. In particular, the addition of 4 wt% nano‐CaCO₃ leads to 36.6% increase in the ILSS for the composite. The fracture surfaces of the carbon fiber/epoxy composites and the mechanical properties of epoxy resin cast are examined and both of them are employed to explain the change of ILSS. The results show that the change of ILSS is primarily due to an increase of the epoxy matrix strength and an increase of the fiber/epoxy interface. The bifurcation of propagating cracks, stress transfer, and cavitation are deduced for the reasons of strengthening and toughening effect of nano‐CaCO₃ particles. POLYM. COMPOS., 38:2035–2042, 2017. © 2015 Society of Plastics Engineers