Structure development in PP/CaSO2 composites: Part II Effect of filler on crystallization and morphology
TL;DR: The structure development in melt crystallized polypropylene (PP) containing different types and concentration of calcium sulphate has been studied by X-ray diffraction and optical polarizing microscopy as discussed by the authors.
Abstract: The structure development in melt crystallized polypropylene (PP) containing different types and concentration of calcium sulphate has been studied by X-ray diffraction and optical polarizing microscopy The commercial CaSO4 containing mostly the anhydrite form gives the α form of PP while the CaSO4 prepared by in situ method yields the β form of PP This takes place first by conversion of the dihydrate form of CaSO4 to the τ form which preferentially nucleates the β form of PP The crystallization behaviour in the latter case clearly reveals two processes The presence of PEO which is used for the in situ preparation of CaSO4, however, is found to hinder the rate of crystallization and nucleation of β the form of PP but it gives a high degree of orientation of the CaSO4 needle-like crystals during extrusion of the PP–CaSO4 composites © 1998 Chapman & Hall
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15 Aug 2005-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, thermal and mechanical properties of polypropylene nanocomposite were evaluated and a three-parameter nonlinear constitutive equation was developed to describe strain rate depend strain softening behavior.
Abstract: In the present paper, thermal and mechanical behavior of neat polypropylene, 40 wt.% talc-filled polypropylene and 5 wt.% silicate-clay filled polypropylene nanocomposite were tested and evaluated. TGA and DSC results show that filling the talc particle or nano clay into polypropylene can increase the decomposition temperature, but has no effect on glass transition temperature and melt temperature. Tensile results show that 40 wt.% talc particle can increase the modulus, but decrease the yield strength, 5 wt.% nano clay can improve both modulus and yield strength by 90 and 5%, respectively. Fatigue results show that the nanophased polypropylene exhibited the highest fatigue performance, and fatigue strength coefficient, σ f , of nanophased polypropylene was 13.3% higher than that of the neat propyropylene and 50% higher than that of talc-filled polypropylene. At last, a three-parameter non-linear constitutive equation was developed to describe strain rate depend strain softening behavior of three materials.
143 citations
TL;DR: In this article, the elegant approach of in situ deposition technique was used for the synthesis of nano CaCO3, which was confirmed by the X-ray diffraction (XRD) technique.
Abstract: The elegant approach of in situ deposition technique was used for the synthesis of nano CaCO3. the nanosize of particles was confirmed by the X-ray diffraction (XRD) technique. Differential scanning calorimetry (DSC) was used for determination of the enthalpy. The nano CaCO3 polypropylene (PP) composites were prepared by taking 2 and 10 wt % of different nanosizes (21–39 nm) of CaCO3. Conversion of the α phase to β was observed in the case of 2 wt % of a 30-nm sized amount of CaCO3 in a PP composite. The decrement in ΔH and percent crystallinity, as well as the increment in melt temperature were recorded for 6 wt % nano CaCO3 with a decrease in nanosize from 39 to 21 nm. The increment in tensile strength with an increase in the amount of nano CaCO3 was observed, and the lower particle size showed greater improvement. The improvement in thermal and mechanical properties is because of the formation of a greater number of small spherulites uniformly present in the PP matrix. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 107–113, 2004
128 citations
TL;DR: In this article, a polypropylene-Mg(OH)2 composite was prepared by melt-extrusion processing, and its size was confirmed by X-ray diffraction.
Abstract: Nano-Mg(OH)2 was synthesized with an in situ deposition technique, and its size was confirmed by X-ray diffraction. A polypropylene–Mg(OH)2 composite was prepared by melt-extrusion processing. The addition of a small quantity of a nanofiller (up to 10 wt %) increased Young's modulus up to 433% with respect to the modulus of virgin polypropylene. The addition of up to 4 wt % Mg(OH)2 produced the maximum increase, and a further decrease in the tensile strength was observed with an increase in the concentration of nano-Mg(OH)2. Increases in the hardness and other properties were due to higher nucleation and the intercalation of polymer chains in the nanolayer galleries. The flame-retarding property was demonstrated by the rate of burning. The time required to burn the nanofilled composite was greater than the time required for virgin polypropylene. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 116–122, 2004
82 citations
TL;DR: In this paper, the tensile behavior of polypropylene and 40 w% talc-filled polypropylenes was determined at four different temperatures (21.5, 50, 75 and 100°C) and three different strain rates (0.05, 0.5 and 5 min -1 ).
Abstract: The tensile behavior of unfilled and 40 w% talc-filled polypropylene has been determined at four different temperatures (21.5, 50, 75 and 100°C) and three different strain rates (0.05, 0.5 and 5 min -1 ). Experimental results showed that both unfilled and talc-filled polypropylenes were sensitive to strain rate and temperature. Stress-strain curves of both materials were nonlinear even at relatively low strains. The addition of talc to polypropylene increased the elastic modulus, but the yield strength and yield strain were reduced. The temperature and strain rate sensitivities of these materials were also different. An energy-activated, rate sensitive Eyring equation was used to predict the yield strength of both materials. It is shown that both activation volume and activation of energy increased with the addition of talc in polypropylene.
69 citations
TL;DR: In this article, a nanosize CaCO3 filler was synthesized by an in situ deposition technique, and its size was confirmed by X-ray diffraction, and three different sizes (21, 15, and 9 nm) of nano-CaCO3 were prepared in three different types of styrene-butadiene rubber (SBR) composites.
Abstract: A nanosize CaCO3 filler was synthesized by an in situ deposition technique, and its size was confirmed by X-ray diffraction CaCO3 was prepared in three different sizes (21, 15, and 9 nm) Styrene–butadiene rubber (SBR) was filled with 2–10 wt % nano-CaCO3 with 2% linseed oil as an extender Nano-CaCO3–SBR rubber composites were compounded on a two-roll mill and molded on a compression-molding machine Properties such as the specific gravity, swelling index, hardness, tensile strength, abrasion resistance, modulus at 300% elongation, flame retardancy, and elongation at break were measured Because of the reduction in the nanosize of CaCO3, drastic improvements in the mechanical properties were found The size of 9 nm showed the highest increase in the tensile strength (389 MPa) in comparison with commercial CaCO3 and the two other sizes of nano-CaCO3 up to an 8 wt % loading in SBR The elongation at break also increased up to 824% for the 9-nm size in comparison with commercial CaCO3 and the two other sizes of nano-CaCO3 Also, these results were compared with nano-CaCO3-filled SBR without linseed oil as an extender The modulus at 300% elongation, hardness, specific gravity, and flame-retarding properties increased with a reduction in the nanosize with linseed oil as an extender, which helped with the uniform dispersion of nano-CaCO3 in the rubber matrix © 2005 Wiley Periodicals, Inc J Appl Polym Sci 98: 2563–2571, 2005
67 citations
References
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01 Jan 1995
TL;DR: In this article, the structure and properties of polypropylene copolymers have been investigated in the context of fiber reinforced polypropylenes and fiber mat reinforced composite composites.
Abstract: Volume 1: Polymorphism in polypropylene homo- and copolymers. Molecular structure of polypropylene homo- and copolymers. Crystalline structures of polypropylene homo- and copolymers. Crystallisation, melting and supermolecular structure of isotactic polypropylene. Nucleation of polypropylene. Epitaxial growth on and with polypropylene. Processing-induced structure. Higher order structure of injection-moulded polypropylene. Knit-line behaviour of polypropylene and polypropylene-blends. Welding and fracture of polypropylene interfaces. Self-reinforcement of polypropylene. Processing-induced structure formation. Volume 2: Manufacturing and properties of polypropylene copolymers. Primary spherulite nucleation in polypropylene-based blends and copolymers. Polypropylene alloys and blends with thermoplastics. Structure and properties of polypropylene-elastomer blends. Oriental drawing of polypropylene and its blends. Thermoplastic elastomers by blending and dynamic vulcanization. Index. Volume 3: Particulate-filled polypropylene: structure and properties. Processing and properties of reinforced polypropylenes. Fibre orientation prediction in injection moulding. Microstructural aspects of fracture in polypropylene and in its filled, chopped fibre and fibre mat reinforced composites. Glass mat reinforced polypropylene. Some wetting and adhesion phenomena in polypropylene composites. Manufacturing methods for long fibre reinforced polypropylene sheets and laminates. Thermoforming of unidirectional continuous fibre-reinforced polypropylene laminates and their modelling. Fracture performance of continuous fibre reinforced polypropylene. Interfacial crystallization of polypropylene in composites. Index.
677 citations
Book•
30 Nov 1987
TL;DR: In this article, the authors present a review of the state-of-the-art techniques used by manufacturers of plastics products and fillers, plastics designers, engineers and polymer chemists.
Abstract: This book should be of interest to manufacturers of plastics products and fillers, plastics designers, engineers and polymer chemists.
445 citations
TL;DR: Using neutron diffraction data, the crystal structure of gypsum has been refined by Fourier and least squares methods in this article, and the hydrogen bond distance was found to be 2.82 A rather than 2.71 A.
Abstract: Using neutron diffraction data, the crystal structure of gypsum has been refined by Fourier and least squares methods. The hydrogen bond distance was found to be 2.82 A rather than 2.71 A, reported previously. The hydrogen positions are consistent with those obtained from nuclear magnetic resonance. The O–H distance is 0.99±0.03 A, and it appears that the O, H, O atoms are collinear. Infrared and Raman results are discussed in terms of the refined structure.
124 citations
TL;DR: In this article, a study was carried out to investigate molecular orientation in injection moulded bars of short glass fibre reinforced polypropylene and polyethylene and found that the fibres do not appear to have any direct effect on the matrix orientation.
78 citations
Book•
01 Jan 1994
TL;DR: Sommaire as mentioned in this paper describes the fabrication of polymer composites and the mechanical properties of composites, i.e., macromechanics, elasticity, and mechanical properties.
Abstract: Sommaire : 1.Fibrous reinforcements for composite materials. 2.Matrices. 3.Fabrication of polymer composites. 4.Mechanical properties of composites - micromechanics. 5.Mechanical properties - macromechanics. 6.Environmental aspects
60 citations