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1.
Nanocomposites of poly(vinyl chloride), metallic oxides (copper, molybdenum, and zinc), and organically modified montmorillonite (O‐MMT) were prepared in a melt‐blending or intercalation‐in‐the‐molten state process, and their morphology was assessed with X‐ray diffraction and transmission electron microscopy. The formation of an intercalated/partially exfoliated hybrid microstructure was confirmed in every situation studied. The combustion and smoke emission properties were studied with cone calorimetry, limiting oxygen index, and thermogravimetry (TG) coupled with mass spectroscopy (MS). The results reveal that the metallic oxides had a significant effect on both the combustion properties and smoke suppression, whereas O‐MMT only affected these properties discretely. Little interaction was observed in the joint use of these additives. The results also confirm the anticipation of dehydrochlorination, reductive coupling, and benzene suppression mechanisms resulting from the presence of copper, molybdenum, and zinc metals; these were indicated by the increase in carbonaceous char residue and the significant reduction in benzene formation, in this case indicated in the TG/MS measurements obtained. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

2.
Research into organic–inorganic nanocomposites has recently become popular, particularly the development of new polymer nanocomposites. Compared to pristine polymers or conventional composites, these nanocomposites exhibit improved properties. The storage modulus of a poly(vinyl chloride) (PVC)/polyhedral oligomeric silsesquioxane (POSS) nanocomposite slightly decreased with POSS content, but had a higher modulus from 50 to 100 °C. Some of the material appeared to be aggregated with 1 wt% POSS in the polymeric matrix. Conversely, with a POSS content of 5 wt%, a better dispersion of the nanoparticles was observed. The presence of POSS in the plasticised PVC compound had little influence on the final properties of the nanocomposites, showing weaker interactions between the POSS and the plasticised PVC compound. Copyright © 2010 Society of Chemical Industry  相似文献   

3.
Effects of nanoscale dispersed layered double hydroxides (LDHs) on thermal stability of poly(vinyl chloride) (PVC) in thermal and thermooxidative degradation processes are investigated by dynamic and isothermal thermogravimetric analysis (TGA), discoloration test, fourier transform infrared (FTIR), and ultraviolet‐visible (UV‐vis) spectroscopic techniques. During both stages of thermal degradation, the degradation temperatures, including onset degradation temperature and temperature of the maximum degradation rate, increase, and the final residue yield of the PVC/LDH nanocomposites reaches 14.7 wt %, more than double that for neat PVC. The thermooxidative degradation process is more complex. During the first two stages, the presence of nanoscale dispersed LDH particles enhances the thermal stability, whereas in the last stage accelerates the thermal degradation possibly due to the accumulation of heat released. Additionally, the studies of the isothermal thermooxidative degradation process by FTIR and UV‐vis spectra indicate that both polyene backbone formation and some carbonyl groups are simultaneously developed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

4.
A dimethyl dioctadecyl ammonium chloride modified organic montmorillonite (OMMT‐I.44P)/poly(vinyl chloride) (PVC) nanocomposite and anionic‐surfactant‐modified lanthanum organic montmorillonite (La‐OMMT)/PVC nanocomposites (with three different anionic surfactants for the La‐OMMTs) were prepared via melt‐intercalation technology. The effects of the La‐OMMTs and OMMT‐I.44P on the mechanical properties, flame retardancy, and smoke suppression of PVC were studied. X‐ray diffraction characterization showed that the La‐OMMTs were exfoliated in the PVC matrix. The mechanical properties of the nanocomposites were enhanced by the incorporation of the La‐OMMTs. Cone calorimetry and gas chromatography–mass spectrometry analyses indicated that the incorporation of the La‐OMMTs enhanced the flame retardancy and smoke suppression of the PVC nanocomposites. Scanning electron microscopy photos further showed that the residual char surfaces of La‐OMMT/PVC were all intact and, thus, provided better barriers to energy and smoke transport. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43951.  相似文献   

5.
Montmorillonite (MMT) was organically modified with tributyl citrate (TBC). Organoclays (OMMTs) were processed with diisononyl phthalate (DINP)‐plasticized polyvinyl chloride (PVC) to form polymer nanocomposites. The produced composite materials showed a contradictory change in properties to that expected of a layered silicate nanocomposite, with a decreased E‐modulus and increased gas permeability compared with a material without OMMT. It was experimentally shown that the TBC modifier was extracted from the OMMT and was dispersed in the PVC/DINP matrix, whereupon the OMMT collapsed and formed micrometer‐sized agglomerates. Further investigation revealed that TBC has a significant effect on the gas permeability and the E‐modulus, even at low additions to a DINP‐plasticized PVC. A PVC nanocomposite with the TBC acting as both the OM for MMT and as the primary plasticizer was produced. This material showed a significantly increased E‐modulus as well as a decrease in gas permeability, confirming that it is possible to develop a nanocomposite based on plasticized PVC, if both the organo‐modification of the MMT and the formulation of the matrix are carefully selected. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42876.  相似文献   

6.
Poly(vinyl alcohol) (PVA)/montmorillonite clay (MMT) nanocomposites in the form of films were prepared under the effect of electron beam irradiation. The PVA/MMT nanocomposites gels were characterized by X‐ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and mechanical measurements. The study showed that the appropriate dose of electron beam irradiation to achieve homogeneous nanocomposites films and highest gel formation was 20 kGy. The introduction of MMT (up to 4 wt %) results in improvement in tensile strength, elongation at break, and thermal stability of the PVA matrix. In addition, the intercalation of PVA with the MMT clay leads to an impressive improved water resistance, indicating that the clay is well dispersed within the polymer matrix. Meanwhile, it was proved that the intercalation has no effect on the metal uptake capability of PVA as determined by a method based on the color measurements. XRD patterns and SEM micrographs suggest the coexistence of exfoliated intercalated MMT layers over the studied MMT contents. The DSC thermograms showed clearly that the intercalation of PVA polymer with these levels of MMT has no influence on the melting transitions; however, the glass transition temperature (Tg) for PVA was completely disappeared, even at low levels of MMT clay. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1129–1138, 2006  相似文献   

7.
A series of poly(vinyl chloride) (PVC)/green coconut fiber (GCF) composites, with dioctyl phthalate (DOP) or thermoplastic polyurethane (TPU) as a plasticizer, were prepared by melt mixing. Their properties were studied in the molten state with an advanced nonlinear harmonic testing technique; in the solid state, the hardness and impact resistance were evaluated, and scanning electron microscopy was used for fractured surfaces. The effect of the fiber loading was investigated, as well as the role of the plasticizer. PVC–GCF composites are heterogeneous materials that, in the molten state, exhibit essentially a nonlinear viscoelastic character, in contrast to pure PVC, which has a linear viscoelastic region up to 50–60% strain. The complex modulus increases with the GCF content but in such a manner that the observed reinforcement is at best of hydrodynamic origin, without any specific chemical (i.e., permanent) interaction occurring between the polymer matrix and the fibers. As expected, PVC offers good wetting of GCFs, as reflected by the easy mixing and the rheological and mechanical properties. Fibers can be incorporated into PVC up to a 30% concentration without any problem, with the PVC/plasticizer ratio kept constant. Higher GCF levels could therefore be considered. Replacing DOP in part with TPU gives some benefit in terms of impact resistance, likely because of the viscoelastic nature of the latter and the associated energy absorption effects. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007  相似文献   

8.
Blends were prepared of poly(vinyl chloride) (PVC) with four different plasticizers; esters of aconitic, citric, and phthalic acids; and other ingredients used in commercial flexible PVC products. The thermal and mechanical properties of the fresh products and of the products after 6 months of aging were measured. Young's modulus of the PVC blends was reduced about 10‐fold by an increase in the plasticizer level from 15 to 30 phr from the semirigid to the flexible range according to the ASTM classification, but a 40‐phr level was required for PVC to retain its flexibility beyond 6 months. At the 40‐phr level, tributyl aconitate performed better than diisononyl phthalate (DINP) or tributyl citrate, in terms of lowering Young's modulus, both in the fresh materials and those aged for 6 months. The effects of the four plasticizers on the glass‐transition temperature (Tg) were similar, with Tg close to ambient temperature at the 30‐ and 40‐phr levels in freshly prepared samples and at 40–60°C in those aged for 6 months. The thermal stability of the PVC plasticized with DINP was superior among the group. Overall, tributyl aconitate appeared to be a good candidate for use in consumer products where the alleged toxicity of DINP may be an issue. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1366–1373, 2006  相似文献   

9.
A novel layered double hydroxide/NaSb(OH)6‐based nanocomposite (Sb‐LDH) has been prepared via intercalation of thio‐antimonite (SbS33?) and reconstruction of LDH using Mg‐Al LDH as precursors. It is composed of LDH nanolayers with thickness of 25 nm and NaSb(OH)6 nanoparticles with diameter of 3–25 nm. The presence of NaSb(OH)6 will decrease the decomposition intensity and hinder the decomposition of Mg‐Al LDH because of the potential synergetic effect. When applied to poly(vinyl chloride) (PVC) composites, both Mg‐Al LDH and Sb‐LDH can enhance the thermal stability and increase the decomposition temperature of PVC. Compared with Mg‐Al LDH, Sb‐LDH results in higher decomposition temperatures and whiteness and higher initial and long‐term stabilities due to the presence of NaSb(OH)6, which can react with HCl and coordinate with Cl in the PVC chains. Because Mg‐Al LDH will accelerate the dehydrochlorination of PVC driving by the Lewis acid such as AlCl3, the thermal stability of PVC decreases with increasing nanofiller loading. When 1 wt % Sb‐LDH was added, the color change time and Congo red time of PVC composites are 140 min and 154 min, respectively. With enhanced thermal stabilization, this novel LDH nanocomposite could gain promising application in thermal stabilizer for PVC resins. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

10.
PVC/Na+–montmorillonite (MMT) nanocomposites were prepared via a simple technique of emulsion polymerization at several different MMT clay concentrations. X‐ray diffraction and transmission electron microscopy studies revealed the formation of a mixture of intercalated and exfoliated nanostructure. Tensile testing results showed that the tensile modulus of the nanocomposites increased with the addition of clay, while the tensile strength decreased little. The notched impact strength of the nanocomposites was also improved. For systems containing clay in the range of 2.1 to 3.5 wt %, the impact strength was almost two times as large as that of pure PVC. However, those mechanical properties began to decrease with the continuously increasing amount of clay. The fracture surface of pure PVC and the nanocomposites was observed by scanning electron microscope. Thermal properties of the nanocomposites were found to increase as a result of clay incorporation. The glass transition temperatures of the PVC/clay nanocomposites were nearly identical to that of pure PVC. The Vicat softening points exhibited a progressively increasing trend with the clay content added. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 277–286, 2004  相似文献   

11.
Effects of three different plasticizers and their blends with dioctyl phthalate (DOP) on thermal stability, flammability, mechanical, electrical, and permanence properties of poly(vinyl chloride) (PVC) compound were studied. Various plasticizers used were DOP, butyl benzyl phthalate (BBP), isodecyl diphenyl phosphate (IDDP), and polybutylene adipate (PBA) at concentrations of up to 40 phr level. Studies showed that processability and softness were improved by addition of BBP. An increase in the content of IDDP increased the electrical and flammability properties, whereas compositions with PBA exhibited the best permanence properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3278–3284, 2003  相似文献   

12.
Mechanical properties and thermal and structural changes of poly(vinyl chloride) (PVC)/wood sawdust composites were assessed with respect to the effect of moisture content, varying from 0.33 to 3.00 % by weight in the composite, for three different wood sawdust contents. The swell ratio and texture characteristics of the composite extrudates were also evaluated. Unique explanations were given to describe changes in the composite properties in terms of molecular interactions between PVC, cellulosic sawdust and moisture, such as dipole–dipole interactions, interfacial defects and bonding, fibre swelling, and moisture evaporation. The results suggest that at low moisture content the tensile modulus decreased and elongation at break of the composites increased with moisture content, the effect being reversed for high moisture content. Tensile strength decreased with increasing moisture content up to 1–2 %, and then unexpectedly increased at higher moisture contents. The effect of moisture content on flexural properties of the composite was similar to that on tensile properties. Impact strength of the composites was considerably improved with moisture content at low sawdust contents (16.7 wt%), and was independent of the moisture content at higher sawdust contents (28.6 and 37.5 wt%). A decrease in decomposition temperature with an increase in polyene content was evidenced with increasing moisture content, while the glass transition temperature did not change with varying moisture content. The extrudate swell ratio increased with the shear rate but remained unaffected by moisture content. The bubbling and peeling‐off in the composite extrudate occurred as a result of the evaporation of water molecules and the application of a high shear rate. Copyright © 2004 Society of Chemical Industry  相似文献   

13.
Poly(vinyl chloride)(PVC) and dioctyl phthalate (DOP) were mixed with 5 and 10 wt % of Cloisite Na+, Cloisite 30B or Cloisite 93A. The obtained nanocomposites were characterized by thermal analysis using a thermogravimetric analyzer which showed that addition of 5 wt % of nanoclay to PVC increased its thermal stability in the sequence: Cloisite Na+< Cloisite 93A< Cloisite 30B. The electrical conductivity of these composites was studied as a function of temperatures and showed that the conductivity of PVC was enhanced upon using 5 wt % of nanoclay in the sequence: Cloisite Na+< Cloisite 30B < Cloisite 93A. The activation energy of interaction of PVC with nanoclay was found to be lowest for the composite containing 5 wt % of nanoclay in the same sequence. The tensile strength, elongation (%), and Young's modulus were considerably enhanced upon increasing the clay content to 5 wt % in the sequence: Cloisite Na+< Cloisite 93A < Cloisite 30B. X‐ray diffraction (XRD) and scanning electron microscopy (SEM) were used to study these nanocomposite structures, and it was found that the organoclay layers are homogeneously dispersed in the PVC matrix when 5 wt % of Cloisite 30B or Cloisite 93A was used. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

14.
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  相似文献   

15.
Nanosilica particles are functionalized by in situ surface‐modification with trimethyl silane and vinyl silane. Resultant reactive nanosilica (coded as RNS) contains double bonds and possesses good compatibility with vinyl chloride (VC) and polyvinyl chloride (PVC). This makes it feasible for RNS to copolymerize with VC generating RNS/PVC composites via in situ suspension polymerization. As‐prepared RNS/PVC composite resins are analyzed by means of FTIR. The tensile strength and impact strength of compression‐molded RNS/PVC composites are measured and compared with that of compression‐molded PVC composites doped with dispersible nano‐SiO2 particles (abridged as DNS) surface‐modified with trimethyl silane alone. Moreover, the thermal stability of compression‐molded RNS/PVC and DNS/PVC composites is evaluated by thermogravimetric analysis. It has been found that RNS/PVC composites possess greatly increased impact strength and tensile strength than PVC matrix, while DNS/PVC composites possess higher impact strength than PVC matrix but almost the same tensile strength as the PVC matrix. This implies that DNS is less effective than RNS in improving the mechanical strength of PVC matrix. Particularly, RNS/PVC composites prepared by in situ suspension polymerization have much higher mechanical strength than RNS/PVC composites prepared by melt‐blending, even when their nanosilica content is only 1/10 of that of the melt‐blended ones. Besides, in situ polymerized RNS/PVC and DNS/PVC composites have better thermal stability than melt‐blended nanosilica/PVC composites. Hopefully, this strategy, may be extended to fabricating various novel high‐performance polymer‐matrix composites doped with organically functionalized nanoparticles like RNS. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

16.
This article describes the development of novel nanocrystalline poly(vinyl chloride) (PVC) for potential applications in PVC processes and reports improvements in the mechanical properties and thermal resistance. Before the preparation of nanocrystalline PVC via jet milling, PVC was spray‐treated and heat‐treated to improve its crystallinity. The pulverization and degradation, morphology, crystalline structure, and melting‐point changes of postmodified PVC during jet milling and the relationship between the distributions of the particle size and processing temperature were investigated. X‐ray analysis and density testing indicated increased density and improved crystallinity. The crystalline region of nanocrystalline PVC was less than 80 nm, with a particle size distribution of 5–20 μm and a melting point of less than 128°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 563–569, 2004  相似文献   

17.
Thermal stability of polyvinyl chloride (PVC) based montmorillonite composites with either sodium montmorillonite (MMT) or alkyl ammonium ion modified montmorillonite (OMMT) were investigated by thermogravimetric analysis. The apparent activation energies associated with the first thermal degradation stage were calculated by the methods of Flynn–Wall–Ozawa and Kissinger in nitrogen atmosphere at several different heating rates. The processing thermal stability of PVC and PVC/MMT(OMMT) composites was also discussed. Increase of mixing torque did not result in a larger intercalation extent of PVC on MMT; instead, it unexpectedly induced discoloration of PVC and then deteriorated the processing stability, especially in the presence of OMMT. The apparent activation energies in the first thermal degradation stage exhibited little difference among PVC, PVC/MMT, and PVC/OMMT composites, and the kinetic compensation effect of Sp* kept a constant value, indicating that the thermal stability and thermal degradation mechanism of PVC were not affected by the presence of either MMT or OMMT, although the processing discoloration of PVC is observed for PVC/OMMT composite. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1521–1526, 2004  相似文献   

18.
In this study, a novel ‐intercalated layered double hydroxide (Sb‐LDH) was prepared by simultaneous recovering of LDH structures and intercalation of into LDH layers. The prepared Sb‐LDH composites remain the hydrotalcite structure with layered geometry and show higher thermal property than that of LDH. When applied to poly(vinyl chloride) (PVC) composites, Sb‐LDH showed limited thermal stability for PVC at the early stage of thermal and thermooxidative degradation processes. However, Sb‐LDH could retard the thermal cracking of the carbonaceous conjugated polyene of PVC which may hinder further degradation, and the moderate amount of Sb‐LDH (1, 2, and 5 wt %) in PVC resin can retard the process of decarbonation and enhance char formation. Sb‐LDH also promoted the transparency of PVC but darkened the color. With the advantages of transparency promotion, high temperature resistance, and long‐term stability, the prepared Sb‐LDH is a potential thermal stabilizer for PVC resins. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42524.  相似文献   

19.
Poly(methyl methacrylate) (PMMA)/montmorillonite (MMT) nanocomposites were synthesized by a simple technique of a monomer casting method, bulk polymerization. The products were purified by hot acetone extraction and characterized by Fourier transform infrared spectroscopy, X‐ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), examination of their mechanical properties, and light transmittance testing. Although XRD data did not show any apparent order of the MMT layers in the nanocomposites, TEM revealed parallel MMT layers with interlamellar spacings of an average of 9.8 nm and the presence of remnant multiplets of nonexfoliated layers. Therefore, PMMA chains were intercalated in the galleries of MMT. DSC and TGA traces also corroborated the confinement of the polymer in the inorganic layer by exhibiting the increase of glass‐transition temperatures and mass loss temperatures in the thermogram. Both the thermal stability and the mechanical properties of the products appeared to be substantially enhanced, although the light transmittances were not lost. Also, the materials had excellent mechanical properties. Measurement of the tensile properties of the PMMA/MMT nanocomposites indicated that the tensile modulus increased up to 1013 MPa with the addition of 0.6 wt % MMT, which was about 39% higher than that of the corresponding PMMA; the tensile strength and Charpy notched impact strength increased to 88 MPa and 12.9 kJ/m2, respectively. As shown by the aforementioned results, PMMA/MMT nanocomposites may offer new technology and business opportunities. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 348–357, 2005  相似文献   

20.
The processability, rheology, and thermal, mechanical, and morphological properties of three different commercial poly(vinyl chloride) (PVC) compounds blended with postconsumer PVC bottles and PVC cables were examined with respect to the recycled PVC content. The addition of PVC bottle recyclates [recycled bottles (RBs)] into virgin PVC bottle (VB) and virgin PVC pipe (VP) compounds caused a progressive reduction in the average torque. No thermal degradation or color change in the RB‐blended PVC compounds used was detected through carbonyl and polyene indices from IR analysis. The rheological properties for VP compounds were more sensitive to RB addition than those of VB compounds. The extrudate swell ratio did not change with the RB content. The decomposition temperature for the VB and VP compounds increased at 60–80% RB, whereas the glass‐transition temperature was unaffected by the RB loading. The 20 and 80 wt % RB loadings were recommended for the VB and VP compounds, respectively, for the optimum impact strength, the blends showing ductile fracture with a continuous phase. At the optimum impact and tensile properties, introducing RB recyclates into the VB compounds gave better results than the VP compounds. The hardness and density of the VB and VP compounds did not change with the RB content. The RB property change was comparatively faster than that of recycled PVC pipes. Adding the PVC cable recyclate [recycled cable (RC)] to virgin PVC cable (VC) had no obvious effect on the torque value of the RC/VC blends. The decomposition temperatures of the RC/VC blends stabilized at 20–60% RC and tended to decrease at 80% RC. The ultimate tensile stress was improved by the addition of the RC compounds, whereas the hardness and density of the VC compounds were unaffected by the RC content. It was concluded that the optimum concentrations of PVC recyclates to be added to virgin PVC compounds were different from one property to another and also depended on the type of virgin PVC grade used. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2738–2748, 2003  相似文献   

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