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1.
PVC/Blendex/Nano‐CaCO3 composites were prepared by melt‐blending method. The Blendex (BLENDEX® 338) (GE Specialty Chemicals Co., Ltd., Shanghai, China) was an acrylonitrile‐butadiene‐styrene copolymer with high butadiene content. The fracture behavior of PVC/Blendex/nano‐CaCO3 composites was studied using a modified essential work of fracture model, U/A = u0 + udl, where u0 is the limiting specific fracture energy and ud is the dissipative energy density. The u0 of PVC/Blendex blend could be greatly increased by the addition of nano‐CaCO3, while the ud was decreased. Nano‐CaCO3 with particle size of 38 nm increased the u0 of PVC/Blendex blend more effectively than that with particle size of 64 nm, when nano‐CaCO3 content was below 10 phr. Both the u0 and ud of PVC/Blendex/nano‐CaCO3 composites were not much affected by increasing specimen thickness from 3 mm to 5 mm, while the two fracture parameters were increased with increasing loading rate from 2 mm/min to 10 mm/min, and ud was found to be more sensitive to the loading rate than u0. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 953–961, 2005  相似文献   

2.
Polymer blends typically are the most economical means to develop new resins for specific applications with the best cost/performance balance. In this paper, the mechanical properties, melting, glass transition, and crystallization behavoir of 80 phr polypropylene (PP) with varying weights of linear low density polyethylene (LLDPE) at 10, 20/ 20 wt % CaCO3, 30, 40, and 50 phr were studied. A variety of physical properties such as tensile strength, impact strength, and flexural strength of these blends were evaluated. The compatibility of these composite was examined by differential scanning calorimetry (DSC) to estimate Tm and Tc, and by dynamic mechanical analysis (DMA) to estimate Tg. The fractographic analysis of these blends was examined by scanning electron microscopy (SEM). It has been confirmed that increasing the LLDPE content trends to decreases the tensile strength and flexural strength. However, increasing the LLDPE content led to increases in the impact strength of PP/LLDPE blends. It was also found that up to 40 phr the corresponding melting point (Tm) was not effected with increasing LLDPE content. Each compound has more than one Tg, which was informed that there is a brittle‐ductile transition in fracture nature of these blends, the amount of material plastically deformed on the failure surface seems to increase with the increasing the LLDPE content. And PP/LLDPE blends at temperature (23°C) showed a ductile fracture mode characterized by the co‐existence of a shear yielding process; whereas at lower temperature (−20°C) the fractured surfaces of specimens appear completely brittle. The specimens broke into two pieces with no evidence of stress whitening, permanent macroscopic deformation or yielding. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

3.
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.  相似文献   


4.
In this work, nano‐CaCO3 was used to improve the foamability of carbon fiber (CF)/polypropylene (PP) composite in solid‐state foaming using supercritical CO2. The CF content was maintained at 15 wt% and four concentrations of nano‐CaCO3 content, 1, 3, 5 and 8phr, were used. The surface of nano‐CaCO3 was firstly treated by silane coupling agent. By the way, the properties of the nano‐composites with various nano‐CaCO3 contents were analyzed by scanning electron microscope (SEM), differential scanning calorimeter (DSC), and torque rheometer. Before foaming, the gas absorption experiment was done using gravimetric method. Concerning on determination of the foaming conditions, it is found that 175°C and 60s were suitable as foaming temperature and time. Furthermore, we can also find that the foamed composites with 3phr nano‐CaCO3 showed the smallest mean cell diameter and largest cell density compared with the other nano‐CaCO3 contents under the given saturation condition. In addition, the mean cell diameter decreased while cell density increased as saturation pressure increased because of the higher gas solubility in the composites. When the saturation pressure was 25MPa, the mean cell diameter and cell density with 3phr nano‐CaCO3 were 17μm and 2.20×107cells/cm3, respectively. POLYM. COMPOS., 35:1723–1735, 2014. © 2013 Society of Plastics Engineers  相似文献   

5.
Summary: Polyoxymethylene (POM)/elastomer/filler ternary composites were prepared, in which thermoplastic polyurethane(TPU) and an inorganic filler, CaCO3, were used to achieve balanced mechanical properties of POM. A two‐step processing method, in which the elastomer and the filler were mixed to a masterbatch first and then the masterbatch was melt‐blended with pure POM, was used to obtain a core‐shell microstructure with CaCO3 covered by TPU. A brittle‐ductile transition phenomenon was observed with increasing TPU content for this ternary system. To better understand the toughening mechanism, we investigated the fractured surface, interparticle distance, and the spherulite size of POM as function of the TPU and CaCO3 content. The critical TPU content depended on not only the content of CaCO3, but also the size of CaCO3 particles. The observed brittle‐ductile transition was discussed based on the crystallinity and spherulite size of POM as well as Wu's critical interparticle distance theory. The results showed that the impact strength of POM/TPU/CaCO3 ternary system depends on a critical, interparticle distance, which varies from one system to another. The dependence of the impact strength on the spherulite size was considered for the first time, and a single curve was constructed. A critical spherulite size of 40 micron was found, at which brittle‐ductile transition occurs, regardless of the TPU and CaCO3 content or the size of CaCO3 particles. Our results indicate that the spherulite size of POM indeed plays a role in determining the toughness, and must be considered when discussing the toughening mechanism.

Izod impact strength vs. the crystal size for POM/TPU blends and POM/TPU/CaCO3 ternary composites.  相似文献   


6.
The impact properties of core‐shell acrylate (CS‐ACR)/chlorinated polyethylene (CPE)/poly(vinyl chloride) (PVC) blends under different temperatures were investigated. The fracture surface morphologies of the blends were observed by scanning electron microscopy (SEM). The results show that there exists significant synergistic effect between CS‐ACR particles and CPE in toughening PVC, and the impact properties of the blends generally correlate well with SEM morphologies. Besides, with increasing CS‐ACR content, ductile–brittle transition point of the ternary blends remarkably shifts to a lower temperature. Dynamic mechanical analysis exhibited that intensity and area of low‐temperature tan δ peaks of the CPE/PVC blends increase obviously after the addition of CS‐ACR particles, which to some extent are just in line with the changes in impact strength and ductile–brittle transition point of the blends. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers  相似文献   

7.
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  相似文献   

8.
采用机械共混法制备了聚氯乙烯/氯化聚乙烯/苯乙烯-乙烯-丁二烯-苯乙烯共聚物(PVC/CPE/SEBS-g-MAH)三元共混物,利用扫描电镜、差示扫描量热仪和力学性能测试等方法研究了共混物的结构和性能,探讨了SEBS-g-MAH对共混物力学性能的影响。结果表明:CPE用量为3份、SEBS-g-MAH用量为6份时,CPE与SEBS-g-MAH协同增韧效果最显著,此时共混物的相容性最佳,综合力学性能较好。  相似文献   

9.
The electrical and damping behaviors of chlorinated polyethylene (CPE)/2,2′‐methylene‐bis‐(4‐methyl‐6‐cyclohexylphenol) (ZKF)/vapor‐grown carbon fiber (VGCF) have been investigated. CPE/ZKF/VGCF systems exhibit typical percolation characteristics of filled conductive polymer composites. For CPE/ZKF/VGCF composites, dynamic mechanical analysis (DMA) shows that, at the glass transition temperature (Tg) of CPE/ZKF system, the values of loss factor increase with the increasing VGCF content. Within the temperature range of 60–75°C, the values of loss factor for CPE/ZKF/VGCF samples are higher than that of CPE/ZKF and present a peak at 16 vol% VGCF content. This implies that the piezo‐damping effect is directly related to the conductive network formation in the composites, and the piezo‐damping effect can be regulated by regulating the VGCF content. Therefore, the composite of CPE/ZKF/VGCF is a good damping material with a high and broad loss factor that can be regulated according to practical applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3181–3185, 2006  相似文献   

10.
《国际聚合物材料杂志》2012,61(3-4):149-158
Abstract

Polylauryllactam was used to improve the impact strength of polyvinylchloride (PVC)/chlorinated polyethylene (CPE) blends without sacrificing their tensile properties. The enhancement of the impact strength increased with the increase of the CPE content in the PVC/CPE blends due to the formation of intermolecular hydrogen bonds among PVC, polylauryllactam and CPE macromolecules. A doubled impact strength of the PVC/CPE blend with 20 weight percent of CPE was obtained after the addition of 1.5 phr polylauryllactam. The PVC/CPE blends with polylauryllactam have a better dimensional stability compared with the PVC/CPE blends without the additive, according to their viscoelastic characteristics. Polylauryllactam shortened the processing time to reach a minimum melt viscosity in the processing of the PVC/CPE blends.  相似文献   

11.
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   

12.
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.  相似文献   

13.
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  相似文献   

14.
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 Tgs 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  相似文献   

15.
The toughness of impact‐modified poly(vinyl chloride) (PVC) compounds was examined by using a modified Charpy test. Increasing impact speed resulted in a quasi‐brittle to ductile transition in all PVC compounds. In the quasi‐brittle region, a PVC of 56,000 Mw fractured through a craze‐like damage zone that could be described by a modified Dugdale model. Furthermore, the same molecular‐weight PVC modified with either 10 pph (parts per hundred parts by weight) of chlorinated polyethylene (CPE) or 10 pph of methylmethacrylate‐butadiene‐styrene (MBS) impact modifier also conformed to the Dugdale model with the craze‐like damage zone. The CPE effectively improved the impact performance of PVC by shifting the quasi‐brittle to ductile transition to a higher loading rate. Compared to CPE, MBS was a better impact modifier, and its use resulted in a higher quasi‐brittle to ductile transition loading rate in the same PVC matrix. Fracture initiation toughness of all the materials was described by the Hayes‐Williams modification of the Dugdale model. The intrinsic brittle fracture energy obtained by extrapolation to zero craze length was determined only by the PVC matrix and was independent of the impact modifier. However, the kinetics of craze growth, and hence the response to rapid loading, depended on the impact modifier. Increasing the molecular weight of the PVC resin resulted in a more complex damage zone that was not amendable to the Dugdale analysis. J. Vinyl Addit. Technol. 10:11–16, 2004. © 2004 Society of Plastics Engineers.  相似文献   

16.
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  相似文献   

17.
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  相似文献   

18.
The ultraviolet radiation aging behaviors of PVC/CaCO3 and PVC/CaCO3/macromolecular modifier composites were studied through whiteness measurement, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, scanning electron microscopy, and mechanical properties test. It was found that nano‐CaCO3 particles used as ultraviolet light screening agents could significantly enhance the antiaging properties of PVC materials. Due to the macromolecular modifier coated on nano‐CaCO3 particles, the compatibility of nano‐CaCO3 and PVC matrix was improved, resulting in uniform dispersion of nano‐CaCO3 in PVC matrix. Therefore, the PVC/CaCO3/MP composite exhibited better antiaging properties than PVC/CaCO3 composite. After 12 h of ultraviolet irradiation, the tensile strength retention, elongation at break retention, and impact strength retention of PVC/CaCO3/MP composite were 79.5%, 74.5%, and 75.3%, which were much higher than that of neat PVC and PVC/CaCO3 composite. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

19.
The permeability P, diffusivity D, and activation energy for diffusion, ED, of He, O2, N2, and CO2 were determined for blends of PVC/chlorinated polyethylene (CPE), where the chlorine content of the CPE components varied: 36 wt-% for CPE-1, 42 wt-% for CPE-2, and 48 wt-% for CPE-3. The difference in thermal expansion coefficients Δα above and below the glass transition temperature Tg of the polymers and the fractional free volume Vg of the polymers at their Tg were determined. Density and crystallinity measurements for the blends were also carried out as in the earlier work (Shur and Rånby, J. Appl. Polym. Sci., 19 , 1337 (1975)). Dynamic mechanical measurements of the blends were made using a torsion pendulum at about 1 Hz. P and D decreased, but ED increased with increasing CI content of CPE in the blends. P and D for the blends showed no additivity. The permeability indicated phase inversion for blend compositions at about 10% of CPE-1 and CPD-2 by weight. The experimental and the calculated densities were largely the same for PVC/CPE-1 blends; but for PVC/CPE-2 and PVC/CPE-3 blends, the experimental values were higher than the calculated ones. The Δα and Vg values for PVC and the three CPE samples decreased with increasing CI content in the polymers. Dynamic mechanical measurements indicate that PVC/CPE-1 and PVC/CPE-2 blends form largely incompatible blends, while PVC/CPE-3 blends are compatible to some extent. There is some weak interaction between PVC and CPE-3 giving a low level of compatibility. The solubility of gases obtained from time-lag measurements of diffusion for 50/50 blends decreased for He, O2, and N2, but increased for CO2 with increasing Cl content in CPE. The solubility of He, O2 and N2 shows a positive correlation with the Lennard-Jones force constant ?/k. However, a deviation from the linear relation between ?/k and In S was observed for CO2 and the deviation became larger with increasing Cl content in CPE. The abnormally high solubility of CO2 is probably due to the high polarizability of this gas. The heat of solution ΔHs indicates that for He the sorption process may be a molecular slip process (endothermic), but for other gases the sorption may proceed by a dissolution process (exothermic). There is a large difference between the calculated solubility for the blends assuming incompatibility and the experimental values from time-lag measurements. This may partly be due to the uncertainty of sorption values obtained from the time-lag method and/or partly to changes of sorption modes by interaction between PVC and CPE in the blends. The resulting transport behavior of the blends is discussed on the basis of the free volume concept and of phase–phase interaction in the blends.  相似文献   

20.
The effects of styrene-co-acrylonitrile resin (AS) on the mechanical properties, morphology, and plasticizing and rheological behaviors of poly(vinyl chloride)/chlorinated polyethylene(PVC/CPE) blends are studied. The results show that the impact strength and the tensile strength are all increased and the plasticizing and rheological behaviors are also improved when a certain amount of AS is added into PVC/CPE blends, which are different in characteristics and regularity from plastics toughened with elastomers. It is blends of brittle—ductile transition regions (i.e., PVC/CPE = 100/10, 100/15) that can obviously be toughened by AS. The analysis of the morphological structure shows that AS promotes the formation of a CPE network that embeds the primary particles of PVC. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1455–1460, 1997  相似文献   

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