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1.
Nanocomposite films were prepared through the blending of polyimide (PI) with octaphenyl silsesquioxane (OPS) and an amino‐functionalized analogue, octaaminophenyl silsesquioxane (OAPS), with a solution‐casting method. Although the PI–OPS composites showed visible phase separation at 5 wt %, the PI–OAPS composites were transparent with visible phase separation occurring only at 50 wt % OAPS. The interfacial interactions and homogeneity of the composites were characterized with scanning electron microscopy (SEM) and dynamic mechanical analysis. SEM analysis showed a uniform fracture surface for OAPS composites at concentrations up to 20 wt %. Interestingly, OAPS‐rich particles with sizes of less than 1 μm were formed within the PI matrix for the 50 wt % composite. The PI–OAPS composites showed higher glass‐transition temperatures (Tg's) than the pure PI. The PI–OPS composites showed a Tg lower than that of the pure PI, and this suggested poor interfacial interactions. The slightly enhanced thermal stability of PI–OAPS composites (up to 20 wt %) was attributed to the inherent thermal stability of OAPS at higher temperatures. There were small increases in the modulus and strength for the composites with respect to the base polymer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

2.
Carbon nanotubes (CNTs) and graphene were separately incorporated into the cross‐linked network of styrene–divinylbenzene composites via in situ suspension polymerization. The prepared copolymers were first chloromethylated and then aminated with trimethylamine to obtain ion exchange resins (IERs). The CNTs‐based and graphene‐based composites exhibited good dispersion throughout the polymer matrix with strong interaction within the network. Remarkable enhancement in antiswelling properties and thermal stabilities confirmed that graphene showed better compatibility and stronger interfacial adhesion than CNTs. The structural and thermal properties of the CNTs‐based and graphene‐based IERs were also significantly improved even at low loadings of 0.4 wt % compared with those when no CNTs and graphene were added. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41234.  相似文献   

3.
Novel phosphorus‐containing copolyester nanocomposites were synthesized by in situ polymerization with 2‐carboxyethyl(phenylphosphinic) acid (CEPPA) and nano‐ZnCO3. The flame retardancy and static and dynamic mechanical properties of poly(ethylene terephthalate) (PET)/nano‐ZnCO3 composites and phosphorus‐containing copolyester/nano‐ZnCO3 composites were evaluated with limiting oxygen index measurements, vertical burning testing (UL‐94), a universal tensile machine, and a dynamic mechanical analysis thermal analyzer. The phosphorus‐containing copolyester nanocomposites had higher limiting oxygen indices (ca. 32%) and a V0 rating according to the UL‐94 test; this indicated that nano‐ZnCO3 and CEPPA greatly improved the flame retardancy of PET. The static mechanical test results showed that the breaking strength, modulus, and yield stress of the composites tended to increase with increasing nano‐ZnCO3 content; when 3 wt % nano‐ZnCO3 was added to PET and the phosphorus‐containing copolyester, the breaking strength of the composites was higher than that of pure PET. Dynamic mechanical analysis indicated that the dynamic storage modulus and loss modulus of the PET composites increased markedly in comparison with those of pure PET. However, the glass‐transition temperatures associated with the peaks of the storage modulus, mechanical loss factor, and loss modulus significantly decreased with the addition of ZnCO3 and CEPPA. The morphologies of the composites were also investigated with scanning electron microscopy, which revealed that nano‐ZnCO3 was dispersed homogeneously in the PET and copolyester matrix without the formation of large aggregates. In addition, the interfacial adhesion of nano‐ZnCO3 and the matrix was perfect, and this might have significantly affected the mechanical properties of the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

4.
Poly(ethylene terephthalate) (PET) containing epoxy‐functionalized polyhedral oligomeric silsesquioxane (POSS) was prepared by melt‐mixing and in situ polymerization methods. The melt‐mixed composite showed phase separation while the in situ polymerized composite did not, based on SEM characterization. During melt mixing, the reaction between the epoxy groups of POSS and hydroxyl groups of PET occurred, based on DSC results. DSC results on the in situ polymerization product showed formation of a lower‐melting component compared with PET. The tensile strength and modulus of the melt‐mixed composite fiber decreased compared with those properties of PET, whereas those of the in situ polymerized composite showed slightly higher values than PET despite the relatively small amounts (1 wt%) of POSS used. Dynamic mechanical analysis results showed an increase in storage modulus for the in situ polymerized composite of POSS and PET compared with PET over the temperature range of 40 °C to 140 °C. Copyright © 2004 Society of Chemical Industry  相似文献   

5.
Poly(ethylene terephthalate) (PET) chips were coated by trisilanolphenyl–polyhedral oligomeric silsesquioxane (T‐POSS) and hexakis (para‐allyloxyphenoxy) cyclotriphosphazene (PACP) using the predispersed solution method, and PET/PACP/T‐POSS hybrids were further prepared by the melt‐blending method. The influence of T‐POSS on the rheological, thermal, and mechanical properties and flame retardancy of PET/PACP composites were discussed. The results suggest that T‐POSS was homogeneously dispersed in the PET matrix, which reduced the negative effects on polymer rheology and mechanical properties. For the PET/4%PACP/1%T‐POSS sample, the tensile strength at break and Tg increased from 29.67 MPa and 81.7 °C (PET/5%PACP) to 34.8 MPa and 85.8 °C, respectively, but the sample also self‐extinguished within 2 s, and the heat release capacity was reduced by 27.9% in comparison with that of neat PET.© 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45912.  相似文献   

6.
Homogeneous dispersion and strong filler–matrix interfacial interactions were vital factors for graphene for enhancing the properties of polymer composites. To improve the dispersion of graphene in the polymer matrix and enhance the interfacial interactions, graphene oxide (GO), as an important precursor of graphene, was functionalized with amine‐terminated poly(ethylene glycol) (PEG–NH2) to prepare GO–poly(ethylene glycol) (PEG). Then, GO–PEG was further reduced to prepare modified reduced graphene oxide (rGO)–PEG with N2H4·H2O. The success of the modification was confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis, and Raman spectroscopy. Different loadings of rGO–PEG were introduced into polyimide (PI) to produce composites via in situ polymerization and a thermal reduction process. The modification of PEG–NH2 on the surface of rGO inhibited its reaggregation and improved the filler–matrix interfacial interactions. The properties of the composites were enhanced by the incorporation of rGO–PEG. With the addition of 1.0 wt % rGO–PEG, the tensile strength of PI increased by 81.5%, and the electrical conductivity increased by eight orders of magnitude. This significant improvement was attributed to the homogeneous dispersion of rGO–PEG and its strong filler–matrix interfacial interactions. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45119.  相似文献   

7.
Biodegradable organic–inorganic hybrids based on poly(?‐caprolactone) (PCL) and polyhedral oligomeric silsesquioxane (POSS) with 5.3–21.3 wt % POSS were synthesized via ring‐opening polymerization (ROP). Chemical structures of the polymers were characterized by proton nuclear magnetic resonance (1H NMR), fourier transform infrared spectroscopy (FTIR), and gel permeation chromatography (GPC). X‐ray diffraction (XRD) analysis illustrated that both POSS and PCL segment in POSS/PCL hybrids could crystallize and form two well‐separated crystalline phases except in the one with low content of POSS (5.3 wt %). Melting behavior and non‐isothermal crystallization kinetics of POSS/PCL hybrids were studied by differential scanning calorimeter (DSC). The results indicated that the POSS segment suppressed crystallization of the PCL segment to some extent. Polarizing optical microscope (POM) images showed that POSS/PCL hybrids with the highest POSS loading (21.3 wt %) possessed “snowflake” shape crystals whereas the ones with relatively low POSS loading exhibited classic spherulites. Thermogravimetry (TG) measurement revealed that thermal degradation of POSS/PCL hybrids proceeded by four‐step while PCL homopolymers degraded by a single step. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44113.  相似文献   

8.
To study the effect of a surfactant on the properties of polyaniline (PANI)/metal oxide composites, PANI/lead titanate (PbTiO3) composites were synthesized with different weight percentages (10, 20, 30, 40, and 50 wt %) of PbTiO3 in both the absence and presence of dodecylbenzenesulfonic acid (DBSA) by the polymerization of aniline with ammonium persulfate as an initiator. The structural characteristics and stability, surface characteristics, and electric properties of PANI/PbTiO3 and PANI–DBSA/PbTiO3 were studied and compared. The interfacial interactions and thermal stability of these composites were characterized with X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and thermogravimetry techniques. The results indicate significant changes in the physicochemical properties of the composites with the incorporation of DBSA. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

9.
An array of polyhedral oligomeric silsesquioxane (POSS) compounds, including metal, methacrylate, and amine functional POSS, and POSS copolymers were incorporated into aromatic and aliphatic dental resins. Heptaphenyl‐propylamine POSS and methacrylate derivatives were synthesized by corner‐capping and Michael addition reactions, respectively. The POSS compounds were tested for solubility in commercial resins at concentrations of 1, 5, 10, and 15 wt %, followed by UV polymerization of all soluble combinations. The POSS compounds generally increased modulus and had an unpredictable effect on Tg. The modulus of the aliphatic resin increased 83% by incorporation of 15 wt % aluminum‐phenyl POSS, while aromatic resins saw a maximum modulus improvement of 18% at 30°C and 72% at 160°C by incorporating 1 wt % of heptaphenyl‐methacrylate POSS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2856–2862, 2006  相似文献   

10.
Polyhedral oligomeric silsesquioxanes (POSSs), with inorganic cores, offer excellent mechanical properties and have external organic substituents. On the basis of their hybrid organic?inorganic characteristics, which allow for a tunable reaction or miscibility with various materials, in this study, we introduced a bifunctional POSS as a novel rigid compatibilizer for polypropylene (PP)–titanium dioxide (TiO2) composites and evaluated its compatibilizing effects at different processing temperatures. The results show that the attached hydroxyl and isobutyl groups allowed for the reaction with TiO2 and miscibility with the PP matrix. However, at lower processing temperatures, POSS existed in the form of solid particles, and its interfacial absorption was too poor for sufficient coverage of the TiO2 surface; this resulted in a weak compatibilization effect on the PP–TiO2 composite. When the processing temperature was increased to 240 °C, the solid POSS turned into a liquid and thus had strong mobility; this was favorable for the diffusion of TiO2 onto the surface and the construction of a strong interfacial phase. Because the rigid characteristic of POSS made a positive contribution to the performances of the composites, the PP–TiO2 composites prepared at higher processing temperatures exhibited better mechanical properties, with the maximum increases occurring in the compositions containing 5 wt % POSS. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44766  相似文献   

11.
The organic–inorganic hybrid nanocomposites from high‐impact polystyrene/octavinyl polyhedral oligomeric silsesquioxane (HIPS/POSS) containing various percentages of POSS were prepared by free radical polymerization and characterized by Fourier transform infrared spectroscopy (FTIR), 1H‐NMR, thermal gravity analysis (TGA), X‐ray diffraction (XRD), and transmission electron microscopy (TEM). The octavinyl POSS has formed covalent bond connected PS‐POSS hybrid with polystyrene. POSS can well disperse in the composites at the composition of 0.5 and 1 wt%. The mechanical properties and thermostability of HIPS/POSS nanocomposites were significantly improved. The tensile strength, the izod impact strength, and the elongation at break of the nanocomposite containing 1 wt% of POSS was increased, respectively, by 15.73%, 75.62%, and 72.71% in comparison with pristine HIPS. The thermal decomposition temperature of HIPS/POSS (1 wt% of POSS) was 33°C higher than that of pristine HIPS. The HIPS/POSS nanocomposites showed great potential for applications in many fields, such as electric appliance and automotive trim. POLYM. COMPOS. 37:1049–1055, 2016. © 2014 Society of Plastics Engineers  相似文献   

12.
A series of glycerin‐crosslinked polyurethane (XPU)‐clay nanocomposites were prepared by in situ polymerization followed by solution casting and thermal treatment. The weight percent (wt %) of clay in the nanocomposites was varied between 0.25 and 10. The structural, rheological and dynamic mechanical properties of the nanocomposites were investigated. X‐ray diffraction (XRD) analysis showed that well dispersed clay platelets were formed in nanocomposites containing up to 1 wt % of clay. Scanning electron microscopy (SEM) showed that poorly dispersed and non‐exfoliated clays were present in composites containing >2 wt % of clay and resulted in phase‐separated disparities within the matrix. Rheological studies demonstrated that processability of polyurethane was significantly improved after clay addition such that solution viscosity decreased by between 76 and 90%. Furthermore, the presence of chemical and physical crosslink networks within the matrix resulted in a remarkable enhancement in the rubbery plateau storage modulus. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43346.  相似文献   

13.
Poly(vinyl chloride)/chlorinated polyethylene (PVC/CPE)/methylacryloylpropyl‐containing polyhedral oligomeric silsesquioxane (MAP–POSS) nanocomposites are prepared. The plastic behavior and dynamic rheological behavior of PVC/CPE/MAP–POSS are investigated. The influences of composition on dynamic storage modulus G′, loss modulus G″, and complex viscosity η* of PVC/CPE/MAP–POSS melts are discussed. The dynamic mechanical properties, mechanical properties, and morphology are determined. The results show that both plastic time and balance torque of the nanocomposites decrease, but the G′, G″, and η* all increase with increasing MAP–POSS content. The maximum value of the dynamic mechanical loss tan δ decreases and elasticity increases when MAP–POSS is added. The impact strength of the nanocomposites increases with increasing MAP–POSS content and has the best value at 10% content of MAP–POSS, which is 5.38 kJ/m2 higher than that of the blend without MAP–POSS. The MAP–POSS can be used as an efficient process aid and impact aid for the PVC/CPE blend. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

14.
Two types of nanocomposites have been fabricated by a ball‐milling technique. The first type consists of untreated titanium dioxide (TiO2) incorporated into low‐density polyethylene (LDPE). For the second one, TiO2 filler chemically treated with trisilanol phenyl–polyhedral oligomeric silsesquioxane (TP–POSS) as compatibilizing agent was ball‐milled with LDPE. All specimens were tested by microstructure analysis and thermal, dielectric characterization techniques. Microstructure analysis by atomic force microscopy and scanning electron microscopy show clearly an increased dispersion in presence of POSS. Scanning electron microscopy even shows the formation of a particular structure due possibly to interactions between functionalization. It was observed that the modification of the surface of TiO2 by the POSS decreased the dielectric loss. All nanocomposites containing treated TiO2 revealed an improvement in thermal conductivity, with the most distinct value of 19% in case of LDPE containing 5 wt % treated TiO2. The incorporation of TiO2 fillers seems to reduce the dielectric breakdown strength of the nanocomposites. However, nanocomposites containing 3 and 5 wt % treated TiO2 have exhibited a slightly enhancement in dielectric breakdown strength up to 5%. The improvement in surface resistance to partial discharge was found in all nanocomposites specimens, especially for both types of composite containing 7 wt % untreated and treated TiO2. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46095.  相似文献   

15.
The homogeneous dispersion and strong interfacial interactions of carbon nanomaterials are vital factors on enhancing the properties of polymer composites. Two‐dimensional reduced graphene oxide (rGO) and one‐dimensional carbon nanotubes (CNTs) were first grafted by 4,4′‐oxydianiline (ODA). The successful grafting of ODA onto the rGO and CNTs were confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis, and X‐ray photoelectron spectroscopy. The hybrid carbon nanomaterials of the functionalized CNTs and rGO with different ratios were prepared via a solution‐mixing method, and their dispersion state was investigated. The hybrid carbon nanomaterials with good stability were introduced to polyimide (PI) via in situ polymerization. The morphology and properties of the polymer composites were studied. The results show that much better mechanical and electrical properties of the composites could be achieved in comparison with those of the neat PI. An improvement of 100.7% on the tensile strength and eight orders for the electrical conductivity were achieved at only a 1.0 wt % hybrid content. A significant enhancement effect was attributed to the homogeneous dispersion of the filler, filler–matrix strong interfacial interactions, and unique structure of the hybrid carbon nanomaterials in the composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44575.  相似文献   

16.
Composites of polydimethylsiloxane (PDMS) rubber modified by three kinds of polyhedral oligomeric silsesquioxanes (POSSs) as well as fumed silica were prepared through solution blending and then open two‐roll mill blending with curing agent. Subsequently, the influences of POSS on mechanical and thermal properties of the resulting composites were investigated in detail. The addition of POSS significantly enhanced the tensile strength and elongation at break of the composite but lowered the tensile modulus, which could be ascribed to the interruption of silica–silica and silica–PDMS interactions. Octamethylsilsesquioxane (OMS)/silica/PDMS and octaphenylsilsesquioxane (OPS)/silica/PDMS composites did not show desirable mechanical and thermal properties. Nevertheless, heptaphenylvinylsilsesquioxane (VPS)/silica/PDMS composite with 5 wt % VPS exhibited enhanced glass transition temperature (Tg), mechanical properties, and thermal stability. Further studies revealed that more VPS unfavorably affected properties of the composite. Scanning electron microscope and X‐ray diffraction demonstrated that owing to the grafting reaction, 5 wt % VPS in the rubber matrix could form microcrystal domains the most effectively. Thus, the improved mechanical properties and thermal stability just resulted from the the formation of microcrystal domains and the increase in stiffness of PDMS chains because of the graft of VPS onto PDMS. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42173.  相似文献   

17.
Polyhedral oligomeric silsesquioxane (POSS)/polypropylene (PP) composites in the presence of β-nucleating agent (β-NAs) were prepared by melt-blending, and the interfacial interaction and crystallisation behaviour were investigated. The experimental results indicated that strong hydrogen bonding interactions were generated between amino groups of β-NAs and silicon hydroxyl groups attached to POSS, allowing the absorption/anchoring of the former on the surface of latter. Compared to POSS, β-NAs exhibited higher nucleation effect on PP, as evidenced by an increment of the crystallisation temperature by 7°C in the presence of β-NAs. As a result, the absorbed β-NAs on the surface of POSS not only improved the interfacial interaction between POSS and polymer matrix using interfacial crystallisation but also promoted the formation of β-crystals with toughening effect, which is very important to prepare excellent-performance PP/POSS composite.  相似文献   

18.
The main objective of this research was to synthesize a new compatibilisant agent (PVC‐g‐MA), which was grafted from the maleic anhydride on the PVC chains. The presence of maleic anhydride grafting on PVC was made evident by infrared analysis. PVC‐g‐MA was used like compatibilisant to solve the problem of the incompatibility between the hydrophobic polymeric matrix (PVC) and hydrophilic fiber (alfa). Composites samples were prepared with different alfa fiber loading (10, 20, and 30 wt %) and incorporating PVC‐g‐MA (1, 3, and 5 wt %) or PP‐g‐MA (3 wt %). The tensile properties, the thermal stability and the morphology of the composites were investigated. The result indicated that the PVC‐g‐MA increased the interfacial adhesion between the fibers and the polymer matrix and this effect was better than that obtained for the maleated‐polypropylene‐coupled composites. Microstructure analysis of the fractured surfaces of MAPP modified composites confirmed improved interfacial bonding. The addition of alfa and PVC‐g‐MA increased the thermal stability of the composites. The temperature of degradation of the polymer matrix increased about 16°C in comparison to the noncoupled composite, indicating that PVC‐g‐MA improved the thermal stability of the polymer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

19.
In the present work, different compatibilizers, namely polyethylene‐graft‐maleic anhydride (PE‐g‐MA), polypropylene‐graft‐maleic anhydride (PP‐g‐MA), and polystyrene‐block‐poly(ethylene‐ran‐butylene)‐block‐polystyrene‐graft‐maleic anhydride (SEBS‐g‐MA) were used on green composites derived from biobased polyethylene and peanut shell (PNS) flour to improve particle–polymer interaction. Composites of high‐density polyethylene/peanut shell powder (HDPE/PNS) with 10 wt % PNS flour were compatibilized with 3 wt % of the abovementioned compatibilizers. As per the results, PP‐g‐MA copolymer lead to best optimized properties as evidenced by mechanical characterization. In addition, best particle–matrix interface interactions with PP‐g‐MA were observed by scanning electron microscopy (SEM). Subsequently HDPE/PNS composites with varying PNS flour content in the 5–30 wt % range with PP‐g‐MA compatibilizer were obtained by melt extrusion and compounding followed by injection molding and were characterized by mechanical, thermal, and morphological techniques. The results showed that PNS powder, leads to an increase in mechanical resistant properties (mainly, flexural modulus, and strength) while a decrease in mechanical ductile properties, that is, elongation at break and impact absorbed energy is observed with increasing PNS flour content. Furthermore, PNS flour provides an increase in thermal stability due to the natural antioxidant properties of PNS. In particular, composites containing 30 wt % PNS powder present a flexural strength 24% and a flexural modulus 72% higher than the unfilled polyethylene and the thermo‐oxidative onset degradation temperature is increased from 232 °C up to 254 °C thus indicating a marked thermal stabilization effect. Resultant composites can show a great deal of potential as base materials for wood plastic composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43940.  相似文献   

20.
Cellulose–graphene oxide (GO) aerogel composites were successfully prepared from cellulose and GO dispersed in N‐methyl morpholine‐N‐oxide monohydrate, a nontoxic and environmentally friendly solvent, after a freeze‐drying process. Because of the strong interactions between the numerous oxygen‐containing groups located on the surface of GO and the functional groups of the cellulose molecules, the GO monolayers were well dispersed in the three‐dimensional porous structure of the cellulose aerogels. With the addition of 10 wt % GO, the swelling ratios and water contents of the composite cellulose–GO aerogels increased from 468 to 706% and from 82.4% to 87.6%, respectively. The corresponding maximum decomposition temperatures also increased from 335 to 353 °C with increasing GO content from 0 to 10%; this indicated that the thermal stability of the cellulose–GO aerogels was enhanced. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46152.  相似文献   

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