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In this work, a hybrid coating (TSMA) was produced using tetraethyl orthosilicate (TEOS)/KH550/Styrene maleic anhydride copolymer (SMA) as raw materials. The coating was afterwards applied to modify recycled coir (r-coir) fibers via dip-coating. R-coir fibers reinforced ABS composites were then prepared and the reinforcing effect of fibers on the composite structure was investigated, as well. The r-coir fibers coated with TSMA were hydrolyzed in air for 3 days. The SiO2 particles produced by sol-gel reaction of TEOS were used to connect KH550 and SMA to the surface of the fibers and form an organic-inorganic ‘armor’ structure. The successful surface modification of the r-coir fibers was proved via FTIR spectroscopic study and the improvement of their decomposition temperature was evidenced by TGA. Furthermore, the homogeneous dispersion of TSMA on the surface of r-coir fibers was observed via SEM. In addition, the tensile strength of single fibers was found to increase by 36.1%. According to the results, TSMA can be successfully homogenized on the fiber surface, enabling one to repair the damaged areas and improve the tensile strength of single fibers. Besides, good compatibility between r-coir fibers and ABS was revealed by contact angle measurements. Furthermore, the bending strength and elastic modulus of TSMA-modified r-coir fibers/ABS composites were improved by 6% and 27%, respectively. Therefore, the method of plant fiber modification proposed in present work provides a reliable way for effective reuse of r-coir fibers.

Polyvinyl alcohol (PVA)/carboxyl methyl cellulose sodium (CMC)/Na2CO3 composite films with different contents of Na2CO3 were prepared by blending and solution-casting. The effect of Na2CO3 on the microstructure of PVA/CMC composite film was analyzed by Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and atomic force microscopy (AFM). Its macroscopic properties were analyzed by water sorption, solubility, and dielectric constant tests. The results show that the microstructure of PVA/CMC/Na2CO3 composite films was different from that of PVA and PVA/CMC composite films. In addition, compared to PVA and PVA/CMC composite films, the water sorption of PVA/CMC/Na2CO3 composite films relatively increased, the solubility in water significantly decreased, and the dielectric properties significantly improved. All these results indicate that the hydrogen bonding interaction between PVA and CMC increased and the crystallinity of PVA decreased after the addition of Na2CO3. This was also a direct factor leading to increased water sorption, decreased solubility, and enhanced dielectric properties. The reaction mechanism of PVA, CMC, and Na2CO3 is proposed to further evaluate the effect of Na2CO3 on the microstructure and macroscopic properties of PVA/CMC/Na2CO3 composite films.

In this article, polytetrafluoroethylene (PTFE) microporous membranes with excellent tensile strength and good wear durability were successfully fabricated by the addition of nano-alumina (Al2O3). The friction and mechanical behavior of PTFE microporous membranes with different nano-Al2O3 contents were investigated by Martindale abrasion tester, dynamic mechanical analysis, and universal testing machine. Scanning electron microscopy was applied to analyze the surface, longitudinal section, and worn surface of the microporous membranes. Results demonstrated that nano-Al2O3 particles were dispersed into the “node” structures of PTFE microporous membranes and acted as the skeleton, leading to the increasing of the tensile strength remarkably. The wear rate reduced significantly with the addition of nano-Al2O3 and was affected by nano-Al2O3 content. Additionally, the wear mechanism of the microporous membranes was also discussed based on the study results.

Acrylonitrile–butadiene rubber (NBR)/anhydrous copper sulfate (CuSO4) composites were prepared by coordination cross-linking. CuSO4 particles of different sizes are obtained by ball milling in acetone. During heat pressing at 190 °C, a strong cross-linking reaction occurred, which resulted from coordination between cupric ions and nitrile groups. Results showed that the mean size of CuSO4 particles decreased from 7.1 to 0.4 μm after ball milling. Accordingly, the number of coordination cross-linking points increased remarkably, which resulted in an increase in the glass transition temperature and equilibrium torque of the composites. Two models were employed to discuss the cross-link density and demonstrated that both CuSO4 particles and cupric ions contributed to the improvement of cross-linking points. It was noteworthy that this composite exhibited high strength and toughness, with 73.5 MPa tensile strength and 423.7% elongation at break. Moreover, a unique stretching phenomenon, including the features of both rubber and plastic, was observed and explained in detail.

In this paper, ‘one-step’ molding process was used to prepare r-PET fiber-reinforced PE composites. Effects of compatibilizer HY-3308 and fiber content on interfacial properties, thermal properties, mechanical properties, and the fiber dispersion of the composites were studied. FTIR, contact angle test, and SEM results indicated that the compatibilizer improved the interfacial combination between the PET fiber and PE matrix. DMA, DSC, mechanical properties, density, and SEM results indicated that with an increase of HY-3308 content, bonding between the fiber and matrix became tight; the phase interface became blurred, and the mechanical properties were gradually improved. Such a ‘one-step method’ preparation of the r-PET fiber-reinforced PE composites is simple, which is beneficial for the industrialization of recycling processes for r-PET fiber.

The recycling and self-healing functions of commercial rubber are of great significance in the field of sustainable materials. So far, manufacturing such rubber with excellent strength and toughness was still a huge challenge. Herein, the multi-coordination crosslink networks were designed to achieve this goal. First, the nitrile-butadiene rubber (NBR) was modified through 3,6-di(2-pyridyl)-1,2,4,5-tetrazine (DPT) click reaction to introduce the second ligand group. Next, the blend of modified NBR and metal salt (including ZnCl2 and CoCl2) was hot-pressed to form the metal-nitrile and metal-pyridine (nitrogen-containing heterocyclic groups) coordination bonds. The designed composite had ultra-high mechanical strength and toughness at the same time. Compared with the NBR/ZnCl2 composite, the tensile strength of NBR-DPT4-Zn10 composite with multi- coordination bonds was improved by 7.5-fold (from 5.5 MPa to 46.82 MPa), and the corresponding fracture energy was improved by 142% (from 26.2 MJ m−3 to 63.5 MJ m−3). At the same time, the high recyclable and heat-healing efficiency were obtained. These achievements are expected to develop commercial rubber’s recyclability and high mechanical properties.

Damping rubber, which is a blend of chlorinated isobutylene isoprene rubber (CIIR) and micromolecule resins (petroleum resins or rosin resins), was impregnated onto Wrap Knitted Spacer Fabric (WKSF) through solution method in order to produce damping rubber/WKSF composites. CIIR-grafted–(maleic anhydride) (abbreviated as CIIR-g-MAH) was synthesized and used as a novel compatibilizer for damping rubber/WKSF composites. The loss tangent factor (tan δ) values decreased and the tan δ peak moved to a lower temperature after WKSF was added. The tensile strength of the damping rubber was improved significantly with the skeleton structure of WKSF. The addition of CIIR-g-MAH increased the tensile strength further. Interfacial shear strength showed strong interactive interface between the matrix and the polyethylene terephthalate (PET) fiber of WKSF after the addition of CIIR-g-MAH. Scanning electron microscopy showed the morphology of the fracture surface and the interfacial compatibilization mechanism was investigated. POLYM. COMPOS., 2017. © 2017 Society of Plastics Engineers

Crosslinked ultra-high-molecular-weight polyethylene (UHMWPE) with excellent shape memory properties was prepared from the silane-grafted UHMWPE mixed with water-carrying agent by compression molding. The alkoxysilane hydrolyzation and condensation reaction of the silane-grafted UHMWPE allowed for the generation of Si–O–Si chemical crosslinking points between the polymeric chains. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy results confirmed that silane has been grafted on UHMWPE chains successfully. The resulting crosslinked products were characterized using dynamic mechanical analysis, gel measurement, impact test, tensile test, thermogravimetric analysis and shape memory bending test to obtain insight into the relationship between the structure and the properties. By controlling the content of water-carrying agent, the average molecular weights between crosslinking points (M c) reduced from 29,530 to 9540 g/mol. The decomposition temperature (T d) value increases from 467.7 for virgin resin to 491.5 °C for the crosslinked product with 91.64% gel ratio. The crosslinked materials showed much better shape memory effect than pure UHMWPE; the shape recovery ratio (R ν ) value of silane-induced crosslinked UHMWPE with 1.0 phr water-carrying agent reaches above 98.0% under multiple deformation recovery cycle. Therefore, the silane-induced crosslinking UHMWPE has a great potential in the shape memory material applications.

Acrylonitrile–butadiene–styrene (ABS) composites filled with anhydrous copper sulfate (CuSO4) particles were prepared by planetary ball mill. The ball milling process can provide CuSO4 particles of small sizes for homogeneous particle distribution in a matrix. To directly enhance the interaction between the two ingredients, a coordination reaction was generated by heat press at 180 °C. Fourier transform infrared, electron spin resonance, Ultraviolet–visible, and X-ray photoelectron spectroscopy were employed to investigate the coordination reaction. The results showed that a coordination reaction happened between nitrile groups (–CN) of ABS and copper ions (Cu2+) of CuSO4. The loss factor of dynamic mechanical analysis indicated the decrease of intermolecular friction due to a strong interaction between the matrix and the particles. The homogeneously dispersed, micro-sized CuSO4 particles were observed by scanning electron microscope. The interface was indistinguishable under the microscope indicating a well-bonded surface and good compatibility. In addition, dissolution behavior showed that the solvent resistance of the composites was significantly improved.

Surface modification fundamentally influences the morphology of polyethylene terephthalate (PET) fibers produced from abandoned polyester textiles and improve the compatibility between the fiber and the matrix. In this study, PET fiber was modified through solution dip-coating using a novel synthesized tetraethyl orthosilicate (TEOS)/KH550/ polypropylene (PP)-g-MAH (MPP) hybrid (TMPP). The PET fiber with TMPP modifier was exposed to the air. SiO2 particles would be hydrolyzed from TEOS and become the crystalline cores of MPP. Then, the membrane formed by MPP, SiO2 and KH550 covered the surface of the PET fiber. TMPP powder was investigated and characterized by fourier transform infrared spectroscopy, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). TMPP-modified PET fiber was researched by X-ray diffraction and SEM. Furthermore, tensile strength of single fiber was also tested. PET fiber/PP composites were studied through dynamic mechanical analysis and SEM. Flexural properties of composites were also measured. The interfacial properties of PET fiber and PP matrix were indirectly represented by contact angle analysis. Results showed that the addition of TEOS is helpful in homogenizing the distribution of PP-g-MAH. Furthermore, TMPP generates an organic-inorganic &lsquo, armor&rsquo, structure on PET fiber, which can make up for the damage areas on the surface of PET fiber and strengthen each single-fiber by 14.4%. Besides, bending strength and modulus of TMPP-modified PET fiber-reinforced PP composite respectively, increase by 10 and 800 MPa. The compatibility between PET fiber and PP was also confirmed to be increased by TMPP. Predictably, this work supplied a new way for PET fiber modification and exploited its potential applications in composites.

Polytetrafluoroethylene (PTFE)/carbon black (CB) microporous membranes with excellent properties were successfully prepared via heterocoagulation process and mechanical stretching method. Heterocoagulation was achieved using PTFE emulsion with 26% solid content, an intermediate product of the commercial PTFE dispersions with 60% solid content, and CB dispersions to prepare PTFE/CB composite particles by mechanical stirring, which is the unique content in this article. Furthermore, in order to obtain uniform distribution of CB particles within the membrane matrix as well as improve color uniformity and mechanical strength of the microporous membranes, CB was pretreated by a titanate coupling agent (NDZ-201). The PTFE/CB composite particles were then used to prepare the PTFE/CB microporous membranes via mechanical stretching operation. Several important properties of the prepared PTFE/CB microporous membranes, such as tensile strength, porosity, contact angles, morphology, and dynamic mechanical properties, were investigated. Results showed that the fabricated PTFE/CB microporous membranes possessed color uniformity, high tensile strength, and high hydrophobicity.

Dual coordinated cross link networks were designed in epoxidized butadiene-acrylonitrile rubber (NBR)/CuSO4 composites to make commercial NBR become advanced soft materials. First, NBR was modified through organic peroxy acid method to produce epoxidized butadiene-acrylonitrile rubber (ENBR). Next, CuSO4 was introduced in bulk to form strong Cu2+-nitrile coordination bonds acting as strong cross link points and Cu2+-epoxy bonds acting as weak cross link points. XPS analysis, FT-IR spectra and rheological curves proved the dual coordination bonds. Curing rheology curves, crosslinking density and thermal properties effectively demonstrated the formation of related dual cross link networks. The ENBR/CuSO4 composites exhibited excellent mechanical properties due to the synergistic effect of strong and weak metal-ligand coordination networks. During stretching, the weak coordination bonds acted as sacrificial bonds which could dissipate energy, while the strong coordination bonds sustained the network and imparted the elasticity. Under the combined functions of dual coordination bonds, the modulus, tensile strength, and toughness of ENBR/CuSO4 composites could be improved and tuned by controlling the structure parameter of coordination networks such as epoxidation degree and content of CuSO4.

Silicone rubber (SR) composites filled with carbon black (CB) and carbon fibre (CF) were prepared. The effects of a single filler as well as hybrid fillers on the thermal conductivity (λ) and mechanical properties of SR composites were investigated. It was found that hybrid filler was more effective in increasing λ of the composite, and this effect was more pronounced when the weight ratio of CF:CB was 80:20. The scanning electron microscopy showed the hybrid filler formed a better filler network than single filler in the matrix. SR composites filled with hybrid fillers also possessed better mechanical properties compared with composites filled with only CF.

Nanosized Sb doped SnO2 (ATO) particles were successfully synthesized. Electrically conducting rubbery composites based on epichlorohydrin rubber (ECO) and two kinds of conductive fillers (SnO2 and ATO) were prepared by a conventional blending method. The morphology, structure and electrical conductivity of ECO/SnO2 and ECO/ATO composites were investigated. Results showed that SnO2 and ATO had great influence on the structure of ECO composite. Besides, the addition of oxide particles enhanced its electrical conductivity significantly. The electrical conductivity of ECO/ATO composite appeared an obvious threshold value with the variation of the loading amount of ATO fillers, whereas the resistivity of ECO filled with SnO2 decreased monotonically with the increasing SnO2. The temperature dependence of resistivity indicated that the ECO/SnO2 and ECO/ATO composites exhibited a negative temperature coefficient (NTC) effect. Scanning electron microscopy (SEM) was used to investigate the morphological states of oxide fillers in ECO matrix, and specifically continuous networks were observed. POLYM. COMPOS., 2015. © 2015 Society of Plastics Engineers

The effects of two types of carbon blacks (CBs), N990 and Vulcan XC-72, on the mechanical properties and thermal conductivity of filled silicone rubber (SR) were investigated. It was found that the addition of CB particles increased the thermal conductivity, the thermal stability and the tensile strength of the silicone rubber composites. The scanning electron microscope showed that Vulcan XC-72 of higher structure was more liable to form conductive network within the matrix, and the thermal conductivity of the composites filled by Vulcan XC-72 was superior to that of the composites filled by N990 at the same filler loading. The Agari model and the Payne effect were used to explain the influence of N990 and Vulcan XC-72 on the formation of thermal conductive networks. Furthermore, Vulcan XC-72 also had better enhancing effects on the mechanical properties and the electrical conductivity of the composites. It was notable that at the high filler contents, silicone rubber filled with N990 also possessed good general properties.

Acrylonitrile-butadiene rubber (NBR)/cobalt chloride (CoCl2) composites filled with carbon nanotubes (CNTs) were successfully prepared and investigated. The incorporation of CNTs markedly improved tensile strength and notably changed electrical properties of NBR/CoCl2/CNTs composites. The addition of CNTs brought by up to 39% and 101% improvements in tensile strength and hardness, respectively. Furthermore, the elongation at break maintained at high levels over 1000%. The volume resistivity decreased significantly with increasing CNTs content; rather, the dielectric constant and dielectric loss increased. A low electrical percolation threshold of about 1.5 pph CNTs was observed in NBR/CoCl2/CNTs composites. These results reflected the formation of three-dimensional conductive networks in composites. SEM results demonstrated that CNTs were dispersed uniformly and had strong filler-matrix interaction with NBR matrix, which could be correlated with property improvements. Moreover, thermogravimetric analysis and dynamic mechanical analysis were also utilized to study the effect of CNTs on composite properties.

Continuous glass fibers were added through extruder head into recycled polyethylene terephthalate/polyethylene (r-PET/PE) alloy to form a composite named long fiber reinforced recycled thermoplastic (LFRT). By pressing plate, products similar to fiberglass were further made. Results of mechanical properties tests showed that the addition of glass fibers increased tensile and flexural strength of LFRT more than 3 and 7 times compared with that of basic material, respectively. In accord with interfacial properties exhibited by contact angle tests, differential scanning calorimetry and scanning electron microscope showed that raising extrusion and hot-pressing temperature resulted in the improving of compatibility between glass fibers and alloy. Dynamic mechanical analysis reported that glass fibers improved the heat deflection temperature greatly.

In our previous report, poly(methyl vinyl ether-alt-maleic anhydride) grafted CB (GCB) with stable dispersion in water was successfully prepared. In the present study, waterborne polyurethane (WPU) nanocomposites including GCB and attapulgite (ATT) were prepared by liquid mixing method. Anionically charged GCB nanoparticles were heterocoagulated on the surface of cationically charged ATT nanorods at low pH value and improved the stabilization of ATT nanorods in water as a dispersing aid. The microstructure development in matrix that depended on various weight ratios of the nanoparticles ultimately influenced the electrical conductivity and mechanical properties of WPU nanocomposites. Composites containing equal concentrations of GCB and ATT showed reduced electrical conductivity, but significant increase in storage modulus. When the weight ratio of GCB to ATT was 5:1, both electrical conductivity and storage modulus of composite were improved simultaneously. The percolation threshold of composites containing a 5:1 (w/w) GCB/ATT ratio was lower than that of composites with GCB alone. The proposed mechanism for the effect of GCB and ATT on electrical or mechanical behaviors in composite was discussed in details. The clear evidence of microstructure development was also observed by transmission electron microscope.

Carbon black (CB)/polymer composites with high refractive index (RI) were fabricated from poly(vinyl alcohol) (PVA) and covalently functionalized nano-CB (PVA-es-CB) by simple esterification reaction. Transmission electron microscopy showed that uniform aggregates of PVA-es-CB nanoparticles with a size smaller than 100 nm formed in the nanocomposite films. Ellipsometric measurements indicated that the PVA-es-CB/PVA composite films had a RI in the range 1.520–1.598 linearly increased with the PVA-es-CB volume content. Theoretical equation based on Lorentz-Lorenz theory provided reasonably close estimation of the refractive indices to the experimentally observed values. The hybrid films also revealed relatively good surface planarity, thermal stability and optical transparency.

The pH-responsive polyelectrolyte, named poly(methyl vinyl ether-alt-maleic anhydride) (PVM/MA), was grafted onto the surface of carbon black (CB) by ultrasonically degraded method. The effect of pH on the dispersion of PVM/MA grafted CB in water and waterborne polyurethane (WPU) was studied. Particle size of PVM/MA grafted CB and its transmission electron microscope images showed the increasing of pH in the suspension of grafted CB easily causes the aggregates of grafted CB. Furthermore, scanning electron microscope images showed grafted CB had better dispersibility than that of untreated CB in WPU emulsion or corresponding solid composite. When grafted CB was neutralized in aqueous solution, the compatibility between PVM/MA grafted CB and WPU got poor. In addition, the dispersion of grafted CB in solid composite could be controlled through tuning the composite resistance.

Influence of heat treatment and fillers on the heat distortion temperature (HDT) of poly(lactic acid) hybrid biocomposites was intensively studied through HDT testing, polarizing microscope (POM), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). With loading 20 wt % BF or 20 wt % talc, improvement of HDT in PLA composite was about 10°C comparing with neat PLA after heat treatment. Moreover, there was a great improvement (above 45°C) of HDT in PLA composites with loading 20 wt % BF and 20 wt % talc simultaneously after heat treatment. Transcrystallization was observed during heat treatment and isothermal crystallization of PLA composites with loading BF and talc simultaneously. There was no similar phenomenon in other PLA composite with loading only one filler. The possible mechanism of forming transcrystallization was proposed. DSC and DMA were also used to clarify the variation in HDT before and after heat treatment, and the results suggest that the crystallinity, modulus and glass transition changed, especially formation of transcrystallization played a key role in improvement of HDT in PLA composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

A UV absorbent was blended with virgin carbon black to prepare modified carbon black (m-CB) using a solid phase modification. The mixed solutions of poly(ethylene terephthalate) (PET)/CB and PET/m-CB were coated on glass substrates to fabricate light screening films. Scanning electron microscopy (SEM) showed that m-CB had better dispersibility than CB in PET matrix. Nonisothermal crystallization kinetics of virgin PET, PET/CB, and PET/m-CB films were investigated by differential scanning calorimetry (DSC). The data were described by a modified Avrami model. The results showed CB and m-CB acted as nucleating agents and increased the crystallization rate of PET. But due to the low crystallization capacity of copolymerized PET (co-PET) matrix, the nucleating effects were not as obvious as expected. The addition of 4 wt% m-CB improved the UV screening ability of the composite film significantly and just slightly increased their haze.

The mixed solution of poly (ethylene terephthalate) (PET)/carbon black (CB) and PET/modified CB (m-CB) were coated on glass substrates to fabricate light screening films. m-CB was prepared using a solid phase modification method through mechanical blending of CB and 2-(2′-Hydroxy-5′-methylphenyl)-benzotriazole (UV-P) in weight composition of 50 : 50. The results of dynamic light scattering (DLS), optical microscopy, and scanning electron microscopy (SEM) showed that the modification of CB obviously reduced the particle and aggregate sizes of CB, leading to better dispersion of m-CB in PET films. Fourier transform infrared spectroscopy (FTIR) proved that UV-P was grafted on CB after blending and changed the molecular structure of CB. Ultraviolet-visible-Infrared (UV-vis-IR) spectrophotometer tests showed that the UV/IR absorption property of the films improved obviously while the visible light transmittance reduced gradually with the increase of m-CB content from 0.5 to 6 wt%. Differential scanning calorimeter (DSC) results showed the addition of 4 wt% m-CB decreased the crystallinity of PET matrix, which effectively inhibited the destruction of the film transparency with the addition of more CB. POLYM. COMPOS., 2011. © 2010 Society of Plastics Engineers

This work study is the compatibility, phase structure, and component interaction of poly(lactic acid) (PLA) and glycidyl methacrylate grafted poly(ethylene octane) (GMA-g-POE denoted as mPOE) blend by Fourier transform infrared (FTIR) spectra, dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), and wide-angle X-ray diffraction (WAXD), respectively. All the binary blend compositions exhibit two distinct glass transition temperatures corresponding to the mPOE-rich and PLA-rich phases, respectively. Moreover, these two peaks approach each other with increasing mPOE content, indicating partial compatibility between the PLA and mPOE. Chemical reactions between the end carboxyl groups of the PLA and epoxy groups of the mPOE are considered as the driving force of the enhanced compatibility. They lead to an increase in viscosity of the blends and a decrease in the structural symmetry of PLA. This result brings about a decrease in the spherulite growth rate and the degree of crystallinity. Glass transition temperature (Tg) depression of mPOE is attributed to the negative pressure imposed on the dispersed rubber phase, resulting from differential contraction due to the thermal shrinkage mismatch upon cooling from the melt state. The negative pressure in the dispersed particles, in turn, would cause a dilational effect for the matrix ligament between the particles, and therefore increases the ductility and toughness of PLA.

Blends of PLA and linear low-density polyethylene (LLDPE) were compatibilized with glycidyl methacrylate (GMA)–grafted poly(ethylene-octene) copolymer (mPOE). Effects of compatilizer on phase structure of compatibilized PLA/LLDPE were studied by spreading coefficient calculation prediction, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and wide-angle X-ray diffraction (WAXD) analysis. The spreading coefficient calculations, based on experimental and calculated surface tension data, show that mPOE spreads on LLDPE extensively to encapsulate LLDPE completely, which is in good agreement with the results of DSC, SEM, and WAXD analysis. The chemical reaction between the end carboxyl groups or end hydroxyl groups of PLA and epoxy groups of mPOE, which is suggested as the driving force leading to an ideal interfacial adhesion between PLA and the dispersed phase, was confirmed by Fourier transform infrared ray (FT-IR) spectroscopy analysis.

A novel method was employed to modify the surface of carbon black (CB) by an organic small molecule in a Haake Rheomix mixer. The modified carbon black (MCB) was dispersed uniformly in poly(lactic acid; PLA). The crystallization behaviors of PLA, PLA/CB and PLA/MCB composites were investigated by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS) and polarizing optical microscopy. It is found that the addition of CB or MCB can influence the crystallization behavior of PLA. PLA/MCB has a faster crystallization rate and higher crystallization peak temperature than PLA/CB. For non-isothermal studies, Jeziorny and Mo equations were employed. The Mo equation can well describe the non-isothermal crystallization of the three samples. For PLA/CB and PLA/MCB composites containing 3wt% fillers, the nucleating activity for CB is about 0.32, and about 0.16 for MCB. All these results show that MCB is an effective nucleating agent. PLA/MCB has a higher nucl...

A novel method was employed to modify the surface of carbon black (CB) by an organic small molecule in a Haake Rheomix mixer. Jeziorny equation, the Ozawa model and Mo equation were employed to describe the non-isothermal crystallization process of poly (lactic acid) (PLA), PLA/CB and PLA/modified carbon black (MCB) composites. It is found that the Ozawa model fail to describe the non-isothermal crystallization process for PLA and its composites, while Jeziorny equation and Mo’s theory provide a good fitting. The comparison of crystallization kinetics between PLA/MCB and PLA through Lauritzen–Hoffman model indicates that there appears a transition from regimes II to III in PLA and PLA/MCB. The fold surface free energy σ e of PLA/MCB composite is higher than that of neat PLA, implying that the existence of nucleating agent is unfavorable for the regular folding of the molecule chain.

A type of grafted carbon black (GCB), prepared with a low molecular weight antioxidant compound by in-situ reaction, was dispersed in poly(ethylene terephthalate) (PET) by a melt-blending process. Dispersion of fillers, volume resistivity, and thermal properties were investigated using scanning electron microscopy, a high-resistance meter, differential scanning calorimetry, and thermogravimetric analysis, respectively. The results show that, compared with carbon black (CB) particles, GCB particles dispersed better in the PET matrix, whereas the conductivity percolation threshold of PET/GCB was higher than that of PET/CB. The addition of GCB or CB elevated the cold crystallization temperature of PET, reflecting the effectiveness of carbon fillers as nucleating agents. But carbon fillers decreased the crystallization enthalpy of PET during both heating and cooling process. Both CB and GCB elevated the starting temperature of thermal degradation of PET and increased the amount of residues for the composites ...

Polystyrene (PS)/carbon black (CB) composite microspheres were prepared using a modified CB, which was prepared by blending CB with a hindered phenol antioxidant Irganox 1330 in an internal mixer. Scanning electron microscopy indicated that the modified CB adsorbed on the surface of PS microspheres homogenously to form a raspberry-like morphology composite. The non-covalent binding of Irganox 1330 on the surface of PS microsphere was observed from the UV-Vis absorption spectrum in ethanol, while the fluorescence of PS was almost totally quenched by the binding of Irganox 1330. These results implied there were aromatic interactions between Irganox 1330 and the PS microspheres, which played a crucial role in the formation of composite microspheres.

The influence of the basic properties of carbon black, such as structure, panicle size, and surface activity on the vulcanization and mechanical properties of filled natural rubber compounds was investigated in detail. This is important for a better understanding of the rubber performance and the mechanism of reinforcement. In particular, the effect of carbon black surface activity, which was changed by introducing one kind of hindered amine light stabilizer on rubber reinforcement is emphasized.

Natural rubber filled with poly(sodium-4-styrenesulfonate) (PSS)-decorated carbon black (CB) by employing a latex compounding technique was prepared. The result of scanning electron microscope demonstrated that CB was uniformly dispersed in the matrix. Comparing to traditional dry compounding, an improvement in physical and mechanical properties was observed in the composites attributed to the homogeneous distribution of CB in matrix and an augment of bound rubber. Owing to the changes of the physical properties of CB surface, vulcanizate filled with oxidized CB via latex way exhibited higher mechanical properties. The resulting vulcanizates displayed a diminished interaction between fillers based on the consequence of strain dependence of storage modulus. Furthermore, a splendid wet-skid resistance was obtained in vulcanizates fabricated by latex compounding technique in comparison with vulcanizates prepared by traditional dry compounding. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42346.

The encapsulation of poly (n-butyl acrylates) (PBA) onto carbon black (CB) surface via ultrasonic irradiation initiating emulsion polymerization was investigated. The results showed that the route performed at ambient temperature can efficiently prepare PBA encapsulated CB as proved by the aggregation of PBA encapsulated CB in the precipitator of PBA. The surface properties of CB coated with PBA were analyzed by FT-IR and XPS. The content of PBA encapsulated on the CB surface reaches 11.87% determined by TGA. Compared with the conventional chemical modification of CB, it was found that the particle size of CB obtained by the present approach can be controlled, and dynamic light scattering results quantified that CB particles with narrower size distribution and smaller size were obtained. The PBA encapsulated CB can be dispersed uniformly in the polymer matrix.

In our work, highly surface-roughened quasi-spherical silver powders with controllable size and superior dispersibility, which have narrow size distribution and relatively high tap density, were successfully prepared by reducing silver nitrate with ascorbic acid in aqueous solutions. Gum arabic (AG) was selected as dispersant to prevent the agglomeration of silver particles. Furthermore, the effects of preparation conditions on the characteristics of the powders were systematically investigated. By varying the concentration of the reactants, dosage of dispersant, the feeding modes, synthesis temperature and the pH value of the mixture solution of silver nitrate and AG, the resulted silver particles displayed controllable size, different morphologies and surface roughness. The spherical silver powder with mean particle size of 1.20 µm, tap density of 4.1 g cm−3 and specific area value of 0.46 m2 g−1 was prepared by adjusting preparation conditions. The AG absorbed on the surface preventing the silver particles from diffusion and aggregation was proved by the ultraviolet spectra. Observations of SEM images showed that the as-prepared silver powders were relatively monodisperse silver spheres with highly roughened surface and the particle size was controllable from 1 µm to 5 µm, specific surface area value from approximately 0.2 m2 g−1 to 0.8 m2 g−1. X-ray diffraction (XRD) patterns, energy dispersive spectroscopy (EDS), x-ray photoelectron spectra (XPS) and thermal gravity analysis (TGA) demonstrated high crystallinity and purity of the obtained silver powders.

To improve the dispersion stability of carbon black (CB) in aqueous media, an anion vinyl monomer, namely potassium 4-vinylbenzoate (K-4VBA) was polymerized and coated on to the CB particles through ultrasonically assisted radical polymerization. FT-IR was used to detect the presence of poly(K-4VBA) on the CB surface. The TGA results indicated that the polyelectrolyte contents of the CB particles could reach 77.5% in weight. The TEM studies revealed that the surface morphologies for the coated polyelectrolyte. Combined aqueous electrophoresis and DLS studies confirmed that these polyelectrolyte modified CB particles had pH-dependent colloid stabilities, as expected. The modified particles were colloidal stable at high or neutral pH, but became aggregated at low pH.

International audience; Two melting peaks are generally observed in a heating scan for isothermally crystallized poly(lactic acid) (PLA)/carbon black (CB) and PLA/modified carbon black (MCB) composites. To investigate the origin of the above double melting behavior, the melting behavior after isothermal crystallization was analyzed with differential scanning calorimetry, wide-angle X-ray diffraction, and small angel X-ray scattering techniques. The double melting of the crystallized samples can be explained by the model of two populations of lamellae, the double peaks of low and high temperatures are contributed to the melting of the small lamellae produced by secondary crystallization and that of the major crystals formed in the primary crystallization process, respectively. Spherulitic growth rates of the neat PLA and PLA/MCB composite were analyzed and the occurrence of a regime transition was demonstrated. For the PLA, a clear regime transition was observed at around 125 °C. For the PLA/MCB, it occurred at 130 °C.