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., 37:2411–2416, 2016. © 2015 Society of Plastics Engineers

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 effect of peroxide on the thermal and crystallization properties of high-density polyethylene (HDPE) and HDPE/polypropylene (PP) blends has been investigated using differential scanning calorimetry and X-ray diffraction techniques (XRD). Gel permeation chromatography (GPC) was also employed to study the molecular weight distribution (MWD) of HDPE and HDPE/PP blends with or without dicumyl peroxide (DCP). It was observed that blending HDPE with PP increased the rate of crystallization as well as the crystallite size of HDPE, attributed to the lower molecular weight and melt viscosity of the system. A depression of the melting temperature, the degree of crystallinity as well as the rate of crystallization with increased DCP content, confirmed that crystallization was inhibited by the formation of cross-links and branches in the system. The GPC measurement revealed that the molecular weight and its distribution were influenced by the addition of DCP and/or PP to PE, resulting in the differences in the rate of crystallization, and the size and the degree of perfection of the crystallite.

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

Recycled poly(ethylene terephthalate) (R-PET) was blended with four types of polyethylene (PE), linear low density polyethylene (LLDPE; LL0209AA, Fs150), low density polyethylene (LDPE; F101-1), and metallocene-LLDPE (m-LLDPE; Fv203) by co-rotating twin-screw extruder. Maleic anhydride-grafted poly(styrene-ethylene/butyldiene-styrene) (SEBS-g-MA) was added as compatibilizer. R-PET/PE/SEBS-g-MA blends were examined by scanning electron microscopy (SEM), differential scanning calorimeter (DSC), dynamic mechanical analysis (DMA), and mechanical property testing. The results indicated that the morphology and properties of the blends depended to a great extent on the miscibility between the olefin segments of SEBS-g-MA and PE. Due to the proper interaction between SEBS-g-MA and LDPE (F101-1), most SEBS-g-MA, located at the interface between two phases of PET and LDPE to increase the interfacial adhesion, lead to better mechanical properties of R-PET/LDPE (F101-1) blend. However, both the poor miscibility of SEBS-g-MA with LLDPE (LL0209AA) and the excessive miscibility of SEBS-g-MA with LLDPE (Fs150) and m-LLDPE (Fv203) reduced the compatibilization effect of SEBS-g-MA. DSC results showed that the interaction between SEBS-g-MA and PE obviously affected the crystallization of PET and PE. DMA results indicated that PE had more influence on the movement of SEBS-g-MA than PE did. Copyright © 2010 John Wiley & Sons, Ltd.

The nonisothermal crystallization of poly(lactic acid) (PLA), PLA/carbon black (CB), and PLA/modified carbon black (MCB) composites were investigated using differential scanning calorimetry (DSC) analysis. The rate of crystallization and the spherulitic morphologies of the PLA and PLA/MCB composites during isothermal crystallization were investigated using DSC and observed by means of polarizing optical microscopy (POM), respectively. The results show that either CB or MCB acts as an efficient nucleating agent for PLA. The nucleation activities of CB and MCB were quantitatively determined. It is shown that MCB has higher nucleating activity than CB in PLA. An isoconversional method correlates the temperature dependence of the effective activation energy and was used to evaluate the effective activation energy of PLA and PLA/MCB composites. It is confirmed that MCB advances the nuclei density and promotes the crystallization rate of the PLA matrix significantly. In addition, an interesting phenomenon of the periodic cracks of PLA spherulites observed by using POM is reported. The unbalanced surface stresses arising from growth features and thermal shrinkage may be the two main factors accounting for the formation of target pattern cracks. POLYM. ENG. SCI., 50:1658–1666, 2010. © 2010 Society of Plastics Engineers

Carbon black (CB) modified with small organic molecules was filled in polypropylene (PP) matrix. The crystallization behavior and mechanical properties of PP/modified CB (MCB) composites were investigated. Compared with the original CB, MCB could be dispersed uniformly in smaller particle sizes in PP matrix, and MCB could act as a more effective nucleating, toughening, and reinforcing agent when it was filled in PP at low concentrations. Further increasing of MCB particles in PP matrix resulted in the decrease of impact and tensile strength of PP/MCB composites. It was inferred from DSC results that the existence of CB vand MCB in PP matrix could result in the decrease of crystallite size and degree of perfection of PP. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers

Poly(styrene-ethylene/butylene-styrene) (SEBS) was used as a compatibilizer to improve the thermal and mechanical properties of recycled poly(ethylene terephthalate)/linear low-density polyethylene (R-PET/LLDPE) blends. The blends compatibilized with 0–20 wt % SEBS were prepared by low-temperature solid-state extrusion. The effect of SEBS content was investigated using scanning electron microscope, differential scanning calorimeter, dynamic mechanical analysis (DMA), and mechanical property testing. Morphology observation showed that the addition of 10 wt % SEBS led to the deformation of dispersed phase from spherical to fibrous structure, and microfibrils were formed at the interface between two phases in the compatibilized blends. Both differential scanning calorimeter and DMA results revealed that the blend with 20 wt % SEBS showed better compatibility between PET and LLDPE than other blends studied. The addition of 20 wt % of SEBS obviously improved the crystallizibility of PET as well as the modulus of the blends. DMA analysis also showed that the interaction between SEBS and two other components enhanced at high temperature above 130°C. The impact strength of the blend with 20 wt % SEBS increased of 93.2% with respect to the blend without SEBS, accompanied by only a 28.7% tensile strength decrease. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Polymer-layered silicate nanocomposites have an attracting increasing attention over recent years because of their unique mechanical, thermal, and other properties. In this article, a new kind of natural rubber (NR)/organo-vermiculite (OVMT) nanocomposites were investigated. The vermiculite (VMT) was intercalated by cetyltrimethylammonium bromide with ball mill method. The intercalation led to an increase of the d₍₀₀₁₎ of VMT from 1.46 nm to 4.51 nm. NR/OVMT nanocomposites were prepared via a melt process in a HAAKE mixer and were analyzed by X-ray diffraction and scanning electron microscope observations. The mechanical properties of the vulcanized nanocomposites were tested. It was found that the tensile strength and the elongation at the breaking point of the NR/OVMT nanocomposites loading 15 phr of the OVMT reached 28.4 MPa and 623.2%, respectively. The 300% modulus, tear strength, and hardness (Shore A) of the nanocomposites increased with the increase of the OVMT loading. The thermal properties of the nanocomposites were investigated by dynamic mechanical analysis, and the results showed that the storage modulus and the glass transition temperature of the nanocomposites were increased. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers

The dynamic mechanical properties of blends of phenolic resin (PF) and acrylic rubber (ACM) were investigated. PF had good compatibility with ACM and played an important role in the damping of the ACM/PF blends. With the increase of PF content and molecular weight, the peak of loss factor (tan δ) of blends shifted to a higher temperature and became much wider, indicating the convenience to adjust the value of tan δ peak and the temperature range. Fourier Transform infrared spectroscopy detected that the intermolecular hydrogen bonding between the PF hydroxyl groups and the ACM carbonyl groups had made a great contribution to the improvement of damping. Compared with the organic small molecule used in our previous study, PF gifted the blends with equivalent damping performance and much better stability and a lower cost for the application of damping materials. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The effects of small molecule plasticizer of liquid acrylonitrile-butadiene rubber (LNBR) on coordination crosslinking reaction between acrylonitrile-butadiene rubber (NBR) and copper sulfate (CuSO₄) were investigated. Attenuated total reflectance infrared (ATR-IR), curing curves analysis, equilibrium swelling method, differential scanning calorimetry (DSC), tensile test, and scanning electron microscope (SEM) were used in this work. The ATR-IR analysis showed that the peak of restricted CN is more explicit in NBR/CuSO₄/LNBR system. The curing curve analysis showed that NBR/CuSO₄/LNBR has higher torque. The results of equilibrium swelling method and DSC displayed that NBR/CuSO₄/LNBR has higher crosslink density and glass transition temperature, respectively. And NBR/CuSO₄/LNBR has stronger tensile strength and longer elongation at break from tensile test. SEM revealed the reasons that the NBR/CuSO₄/LNBR has better mechanical properties. All the results showed that addition of an amount of LNBR to NBR/CuSO₄ system could accelerate the coordination crosslinking reaction between NBR and CuSO₄. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

The grafting of maleic anhydride onto carbon black surface based on the Diels–Alder addition via ultrasonic irradiation was investigated. Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA) were used to determine the chemical structure of the resulting products. The anhydride ring in the modified products can be opened into two carboxylic groups. Accordingly, the carboxylated carbon black was analyzed quantitatively through acid-based titration to determine the concentration of anhydride ring on the modified carbon black's surface. The grafted molecules amount calculated from the concentration of the anhydride ring was consistent with the results of TGA data. Comparison of zeta potential measurement demonstrated that there were more negative charges attached to the surface of carbon black after ultrasonic modification. TEM observations showed that the conglomeration degree of modified carbon black decreased more than that of initial carbon black. Copyright © 2008 John Wiley & Sons, Ltd.