An in situ intercalative polymerization method for preparing UV curable clay–polymer nanocomposites

A novel in situ intercalative polymerization technique was used to disperse clay mineral in a precursor resin for use in UV curing by performing an in situ ion exchange reaction during polyesterification. Unmodified montmorillonite (MMT) was added to a reaction mixture composed of monomers and methyl, tallow, bis‐2‐hydroxyethyl ammonium (MTEtOH) during the synthesis of unsaturated polyesters to create resins containing highly dispersed, organically modified MMT. UV‐curable clay–polymer nanocomposite (CPN) films were then prepared utilizing donor–acceptor chemistry through reactions of the unsaturated polyester resin with triethylene glycol divinyl ether. Functional group conversion improved up to 15% by the incorporation of clay mineral into the polymer matrix through the in situ polymerization method. The CPNs also had improved barrier, mechanical, and thermal properties over a control film containing no clay mineral. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42601.     

Design and preparation of cross‐linked α‐methylstyrene acrylonitrile copolymer nanoparticles and their interfacial investigation with rubber

Cross‐linked α‐methylstyrene and acrylonitrile (MStAN) copolymer particles in a latex form were synthesized by free radical emulsion polymerization. The particles showed a narrow size distribution and an average diameter of 65 nm. The amount of the vinyl groups at the surface of the (MStAN) copolymer particles resulted from varied amount of the initiator (APS) and the cross‐linking agent (DVB) was detected by iodine titration method. When filled into ethylene propylene rubber (EPR), the MStAN nano‐particles exhibited excellent reinforcing capabilities, and with the increase of the vinyl groups at the surface of MStAN particles, the tensile stress of MStAN/EPR increased. Results demonstrated that the vinyl groups at the surface of the (MStAN) copolymer particles provided certain chemical interactions between the filler particles and the macromolecular chains of rubber matrix. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41914.     

Reaction of carbon fiber sizing and its influence on the interphase region of composites

What might happen with the interphase region of composite if the sizing agent cannot afford the attack of processing temperature and firstly reacted before its combination with the resin, is rarely reported. On the basis of this, herein, effects of sizing reaction on the interphase region of composite were investigated, as well as on the carbon fiber surface properties. It showed that the interfacial shear strength of carbon fiber/epoxy composite was improved after the sizing reaction. The interphase modulus was also increased with a thinner gradient distance. Further analysis indicated that the fiber surface roughness increased, the fiber wettability with the resin lowered, and the chemical reactions between sizing agent and resin reduced after 200°C/2 h treatment on carbon fiber. These results explained the change of the interphase region, which are meaningful for sizing optimization. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41917.     

Crystallization kinetics of thermoplastic elastomeric blends based on ground tyre rubber

This work analyzes the crystallization process of thermoplastic elastomeric blends (TPE) based on ground tyre rubber (GTR). More specifically it analyzes the effect of GTR and fresh rubber materials, like ethylene propylene diene monomer (EPDM) and ethylene propylene rubber (EPR), on the crystallization of binary and ternary polypropylene (PP)‐based blends. The crystallization kinetics is studied under isothermal and nonisothermal conditions using differential scanning calorimetry (DSC). The kinetic parameters derived from the Avrami model are used to study the effect of temperature and rubber materials on the nucleation mechanism, the morphology of the crystalline structures, and the crystallization rate. Results reveal that GTR has a strong nucleating effect on PP and that its presence leads to higher crystallization rates. The EPDM presence has a slight effect on the PP crystallization process whereas EPR has no significant effect. From the DSC curves it is possible to detect an inverse relationship between temperature and the crystallization rate. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42589.     

Facile fabrication of superhydrophobic polyimide/polytetrafluoroethylene composite coatings with high water adhesion

A facile casting method was used to fabricate superhydrophobic polyimide/polytetrafluoroethylene composite coatings with high water adhesion. The water contact angles of the composite coatings were larger than 150 °, expressing superhydrophobic property. But water droplets pinned tightly on the composite coating, even if it was upside down. The X‐ray photoelectron spectrum analysis indicated that polyimide and polytetrafluoroethylene coexisted in the resulting coating. The observation with scanning electron microscopy showed that the composite coating formed lotus‐like structure with many spherical polyimide papillae randomly bonding on the surface. But the tops of the polyimide papillae were not covered by lance‐shaped Teflon fibres, forming an inhomogenous and discontinuous surface structure. This special surface chemical distribution and lotus‐like structure combined to contribute to the high adhesive superhydrophobicity. This simple method may greatly extend the application range of high adhesive superhydrophobic surfaces in microcontrollable and microfluidic application. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42810.     

The flame‐retardant properties and mechanisms of poly(ethylene terephthalate)/hexakis (para‐allyloxyphenoxy) cyclotriphosphazene systems

Para‐allyl ether phenol derivative of cyclophosphazene (PACP) was prepared and used as a filler to modify the flame‐retardant properties of poly(ethylene terephthalate) (PET) by melting‐blending. The mechanism of flame‐retardant was discussed and the influences of flame‐retardant contents to the mechanical properties were studied. The results revealed that the incorporation of only 5 phpp PACP (0.37 wt % phosphorus containing) into PET matrix can distinctly increase the flame retardancy of PET/PACP composition, and it has a little effect on the mechanical properties of PET. The high flame‐retardant performance of PET/PACP composite was attributed to the combination of condensed‐phase flame retardant and gas‐phase flame retardant. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42711.     

Processing and properties of phthalic anhydride modified soy protein/glycerol plasticized soy protein composite films

Phthalic anhydride modified soy protein (PAS)/glycerol plasticized soy protein (GPS) composite films were fabricated by using extrusion and compression‐molding. Modified with phthalic anhydride, the soy protein lost its thermoplastic ability and was used as a filler to reinforce the GPS matrix. Fourier transform infrared spectra, optical transmittance, scanning electron microscope, mechanical tests, water resistance tests, as well as thermo‐gravimetric analysis were carried out to investigate the structure and properties of PAS and the plastic composites. The similar chemical structure of PAS and GPS led to compatibility of the two components resulting in high transparency and enhanced tensile properties of the composites. The water resistance of GPS was also improved by the incorporation of PAS. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42221.     

Fabrication of a low‐cost nano‐SiO2/PVC composite ultrafiltration membrane and its antifouling performance

A novel low‐cost SiO₂/Polyvinylchloride (PVC) membrane with different nano‐SiO₂ particles loading (0–4 wt %) was prepared by the phase‐inversion process. The optimum nano‐SiO₂ dosage was determined as 1.5 wt % based on the casting solution compositions, the membranes' mechanical properties and hydrophilicities, the pure water fluxes, microstructures, and absorption of protein. Compared with the bare membrane, the membrane with 1.5 wt % nano‐SiO₂ addition presented better capabilities against the protein absorption and bacterial attachment, better antifouling performance, and higher flux recovery ratio in filtration of the supernatant liquor which collected from a secondary sedimentation tank in a municipal wastewater plant. The SiO₂/PVC membranes have applicable potential in the municipal wastewater treatment for their low price, good antifouling performance and high removal efficiencies of SS (over 97.2%), COD (up to 82.9%) and total bacteria (more than 93.6%). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41267.     

Preparation and characterization of graphene oxide reinforced PVA film with boric acid as crosslinker

PVA films were prepared through aqueous solution method, and boric acid (BA) as well as graphene oxide (GO) was added to improve the mechanical and thermal properties. It was found that 5 wt % BA could increase the tensile strength threefold (from 23.3 to 67.7 MPa), and the incorporation of 0.2 wt % GO would provide additional percentage growth of 30% (from 67.7 to 88.5 MPa). Moreover, an enhancement of thermal stability of PVA film was found when BA or GO filler was added. The reinforcement mechanisms of both BA and GO were investigated, and a competitive phenomenon that the addition of BA would influence the reinforcement effect of GO sheets was found. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42000.     

Polycarbonate‐based composites reinforced by in situ polytetrafluoroethylene fibrillation: Preparation,thermal and rheological behavior

Fibrillar reinforced composites of polytetrafluoroethylene (PTFE) and polycarbonate (PC) were prepared by in situ fibrillation of PTFE into PC matrix using twin screw extruder. Different samples were obtained by varying the relative ratio between PC and PTFE. The rheological properties of the PC/PTFE composites were found to depend on concentration of the PTFE fibrils. The melt strength analysis in nonisothermal conditions was also studied. The increase in force and decrease in drawability with increasing the PTFE content are associated with the PTFE fibrils formed in situ during the thermomechanical process in twin screw extruder. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42401.