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Hybrid nanocomposites based on organophillic montmorillonite (MMT) and ethylene–propylene–diene rubber (EPDM) have been prepared by a melt compounding process. From analysis by X‐ray diffraction and transmission electron microscopy, the rubber molecules were found to be intercalated into the galleries of organoMMT and the silicate layers of organoMMT are uniformly dispersed as platelets of 50–80 nm thickness in the EPDM matrix. Dynamic mechanical studies reveal a strong rubber–filler interaction in the hybrid nanocomposite which is manifested in the lowering of tan δ at the glass transition temperature. The hybrid nanocomposites exhibit great improvement in tensile and tear strength, and modulus, as well as elongation‐at‐break. Moreover, the permeability of oxygen for the hybrid nanocomposite was reduced remarkably. © 2002 Society of Chemical Industry

The aim of this study was to investigate the impact of consuming dairy yogurt containing Lactobacillus paracasei ssp. paracasei (L. paracasei), Bifidobacterium animalis ssp. lactis (B. lactis) and heat-treated Lactobacillus plantarum (L. plantarum) on immune function. A randomized, open-label, placebo-controlled study was conducted on 200 nondiabetic subjects. Over a twelve-week period, the test group consumed dairy yogurt containing probiotics each day, whereas the placebo group consumed milk. Natural killer (NK) cell activity, interleukin (IL)-12 and immunoglobulin (Ig) G1 levels were significantly increased in the test group at twelve weeks compared to baseline. Additionally, the test group had significantly greater increases in serum NK cell activity and interferon (IFN)-γ and IgG1 than placebo group. Daily consumption of dairy yogurt containing L. paracasei, B. lactis and heat-treated L. plantarum could be an effective option to improve immune function by enhancing NK cell function and IFN-γ concentration (ClinicalTrials.gov: NCT03051425).

Ethylene vinyl acetate copolymer (EVA) and monmorillonite (MMT) nanocomposites have been investigated as a function of vinyl acetate content and molecular weight of EVA and types of substituted alkyl ammonium of MMT. It is found that vinyl acetate content and type of substituted alkyl ammonium are important factors for the intercalation behaviour of MMT in MMT/EVA nanocomposite. Maleic anhydride grafted high‐density polyethylene was used as a compatibilizer to improve the intercalation behaviour of MMT. X‐ray diffraction and transmission electron microscopy were used to characterize the intercalation/exfoliation behaviour, and mechanical properties were measured. © 2003 Society of Chemical Industry

Elastomers such as polyurethanes usually possess low stiffness, and the addition of traditional fillers typically results in a moderate improvement. Aramid nanofibers (ANFs) represent one of the most promising nanoscale building blocks for high-performance nanocomposites. In this work, waterborne polyurethanes (PUs) have been reinforced with ANFs using two solution processing methods, namely, layer-by-layer (LBL) assembly technique and the vacuum-assisted flocculation (VAF) method. Record-high modulus of 5.275 GPa and ultimate strength of 98.02 MPa are obtained among all the reported PU based nanocomposites. We attribute such achievement to the similar molecular structures of ANFs with PUs which ensures a high affinity made possible by the manifold interfacial interactions. The formation of multiple hydrogen bonds due to the presence of amide groups with appropriate spacing in both components is confirmed by the computer simulation. Compared with the VAF method, it is found that LBL assembly allows a better load transfer, resulting in higher ultimate strength and stiffness. The VAF method shows advantages in improving the ultimate strength at low loadings of ANFs. We believe our work may not only lead to a new practical combination within the field of composite materials but also provide important implications for the future design of nanocomposites based on the innovative nanofillers.

Acrylonitrile-butadiene rubber (NBR) hybrid nanocomposites with organoclays were prepared by melt mixing, and their properties were compared with those of conventional rubber compounds filled with carbon black and silica. Based on X-ray diffraction and transmission electron microscopy, the NBR nanocomposites obtained were found to form generally an intercalated structure, although they formed an exfoliated structure when the organoclay content was low enough, <2 parts per 100 rubber. The NBR nanocomposite showed a simultaneous improvement in ultimate strength and stiffness, which is generally in a trade-off relation in rubbery materials. A characteristic fracture morphology of 'laminated boardtype' was observed for NBR nanocomposites instead of typical 'cross-hatched' morphology in conventional rubber composites. The NBR nanocomposites also showed much higher hysteresis and tension set.

Naturally available halloysite nanotubes (HNTs) with hollow nanotubular structures were used as reinforcement in poly(e-caprolactone) (PCL). The PCL/HNT nanocomposites were prepared by melt mixing the polymer with as-received HNTs up to 10 wt % in an internal batch mixer. Transmission electron microscopy analysis indicated that the HNTs were dispersed uniformly on the nanoscale throughout the PCL matrix. Differential scanning calorimeter studies revealed that the PCL crystallinity was decreased in the nanocomposites, and the HNTs dispersed in the PCL matrix led to an increase in the non-isothermal crystallization temperature of the PCL. Tensile and dynamic mechanical tests showed great enhancement in strength and stiffness at low HNT content, while still maintaining the ductility of the PCL. The glass transition temperature (T g ) of the pristine PCL was substantially increased with increase in filler loading, which indicates good reinforcing effect imparted by the addition of HNT. Melt rheological studies revealed that the nanocomposites exhibited strong shear thinning behavior, and a percolated network of HNT particles was formed.

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