Rubber nanocomposites, transitions

In the second part of this chapter, an illustrative example of PARAFAC analysis for three-way data obtained in an actual laboratory experiment is presented to show how PARAFAC trilinear model can be constructed and analyzed to derive in-depth understanding of the system from the data. Thermal deformation of several types of poly lactic add (PLA) nanocomposites xmdergoing grass-to-rubber transition is probed by cross-polarization magic-angle (CP-MAS) NMR spectroscopy. Namely, sets of temperature-dependent NMR spectra are measured under varying clay content in the PLA nanocomposite samples. While temperature strongly affects molecular dynamics of PLA, the clay content in the samples also influences the molecular mobility. Thus, NMR spectra in this study become a three-way... 

The experimental analysis of particulate-filled nanocomposites butadiene-styrene rubber/fullerene-containing mineral (nanoshungite) was fulfilled with the aid of force-atomic microscopy, nanoindentation methods and computer treatment. The theoretical analysis was carried out within the fiameworks of fractal analysis. It has been shown that interfacial regions in the mentioned nanocomposites are the same reinforcing element as nano-filler actually. The conditions of the transition from nano- to microsystems were discussed. The fractal analysis of nanoshungite particles aggregation in polymer matrix was performed. In has been shown that reinforcement of the studied nanocomposites is a true nanoeffect. 

This technique has found the following applications in addition to those discussed in Sections 10.1 (resin cure studies on phenol urethane compositions) [65], 12.2 (photopolymer studies [66-68]), and 13.3 (phase transitions in PE) [66], Chapter 15 (viscoelastic and rheological properties), and Section 16.4 (heat deflection temperatures) epoxy resin-amine system [67], cured acrylate-terminated unsaturated copolymers [68], PE and PP foam [69], ethylene-propylene-diene terpolymers [70], natural rubbers [71, 72], polyester-based clear coat resins [73], polyvinyl esters and unsaturated polyester resins [74], polyimide-clay nanocomposites [75], polyether sulfone-styrene-acrylonitrile, PS-polymethyl methacrylate (PMMA) blends and PS-polytetrafluoroethylene PMMA copolymers [76], cyanate ester resin-carbon fibre composites [77], polycyanate epoxy resins [78], and styrenic copolymers [79]. 

DSC scans of the elastomer and its composites exhibit glass transition temperature (Tg), melting point and crystallinity. Melting temperature and Tg have not been affected either in presence of conventional filler or nanofillers while heat of fusion or crystallinity considerably decrease in CNT reinforced NR nanocomposite due to interaction between CNTs and rubber matrix [89]. On the other hand, poly... 

Gu et al. prepared Octadecyl ammonium montmorillonite/natural rubber/cfs-1,4-polybutadiene (OMMT/NR7BR) nanocomposites by direct mechanical blending. Two tan 5 peaks corresponded to the small glass transition peak of BR at lower and that of NR at higher temperature (Fig. 32). Both of the NR and BR phase of OMMT/ NR/BR (4 mass %) showed lower tan 8 peak values than the NR/BR hybrids and tan 8 of NR phase shifted to higher temperature. These observations can be related to the decreased mobility of the rubber molecules due to the strong interaction between the rubber matrix and OMMT [111-113]. The tan 8 value of OMMT/ NR/BR (4 mass %) at 0 °C was slightly lower than that of the pure NR/BR, which indicated that the nanocomposite had better wet skid resistance properties [110]. 

Abolhasani, M.M. et al. (2014) Influence of miscibility phenomenon on crystalline polymorph transition in poly(vinylidene fluoride)/acrylic rubber/day nanocomposite hybrid. PloS One, 9 (2), e88715. 

Cellulose whiskers and microfibril-late d cellulose-NR DMA and mechanical properties The stiffness of the natural rubber was significantly increased above its glass-rubber transition temperature upon nanoparticles addition. The reinforcing effect was shown to be higher for nanocomposites with MFC compared to whiskers. [61]... 

Natural rubber (NR)-rectorite nanocomposite was prepared by co-coagulating NR latex and rectorite aqueous suspension. The TEM and XRD were employed to characterize the microstructure of the nanocomposite. The results showed that the nanocomposite exhibited a higher glass transition temperature, lower tan d peak value, and slightly broader glass transition region compared with pure NR. The gas barrier properties of the NR-rectorite nanocomposites were remarkably improved by the introduction of nano scale rectorite because of the increased tortuosity of the diffusive path for a penetrant molecule. The nanocomposites have a unique stress-strain behavior due to the reinforcement and the hindrance of rectorite layers to the tensile crystallization of NR [36]. 

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