Polymer nanocomposites description

The discrepancy indicated requires the application of principally differing approaches to the polymer nanocomposites melt viscosity description. Such an approach can be fractal analysis, within the ffamewoik of which, the authors used the following relationship for fractal liquid viscosity (h) estimation ... 

As the adduced above data have shown, the polymer nanocomposites with three main types of inorganic nanofiller and also polymer-polymeric nanocomposites melt viscosity caimot be described adequately within the fiamework of models, developed for the description of microcomposites melt viscosity. This task can be solved successfully within the framework of the fractal model of viscous liquid flow, if in it the used nanofiller special feature is taken into account correctly. Let us note that unlike microcomposites nanofiller cotents enhancement does not result in melt viscosity increase, but, on the contrary, reduces it. It is obvious, that this aspect is very important from the practical point of view. 

A description of various characterization techniques for studying the dispersion of nanoparticles, curing kinetics and thermal degradation will facihtate the readers better understanding of these techniques. Information on the applications of polymer nanocomposites in various fields has also been incorporated. 

This chapter reviews the use of the sepiolite/palygorskite group of clays as a nanofiller for polymer nanocomposites. Sepiolite and palygorskite are characterized by a needle-like or fiber-like shape. This peculiar shape offers unique advantages in terms of mechanical reinforcement while, at the same time, it allows to study the effect of the nanofiller s shape on the final composite properties. The importance of the nanofiller shape for the composite properties is analyzed in Section 12.2, introducing the rationale of the whole chapter. After a general description of needle-like nanoclays in Section 12.3, the chapter develops into a main part (Section 12.4), reviewing the preparation methods and physical properties of polyolefin/needle-like clay nanocomposites. 

Although the shape memory properties of the polymer nanocomposites were not explicitly described for all of these nanocomposites, many of the materials have independently been shown to have shape memory properties and the descriptions of the polymer nanocomposites from the year 2000 remain relevant today for the field and ongoing research. 

In 2004, a comprehensive volume was edited by Utracki that provides a thorough description of the thermodynamics, polymer mechanics, and composite mechanics of clay-containing polymer nanocomposites [69]. In 2012, Woodhead Publishing led by editor Gao published an extensive review of recent advances in polymer nanocomposites [80]. Chapter 11 of that book describes in detail the progress made in the manufacture and characterization of thermoplastic... 

The connectivity and spatial arrangement of objects within a network stmcture and the resulting macroscopic effects can be described by the percolation theory. In all its variations the percolatimi theory focuses on critical phenomena that originate from the spatial formation of a network and result in sharp transitions in the behaviour of the system of interest (Kirkpatrick 1973). Percolation models have been applied with various degrees of success to the description of the electrical behaviour of polymer nanocomposites. In these systems the insulating polymer matrix is loaded with cmiductive filler whose network formation leads to a sharp insulation-conductor transition (Lux 1993). Experimental work and theoretical predictions have established that the system s conductivity o follows a power-law dependence in accordance with percolation theory... 

The performed analysis has shown that at the consideration of semicrystalline polymers with devitrificated amorphous phase as natural hybrid nanocomposites their abnormally high reinforcement degree is realized at the expense of crystallites partial recrystallization (mechanical disordering), that means crystalline phase participation in the formation of these polymers elastic properties. It is obvious, that the proposed mechanism is inapplicable for the description of reinforcement of polymer nanocomposites with inorganic nanofiller. 

The authors of Ref [9] conducted cross-linked polymers microhardness description within the frameworks of the fractal (structural) models and the indicated parameter intercommunication with structure and mechanical characteristics clarification. The epoxy polymers structure description is given within the frameworks of the cluster model of polymers amorphous state structure [10], which allows to consider polymer as natural nanocomposites, in which nanoclusters play nanofiller role (this question will be considered in detail in chapter fifteen). 

Bashorov, M. T, Kozlov, G. V, Mikitaev, A. K. (2010). Polymers as Natural Nanocomposites Description of Elasticity Modulus within the Frameworks of Micromechani-cal Models. Plast Massy, Nii, 41 3. 

Hence, the results stated in the present chapter give a purely practical aspect of the application of such theoretical concepts as the cluster model of the amorphous state structure of polymers and fractal analysis for the description of the structure and properties of polymers treated as natural nanocomposites. The goal-directed creation of the necessary nanostructure allows polymers to be obtained whose properties are just as good as (and even exceeding) those of composites. Structureless (defectless) polymers are the most perspective in this respect. Such polymers can be a natural replacement for a large number of polymer nanocomposites elaborated at present. 

This chapter reviews the major theoretical descriptions and fundamental experimental research on the electrical properties of polymer nanocomposites with cylindrical and rodlike fillers. A number of comprehensive surveys of existing theoretical and experimental studies have recently been published. Thus, the emphasis here is on highlighting key stmcture-property relationships and the underlying mechanisms as well as identifying the major gaps in the current understanding. This chapter is organized as follows To motivate our smdy, Section... 

This chapter is organised as follows Following this introduction as section 1, a brief description of the synthesis and characterisation techniques used for the as-synthesised polymer capped selenide nanopartides is given as section 2. In section 3, the mechanism of the reaction, results and discussion of the different selenide nanocomposites obtained using different polymers are given. Section 4, the last section gives a summary of the whole process, followed by references. Acknowledgements are cited before references. 

Choudhury et al. [36] in their work on hydrogenated nitrile butadiene rubber (HNBR)-nanoclay systems showed the thermodynamic aspects of nanocomposite formation using the mean-field-lattice-based description of polymer melt intercalation, which was first proposed by Vaia and Giannelis [37]. Briefly, the free... 

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