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Nanocomposite materials differ from the traditional composite materials in that they provide enhanced properties at comparatively low filler loading with respect to microsize filler. In this research work, silica filled polypropylene micro and nanocomposites were prepared and compared in terms of their thermal properties. Both composites were prepared by the melt blending method using a Thermo Haake internal mixer. Later, the epoxy resin was used as a dispersing aid to improve the adhesion between silica and polypropylene. For comparison purposes, 1% and 2% w/w of nanosilica filler is assumed to be comparable to 10% and 20% w/w of microsilica filler. Both composites at various compositions of fillers were subjected to thermal analysis including differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). From DSC analysis, the melting point of micro and nanocomposites remain almost the same as neat polypropylene. By adding the nanosize filler into the composite system, an increase in the degree of crystallinity was observed. In general, the nanocomposites exhibited comparable or better properties over the microcomposites. The employment of epoxy resins as a dispersing aid has adversely affected the properties of the composites (i.e., nano and microcomposites). However, the results were encouraging at relatively low levels of filler loading.

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Mechanical strength in the cable sheath is particularly valuable for both fiber optical and copper pair cable. By bonding a PVC jacket to a coated metal tape, a mechanically strong sheath construction is obtained. Changes in PVC jacket technologies have created the need for PVC compatible coated metals with greater tolerance for variations in PVC jacketing materials. This need has been met by the development of a variety of coated metals having thermoplastic coatings which adhere to PVC. As a consequence of this development, new cable sheath designs for use in a variety of applications, such as riser cable and direct buried cable destined for local area networks, are possible. These cables may utilize both copper conductors and/or optical fibers for signal transmission. Data will be provided in the paper to show the effects of extrusion process conditions on adhesion for a variety of PVC resins. The properties of a variety of coated metals—aluminum, copper, and steel—will be discussed. Data on environmental tests of adhesion will be presented. Relationships between adhesion, metal characteristics, jacket properties, and mechanical performance of the sheath will be discussed. Cable applications for the PVC compatible metals will be discussed. Data on the performance of the bonded sheath in riser cable and buried local area network cable will be presented. New cable applications where coated metals in the sheath can provide lightweight armoring will also be discussed.

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