Catalytic grafting: A new technique for polymer‐fiber composites. III. Polyethylene‐plasma‐treated Kevlar^TM fibers composites: Analysis of the fiber surface

Abstract

SYNOPSISIn this article, plasma-treated KevlarTM fiber-polyethylene composites prepared by the catalytic grafting technique were studied. The reactive groups -COOH, -OH, -NH, generated on the Kevlar fiber surface by oxygen plasma treatment were used to chemically anchor Ziegler-Natta catalyst, which was then followed by ethylene polymerization on the fiber surface. The surface structure of the Kevlar fibers, untreated or treated by oxygen plasma, catalyst grafted, or ethylene polymerized, was characterized by X-ray photoelectron spectroscopy (XPS ) , attenuated total reflection ( ATR) , and scanning electron microscopy (SEM) . The morphology, interfacial behavior, and mechanical properties of the highdensity polyethylene (HDPE) composites reinforced by either catalytic grafted or ungrafted Kevlar fibers were investigated by means of differential scanning calorimetry (DSC) , polarized light optical microscopy, tensile testing, and SEM. Special attention was devoted to the tensile properties of the composites in the direction transverse to the fibers. The experimental results show that oxygen plasma treatment increases the reactive site concentration on the fiber surface significantly and that the composites reinforced by catalytically grafted Kevlar fibers exhibit higher tensile strength both parallel and transverse to the fibers. The improved interfacial adhesion is attributed to the interfacial chemical bonding established by catalytic grafting.

Mechanical behaviour of highly filled lignin/polyethylene composites made by catalytic grafting

“…After the polymerization process each fibre or filler particle is encapsulated by the polymer. Thls technique has been successfully used with a polyethylene matrix and several kinds of additives: asbestos fibres (Wang et al, 1992a), plasma treated UHMPE fibres (Wang et al, 1992b), plasma treated KevlarTM fibres (Wang et al, 1993), hydrolysed KevlarTM pulp (Rajabian and kt-Kadi, 1995), glass beads, wood fibres and others.…”

Improvement of interfacial adhesion of poly(m-phenylene isophthalamide) short fiber-thermoplastic elastomer (SEBS) composites by N-alkylation on fiber surface

“…[3][4][5][6] Plasma treatment has also been used to create a functional group on Kevlar and hence to provide bonding with the matrix. [7][8][9][10] One chemical method used to modify the surface of aramid fiber is the metalation reaction of the fiber surface to form polyanions, which is then followed by reaction with some functional groups or the grafting of suitable polymer segments. [11][12][13][14][15] Short-fiber reinforced thermoplastic elastomers have recently gained much attention due to their attractive properties.…”

Influence of plasma surface treatments on kink band formation in PBO fibers during compression

“…Additionally, O1s and N1s displace 0.3 eV towards higher BE for ZN4 and 0.7 eV towards smaller BE for ZO4. Therefore, the signal observed at 288.2 eV for C1s profiles corresponding to ZO4 and ZN4 may be associated to oxidized carbon like CN,36 HNCO37 and/or HOCO,38 according to the literature related to organic polymers and functionalized carbon materials (summarized in Table IV).…”