Assuredly one of the most essential factors in the performance of these systems is the condition of the interface and interphase among the constituents of a given system. It has become clear that it is the interfaceinterphase, and the interactions which take place in this part of a system, which determine to a significant degree the initial properties of the material. In order to achieve leadership in the formulation and application of polymer composites, it is evident that in depth understanding of interfacial and interphase phenomena becomes a prerequisite. Included in that understanding is, interalia, a grasp of thermodynamic, dispersionforce and nondispersionforce interactions; adhesion phenomena at interfaces; the morphological and mechanical characteristics of interfaces and interphases; the time dependent variations in these characteristics; stateofthe science approaches to modifying, controllably, key interactions through the medium of surface modification by chemical and especially by electrical discharge methods; diagnostic methods capable of yielding quantitative information on surface and interface chemistry.
The Interfacia l Interaction s in Polymeric Composite s NATO ASI Series Advanced Science Institutes Series A Series presenting the results of activities sponsored by the NATO Science Committee, which aims at the dissemination of advanced scientific and technological knowledge, with a view to strengthening links between scientific communities The Series is published by an international board of publishers in conjunction with the NATO Scientific Affairs Divisio n A Lif e Sciences B Physic s Plenum Publishin g Corporatio n London and New York C Mathematica l and Physical Sciences D Behavioura l and Social Sciences E Applie d Sciences Kluwer Academic Publisher s Dordrecht, Bosto n and Londo n F Compute r and Systems Sciences G Ecologica l Sciences H Cel l Biology I Globa l Environmental Change Springer-Verlag Berlin, Heidelberg, New York, London, Paris and Tokyo NATO-PCO-DATA BASE The electronic index to the NATO ASI Series provides full bibliographical reference s (with keywords and/or abstracts) to more than 30000 contributions from internationa l scientists published in all sections of the NATO ASI Series Access to the NATO-PCO-DAT A BAS E is possible in two ways: - vi a online FIL E 128 (NATO-PCO-DATA BASE ) hosted by ESRIN, Via Galileo Galilei, I-00044 Frascati, Italy - vi a CD-ROM "NATO-PCO-DATA BASE " with user-friendly retrieva l software in English, Frenc h and German (©WT V GmbH and DATAWARE Technologies Inc 1989) The CD-ROM can be ordered through any member of the Board of Publishers or through NATO-PCO , Overijse, Belgium Series E: Applied Sciences - Vol 230 The Interfacia l Interaction s in Polymeri c Composite s edited by Güneri Akova h Department of Chemistry, Polymer Science and Technical Program , Middle East Technological University , Ankara, Turkey if Springer Science+Busines s Media, B.V Proceedings of the NATO Advanced Study Institut e on The Interfacia l Interaction s in Polymeric Composite s Antalya/Kemer, Turke y 15-26 June 199 Library of Congress Cataloging-in-Publication Data The I n t e r f a c i a l i n t e r a c t i o n s Giiner i Akova l i p 230) Includes cm — in polymeric (NATO A S I s e r i e s composites Series E, / edited Applied by sciences ; no index ISBN 978-94-010-4717- ISB N 978-94-011-1642- (eBook ) DOI 10.1007/978-94-011-1642- P o l y m e r i c c o m p o s i t e s S u r f a c e c h e m i s t r y P o l y m e r i c I I Series composites—Surfaces I Akovali, Guneri TA418.9.C6I545 1992 620 * — d c 92-41725 ISBN 978-94-010-4717- Printed on acid-free paper All Rights Reserve d ©199 Springer Science+Busines s Medi a Dordrech t Originally publishe d b y Kluwer Academi c Publisher s i n 1993 No par t o f th e materia l protecte d b y thi s copyrigh t notic e ma y b e reproduce d o r utilized i n an y for m o r b y an y means , electroni c o r mechanical , includin g photo copying, recordin g o r by any informatio n storag e an d retrieva l system , without writte n permission from the copyright owner TABLE OF CONTENTS ix PREFACE LIST OF PARTICIPANTS xiii GROUP PICTURE: -:xviii INTERFACES, INTERPHASES AND "ADHESION": A PERSPECTIVE L H Sharpe ASPECTS OF COMPONENT INTERACTIONS IN POLYMER SYSTEMS H P Schreiber 21 RHEOLOGY AT INTERFACES 61 B G de Gennes and F Brochard-Wyart INTERACTIONS AND PROPERTIES OF COMPOSITES (1) FIBRE-MATRIX ADHESION MEASUREMENTS -81 (2) ADHESION COMPOSITE PROPERTIES RELATIONSHIPS 95 M Nardin and J Schultz -5 THE ROLE OF INTERFACE AT THE WALL IN FLOW OF CONCENTRATED COMPOSITES U Yilmazer and D M Kalyon 107 APPLICATION OF SURFACE ANALYSIS TO HIGH PERFORMANCE POLYMERIC ADHESIVES AND COMPOSITES J P Wightman 125 SOME EXPERIMENTAL METHODS OF CHARACTERIZING SURFACES E Bayramli 151 CONTROLLED INTERPHASES IN GLASS FIBER AND PARTICULATE REINFORCED POLYMERS: STRUCTURE OF SILANE COUPLING AGENTS IN SOLUTIONS AND ON SUBSTRATES H Ishida 169 CONTROL AND MODIFICATION OF SURFACES AND INTERFACES BY CORONA AND LOW PRESSURE PLASMA J E Kleunberg-Sapieha, L Martinu, S Sapieha and M R Wertheimer 201 10 PLASMAS AND SURFACESA PRACTICAL APPROACH TO GOOD COMPOSITES E M Liston 223 11 PLASMA POLYMERIZATION OF ACETYLENE: A COATING TECHNIQUE FOR FIBRE REINFORCEMENT OF COMPOSITES W Weisweiler - 269 vi 12 PLASMA ENHANCED CVD OF AROMATICSSURFACE TREATMENT OF CARBON FIBERS TO OPTIMIZE FIBRE-MATRIX ADHESION E Ebert and W Weisweiler 287 13 SOME NOTES ON SURFACE MODIFICATION BY PLASMA G Akovali - 309 14 SCIENCE AND TECHNOLOGY OF POLYMER COMPOSITES L Nicolais, M Kenny, A.Maffezzoli, T Torre and A Trivisano - 321 15 REINFORCING FIBERS FOR COMPOSITES 3.P Wightman - 359 16 "IN SITU" COMPOSITES FORMED WITH LIQUID CRYSTALLINE POLYMERS AND THERMOPLASTIC MATRICES E Amendola, L Nicolais and C Carfagna - 387 17 SOME SHORT COMMUNICATIONS OF PARTICIPANTS: 409 A OPEN QUESTIONS ON EFFECTS OF FIBRE-MATRIX INTERACTIONS ON COMPOUND AND COMPOSITE PROPERTIES B R Scholtens - 411 B INTERFACE STABILIZATION IN POLYMER BLENDS BY MEANS OF BLOCK AND GRAFT COPOLYMERS M Fischer 415 C INTERFACIAL CHEMICAL INTERACTIONS IN CONDENSATION POLYMERS AND THEIR BLENDS S Fakirov and M Evstatiev 417 POLARIZATION AND ITS DIAGNOSTIC D INTERFACIAL SIGNIFICANCE IN POLYMERIC COMPOSITES G Banhegyi 421 E ON THE PHYSICAL NATURE OF INTERFACIAL LAYER IN POLYMER COATINGS M R Kiselev and V M Starsev 431 F THE EFFECT OF CORONA MODIFICATION ON THE COMPOSITE INTERFACES S Sapieha 433 G PERCULARITY OF FILM-FORMING AND HYDROLYTIC DECAY OF TIN-CONTAINING POLYMER COATINGS Z M O Rzayev, R R Abdullayev and V A Zubov 435 vii H DIFFUSION OF METAL IONS IN CARBOXYLIC POLYMER SORBENTS OF DIFFERENT MORPHOLOGIC STRUCTURE A A Efendiev I ADSORPTION OF 437 METHYLENE BLUE ON PVC-DOP-NATURAL ZEOLITE COMPOSITES D Balkose, S Ulku OPTICALLY TRANSPARENT 439 GLASS FIBER REINFORCED POLY (METHYLMETHACRYLATE) LAMINATES R K Six, O Stoffer and D E Day K THE EFFECT OF RECYCLING ON THE 441 PROPERTIES OF C A Bernardo, A M Cunha and M Oliveira 443 THERMOPLASTICS COMPOSITES L CARBON FIBERS FROM METHANE M T Sousa and L Figueiredo PREFACE Polymer composites represent materials of great and of continuously growing application appears importance to be Their limitless potential They have been for the subject of numerous studies both at academic and industrial levels Much progress has been made in the incisive formulation of composites; sophisticated methods of property evaluation have been developed in the past decade and many, largely empirical solutions have been proposed to resolve the problem of their long-term performance under typical conditions of use (i.e the use of silane or titane coupling agents to enhance adhesion within composite materials) Assuredly one performance of of these the most systems essential is the factors condition in the of the interface and interphase among the constituents of a given system It has become clear that it is the interface/interphase, and the interactions which take place in this part of a system, which determine to a significant degree the initial properties of the material achieve polymer In order to leadership in the formulation and application of composites, it is evident that in depth understanding of interfacial and interphase phenomena becomes a prerequisite Included in that understanding is, interalia, a grasp of thermodynamic, non-dispersion-force interactions; dispersion-force and adhesion phenomena at interfaces; the morphological and mechanical characteristics of interfaces and interphases; the time dependent variations in these characteristics; state-of-the science approaches to modifying, controllably, key interactions through the medium ix x of surface modification by chemical and especially by electrical discharge methods; diagnostic methods capable of yielding quantitative information on surface and interface chemistry Fortunately, in importance of the factors response to listed here, the evident intensi ve research activity has taken and is taking place in the Universities of the Nato countries Resident in these locations, and at certain industrial sites, are experts, who are able to disseminate information of high value to a wide number of scientists and engineers, whose task is to evaluate further the technology and the applications of material composites This Nato-ASI meeting is proposed as an outstanding vehicle for congregating leading workers in the field, with the view of meeting the targets of incisive information transfer to a critical and critically involved audience Therefore it functions both as a means of direct transfer of information to concerned parties and as a means of publishing a compendium of information The Institute considered the interfacial interactions in polymeric composites and for this, first a differentiation between adhesion, interfaces and interphases is made; which included the discussion of the adsorption-mechanical (hooking)-electrostatic and diffusion theories of adhesion, as well as the rheological theories of adhesive joints The concept of interface engineering, "consisting of a systematic understanding of the interface, controlling of the interface and tailoring of the properties" are extensively discussed It is concluded that, there are postulation a of number the of simple difficulties relationships involved between interactions and the mechanical performances in the surface A tentati ve model is purposed to relate the interfacial strenghts to the level of physical interactions, mainly to electron donor-acceptor interactions at the interface The mechanical properties of polymer/polymer interfaces are shown to be very sensi ti ve to the detailed structure of the interface and two major examples of this correlation presented are: xi the role of chain ends and their spatial distribution in A/A healing as well as the role of entanglements in A/B fracture or in A/B slippage The influence of interactions at polymer surfaces systems, and interfaces on the properties of polymer with emphasis on the acid-base interactions, are all reviewed in detail Several contributions review the methods of investigation of interfacial interactions and surfaces The IGC method to evaluate the donor-acceptor interaction potential of components, as well as the classical techniques such as SEM, Auger, SIMMS, ion scattering and X-ray photoelectron spectroscopy Various surface FT-IR techniques are extensively discussed and explained with applications A new qualitative method (induction time approach) to study the trans crystal layers is also introduced various strategies to control and modify surfaces and interfaces including in modifications, physical, particular chemical corona and and inherent cold plasma techniques are reviewed and discussed extensively Description of the mechanical properties of polymer composites are also made by considering the properties of particulate-long fiber and laminate composites through the different models generated in the literature It is shown that, many advantages can be derived by use of liquid crystalline compounds as reinforcing fillers to produce blends with engineering thermoplastics During the meeting, there were also a number of presentations of students Some of these are included in the book, too Finally, myself, I on would behalf like of to the thank organizing to all committee and lecturers for fulfilling their share in putting the parts together, to the participants for their active contributions and involvement as well as for creating the lively environment for the meeting Our special thanks are due to Nato-ASI for making it all possible, and to the Basic Sciences and BAYG Groups of Turkish National and Scientific Research Council 440 adsorption of methylene blue is a diffusion controlled process as indicated by linear dependence of fractional uptake on square root of time in Figure The diffusion coefficient (D) was calculated from experimental uptake data using Equation (1) where Mt amount adsorbed at time t; M ,amount adsorbed at equi!~br~u~i 1, half of the layer thickness It is found that it was 3.7xlO ms and it was nearly independent of zeolite concentrations 0.8 0.7 !i! M 0.6 0.5 0.4 phr Zeolite W 10 /!; 20 EI 40 0.3 0.2 0.1 10 20 30 t 1/2 h 1/2 Figure 1.Fractional uptake of methylene blue versus square root of time The degree of fusion of the plastisol and the extent of wetting of the zeolite particles by the plastic matrix affects the rate of diffusion and extent of adsorption of methylene blue whic are preferantially adsorbed on zeolites Experimental work indicated that addition of zeolites to PVC plastisols created an interface accessible to aquous solutions REFERENCES Wagner,M.P.(1978)'Natural and synthetic silicas in plastics' in R.Deanin(ed), Additives for Plastics,Academic Press,London pp9-28 Ajji A.,Schreiber HP (1987), 'Rates of property change in plasticized filled PVC compounds' , J App Polym.Sci ,33, 2493-2501 Kokta B V• ,Maldas D., Deneault T., Beland P (1990) , 'Composites of Poly(vinyl chloride) and wood Fibers', Polymer Composites, 11, 84-89 Park G.S.(1986) 'Transport principles-solution,diffusion and permeation in polymer membranes' in P.M.Bungay (ed), Synthetic Membranes: Science ,Engineering and Application, D.Reidel Pub.Com.,London,pp 57-107 Optically Transparent Glass Fiber Reinforced Poly(methylmethacrylate) Laminates R.K Six, 1.0 Stoffer, and D.E Day Dept of Chemsilry 142 Schrenk Hall University ofMissomi at Rolla Rolla, MO 6S401 Abstract: Transparent composites have been made at the University of Missouri-Rolla, USA The refractive index of optical glass fibers was adjusted to match the refractive index of poly(methyl methacrylate) for the middle of the visible spectrum at 25 ·C A 1.S mm thick composite made in this manner containing 8% glass fiber has 80% transmission and fonns clear images of distant objects Dissimilar thennooptic coefficients (dnldT) between the glass and PMMA cause a decrease in transmission as a function of temperature change However there is good transmission of light over a broad temperature range (approx ±2S ·C from the temperature at which the refractive index was matched between the glass and the PMMA) These composites are made by two processes: a polymerized in place method, and by hot pressing glass fiber/pMMA prepregs to fonn Jaminates The hot pressing process allows fiber to be placed on the surfaces of a cast sheet of PMMA core Since bending stresses occur at or near the surfaces this results in increased strength with less fiber and therefore a more highly transparent composite 441 G Alcovali (ed.), The Interfacial Interactions in Polymeric Composites, 441 © 1993 Kluwer Academic Publishers The effect of recycling on the properties of thermoplastics composites C.A.Bernardo, A.M.Cunha and M.J.Oliveira Department of Polymer Engineering, University of Minho 4719 Braga Codex - PORTUGAL The recycling of plastics waste has received an increased interest in the last few years, due to an increasing perception of the environmental impact of plastics, namely as packaging materials In particular, the primary recycling of plastics waste (which is done directly in the industry to produce parts whose properties are similar to those of the original products), has been the subject of various recent publications [1-41, some of which devoted to the deduction of algorithms to predict the properties (and the economics) of mixtures of virgin and recycled polymers[l,31 The interest of these studies, specially with engineering plastics, is obvious, as in this case it is critical to compatibilize the maximum incorporation of recycled material with adequate values of the specified property Moreover, this type of research may help to elucidate the nature of the degradation mechanism Figure represents, in a schematic way, a continuous operation of plastics processing, such as injection moulding, incorporating a recycling/granulation step In the figure, a,V,F and represent, respectively, the stream of recycled, virgin, feed and output material, and P, Po' Pn and Pn the values of the corresponding properties (the subscript n refers to the nth cycle) In the derivation of the algorithms we assumed that the properties of the mixtures of virgin and recycled polymers obey one of two general laws These are: linear law (additive mixture) 443 G Akovali (ed.), The Interfacial Interactions in Polymeric Composites, 443-448 © 1993 Kluwer Academic Publishers 444 and logarithmic law ln Pn - k ln Po + r ln Pr Recycled (Pr) R {r RIF) = GRANULATION Output (Pn) Q =F I PROCESSING Feed (Pn) I F = R+V Virgin po Iymer (Po) V (k = v/F) Fig l - Schematic representation of a processing/recycling operation The algorithms also imply that the degradation of the properties of the material in each processing cycle (considered to be the set of all the steps between two consecutive feeds), may be described by a general equation, usually different for each material and each property, that is integrated in the expression that gives the properties of the mixture Various degradation equations have been described in the literature [1,3] In this work, we used only of these equations, which, in our experience, are applicable to a large range of materials and properties The corresponding algorithms are: a) Degradation equation in the form of an exponential decay (Pi - Po e- bi ) and additive mixture: [model 1] b) Degradation equation in the form of an exponential decay to an assimptotic value, p (Pi - ao e-bi + Pal and additive mixture : 445 c) Logarithmic law of mixtures and loss of property in each processing step obeying a power law (Pi-Cpod): Pn _ C (l-(rd)n)/(l-rd) P * [model 3] with, In the derivation of the above algorithms, r (and k - 1-r) is supposed to be the same in all cycles, and Pi represents the value of the property in the output of the ith processing The property loss in the granulation process is not normally considered but, when significant, can be easily included by incorporating its effect in the degradation equation In the case of thermoplastics composites reinforced with glass or carbon fibres, besides the equations that represent the degration of the mechanical properties (or the changes in the molecular weight of the polymer in the matrix), the decrease in the length of the fibres must also be known This can be done by burning the polymer after each processing/granulation step, and observing, by optical microscopy, the resulting ashes In the present work we report the study of the effect of recycling on the properties of two engineering plastics, a glass fibre reinforced polypropylene, produced by ICI (Propathene HW60 GR20; 20% W/W) and a glass fibre reinforced polycarbonate, produced by GEP (Lexan SOOR; 10%W/W) Some of the results obtained with the polypropylene are presented in Table and Figures and Table - Variation of the second moment of the distribution of fibre lengths (Lw) with the number of cycles (dimensions in 11m) n Lw(Polypropylene) 710 610 540 480 380 330 260 280 250 259 Lw(Polycarbonate) 270 260 167 149 133 108 140 99 446 Pn/Po * 0.8 + -"'~;::: - 0.6 + -~-~C~:g:::::::;;et=::::fl 0.4 + - - - - - - - 0.2 + - - - - - ,.,~ -~~- x - _.- - O+ . -. r -r -r -r ~ ~-~ o Experimental: Number of cycles o Tenlile strength o Impac:t strength The oretica l: ( model 2) * Tensile strength X fibre length k k = 0.5 Fig.2 - Variation of the mechanical properties and fibre lengl PP/20% GFR with the number of processing/granulation cy In Figure each property - tensile strength, impact strengtl fibre length - is normalised with the value of the one correspo to the virgin polymer The lines correspond to model 2, which the best fit to the experimental values Although the length fibres (determined as the second moment of the distributic lengths, measured in the optical micrographs) decreased to 3( that of the virgin polymer after cycles, it remained always h than 250 ~ It can be observed that, even when no virgin mat , was added between cycles (k- O), the values of the mech~ properties of the composite stabilize around 58% of those oj original material When the fraction of virgin polymer in the increases to 50% (k-0.5) the tensile strength after cycles i of that of the original material and remains constant from the SEM observations of fracture surfaces show that most of the f : are broken close to the surface, without debonding from the ma 447 In this case, the effect of the fibres in the perfomance of the composite is additive, as predicted in various theoretical formulations [5], and confirmed by the present results It can also be observed that model decribes adequately the variation of both the mechanical properties and the length of the fibres with the number of cycles, and can thus be used to predict the properties of the mixtures The loss of impact strength of the 10%(W/W) glass fibre reinforced polycarbonate with the number of processing/granulation cycles is presented in Figure 3, which also shows the variation of the length of the fibres with recycling It can be observed that, unlike the previous case, the value of the property decreases pratically to zero after only cycles Although the length of the fibres stabilizes after cycles, its value diminishes from ca 270 ~ (n-O) to 130 ~ (n=4) This value is apparently lower than that of Lcr (critical fibre length), below which, when the composite fails, the fibre's debond from the matrix without breakage In fact, values of Lcr between 125 and 200 ~ have been reported in the literature [6,7] Hence, in this case, the fibres not contribute towards the overall mechanical properties of the composite, but act instead as stress concentrators, leading to catastrophic failure It can also be observed that one of the algorithms (model 3) describes quite well both the loss of impact strength and the reduction of fibre length In this work we presented a methodology that can be used to predict the properties of thermoplastics composites made with mixtures of recycled and virgin polymers The algorithms developped perform equally well when recycling leads to a catastrophic failure of the properties or when these properties stabilize after a number of cycles 448 Pn/Po o Experimental: Theoretical: 34567 * 10 Number of cycles Impact strength (k = 0) - model o Fibre length - - model Fig.3 - Variation of the mechanical properties and fibre length of PC/10% GFR with the number of processing/granulation cycles Refarence [1] Throne, J.L., Advances in Polymer Technology 7,347 (1987) [2] Wandhal,W., Proc Conf Plastics Recycling 88, Copenhagen, comm 24.1, SPE- Scandinavian Section (1988) [3] Bernardo, C.A., Tecnometal 70, 13 (1990) [4] La Mantia,F.P., Macplas, 53, May (1990) [5] Yam,K.L., Gogoi,B.K., Lai,C.C and Selke,S.L., Polym.Eng.Sci 30, 693 (1990) [6] Filbert,W.C., SPE Techical Papers 14,3 94(1968) [7] Yang,H.W., Farris,R.and Chien, J.C., J.Appl.Polym.Sci.23, 11, (1979) CARBON FIBERS FROM METHANE M TERESA SOUSA, J.L FIGUEIREDO Faculdade de Engenharia (LCM/DEQ) 4099 Porto codex, Portugal Carbon fibers were produced from methane by a CVD process in two stages: 1- Growth of carbon filaments by hydrocarbon decomposition catalysed by metal particles; 2- Thickening of these filaments by pyrolytic carbon deposition The mechanism proposed for the initial stage of filament growth is the following [1]: a) Adsorption of the carbonaceous reactant at the metal surface, followed by decomposition reactions leading to chemisorbed carbon species; b) Carbon dissolution in, and diffusion through, the metal particles to active growth areas (such as grain boundaries or metal-support interfaces) where carbon precipitates out As a result, metal particles are detached from the surface and transported on top of the growing filaments; c) Alternatively, the carbon species may react on the surface of the metal to originate a film of "encapsulating" carbon; consequently, the catalyst deactivates and filament growth ceases The filaments grow with a diameter which is close to that of the catalyst particles at their tips In the second stage, carried out at higher temperature, the filaments stop growing as a result of catalyst deactivation, but they thicken by carbon deposition due to the pyrolysis of the hydrocarbon, becoming fibers The experiments were conducted in a mixture of 30% methane in hydrogen Iron supported on grafoil (® Union Carbide) was used as catalyst, submitted to an appropriate temperature programme [2] Fibers were produced with diameters in the range 5-15Jlm and lengths up to cm Characterization of these fibers is in progress, using the available techniques for determination of physical and chemical properties The most important parameters are total surface area, active surface area (ASA), porous texture, surface energy and surface functional groups Carbon fibers are used as reinforcement material in composites, the mechanical properties of which are dependent upon the matrix/fiber adhesion Surface modification such as dry or wet oxidation of the carbon fibers may be used to improve those characteristics [3] Oxidation in boiling HN03 and in air is being studied and the results have been evaluated in terms of their influence on structure and surface oxygen concentration Wet oxidation (HN03) does not affect the fibers surface, but an significant increase in the surface oxygen concentration (_ %) is detected as shown by the XPS spectrum presented in Figure Dry oxidation experiments were carried out in air at 600 °C to different extents of burn-off Even at low burn-off level the surface morphology is strongly affected showing pits (Figure 2) The results of these experiments as well as those of anodic oxidation will be analysed in terms of total surface area, ASA and strength of the carbon fibers 449 G Akovali (ed.), The InteT/aciallnteractions in Polymeric Composites, 449-450 © 1993 Kluwer Academic Publishers 450 1400 " I 1200 C 1000 D U n t 800 600 400 200 0 200 400 600 800 Binding Energy / eV 1000 1200 Figure : XPS spectrum of carbon fibers oxidised in boiling HN03 during 12 hrs Figure : Carbon fibers: left original, right after oxidation in air at 600 °C, B.O = % REFERENCES Figueiredo, J L and Bernardo, C A (1990) "Filamentous carbon fonnation on metal and alloys" in J L Figueiredo, C A Bernardo, R T K Baker and K J Hiittinger (eds), Carbon Fibers Filaments and Composites, Kluwer Academic Publishers, Dordrecht, pp 441-457 Benissad, F., Gadelle, P , Coulon, M and Bonnetain, L (1988) " Fonnation de fibres de carbone a partir du methane: I-Croissance catalytique et epaississement pyrolytique ", Carbon,22, 61-69 Fitzer, E and Weiss, R (1987) "Effect of surface treatment and sizing of C-fibers on the mechanical properties of CFR thennosetting and thennoplastic polymers", Carbon 25., 455-467 INDEX A Ablation; 260 Acid-Base Theory; 28 Adhesion; 1, 125, 192, 282, 298, 375 Energy; 100 Polymer-Polymer; 215 Theories; 6, 375 Adhesive Joints; Pressure; 100 Ageing; 258 B Bagley; 110 Brown Model; 66 Blend; 417 c Capillary Flow; 110 Carbon Fiber; 162, 287, 359, 449 Casing; 10, 252 Chemical Modifications; 48 Chemorheology; 349 Component Interactions; 22 Composites; 160, 257, 312, 338, 411, 433, 443 Concentrated; 107 In Situ; 387 Constitute Equation; 118 Contact Angle; 152, 281 Corona; 46, 201, 433 451 452 D Debonding; 142 Diffusion Theory; E Electrostatic Theory; Electron Microscopy Scanning; 127 Scanning Transmission; 128 Auger; 131 Electron Spin Resonance (ESR); 297 ESCA; 164 F Failure; 15, 139 Fracture; 61 Fragmentation; 89 Friction; 72 Filament Winding; 324 Fluoronation; 12 G Gutman Probe; 30 Grazing Incidence Diffraction (GID); 297 H Healing; 61 Hooking Theory; Interface; 1, 42, 61, 82, 107, 160, 171, 415, 417, 431 453 Interphase; 2, 126, 160, 169 Rheology; 61 Interfacial Polarization; 421 Interaction; 81, 411 component; 22 Acid-Base; 34 Parameters; 22 Interlaminar Shear Strength (ISS); 83, 285 Induction Times; 38 Ion scattering Spectroscopy (ISS); 133, 126, 210 Iosipesen Test; 84 Inverse Gas Chromotography (IGC); 23 Inherent Modifications; 52 L Lap-Shear; 140, 256 Laminate; 328, 388 Liquid Crystal; 388 M Micro Droplets; 85 Micro Identation Test; 88 Modification; 201, 260, 309, 433 N Non-Dispersive Interaction; 53, 301 p Parallel Disk; 109 Peel strength; 43 Photoacoustic; 130 Plasma; 47, 201, 223, 309 Polymerization; 269 454 Enhanced CVD; 287 Pull-Out Test; 85 pultrusion; 341 R Raman; 91 Recycling; 310, 443 Resin Transfer Molding; 341 Rheology Theory; 9, 108 At Interfaces; 61 Of Blends; 396 s SEC; 177 Simulated Wetting; 152 Silane; 169, 173 Chemisorbed; 181 Physisorbed; 184 Solubility Parameter; 22 Slip; 61 Velocity; 113 Layer; 121 Spectroscopy Auger Electron (AES); 126, 131 Ion scattering (ISS); 126, 133, 210 Scanning Electron (SEM); 127, 210 Secondary Ion Mass (SIMS); 134, 375 Surface Reflectance (SRS); 129 Scanning Transmission Electron (STEM); 128, 210 X-Ray Photoelectron (XPS); 135, 252, 277, 295 Photoacoustic FTIR (PAS-FTIR); 130, 210 Rutherford Backscattering, 130, 210 Surface Analysis; 125, 151 Suppression of Slippage; 72 455 Suspension; 107 Surfaces High Energy; 157 Low Energy; 156 Carbon Fiber;162 Synergism; 40 T Tangential Slip; 70 Tensiogram: 163 Termokinetic Model; 346 Transverse; 85 Transmission Electron Microscopy (TEM);364 Transcrystallinity; 5, 12, 102 Toughness; 61, 69 Treatment; 10 True Viscosity; 117 w Wettability; 207, 254 ... transformed into conplex and locally varying modes of loading in the interfacial region c) In many joints there is interpenetration (diffusion) of the materials Therefore, no interface exists and true interfacial. .. convincing The point to be made is that the interphase is a useful concept in attempting to understand the mechanical and other behavior of adhering systems, for the reason that interphases do, in. .. strength (the breaking stress, the performance) of an adhesive joint is determined by the mechanical properties of the materials COII'Prising the joint and the local stresses in the joint It is