Search

The modification of polymer chain ends is important in order to produce highly functional polymers. A novel chain-end modification of polymer iodides (Polymer-I) via reversible complexation-mediated polymerization (RCMP) with different functionalized radical generation agents, such as azo compounds and organic peroxides, was developed. This reaction was comprehensively studied for three different polymers, i.e., poly (methyl methacrylate), polystyrene and poly (n-butyl acrylate) (PBA), two different functional azo compounds with aliphatic alkyl and carboxy groups, three different functional diacyl peroxides with aliphatic alkyl, aromatic, and carboxy groups, and one peroxydicarbonate with an aliphatic alkyl group. The reaction mechanism was probed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The combination of PBA-I, iodine abstraction catalyst and different functional diacyl peroxides enabled higher chain-end modification to desired moieties from the diacyl peroxide. The dominant key factors for efficiency in this chain-end modification mechanism were the combination rate constant and the amount of radicals generated per unit of time.

The effect of the amount of 2,2′-Bis(2-oxazoline) on the spectral, thermal, morphological, and tensile properties of polypropylene (PP)/liquid crystalline polymer (LCP)/maleic anhydride grafted PP (PP-g-MAH) blends was investigated. A wholly aromatic LCP having a low melting point, namely a AL-7000 copolyester was used, because it also uses a compatibilizer with a low decomposition temperature. As the amount of 2,2′-Bis(2-oxazoline) increased, the dispersibility of the LCP improved and the tensile properties were improved, but when it was added in excess, a loss in function was observed. In particular, when 0.5 wt% of 2,2′-Bis(2-oxazoline) were added, the tensile strength and elastic modulus were the highest, and cohesive fracture (fracture within the matrix, not at the PP/LCP interface) was observed in the scanning electron microscope image.

A series of wholly aromatic copolyesters P-IPAx with low melting point (Tm) derived from hydroxybenzoic acid (HBA), 6-hydroxy-2-naphthoic acid (HNA), 4,4'-dihydroxy-biphenyl (BP), terephthalic acid...

This work developed an electrically conductive thermosetting resin composite that transitioned from a liquid to solid without using solvents in response to an increase in temperature. This material has applications as a matrix for carbon fiber reinforced plastics. The composite comprised polyaniline (PANI) together with dodecyl benzene sulfonic acid (DBSA) as a liquid dopant in addition to a radical polymerization system made of triethylene glycol dimethacrylate with a peroxide initiator. In this system, micron-sized non-conductive PANI particles combined with DBSA were dispersed in the form of conductive nano-sized particles or on the molecular level after doping induced by a temperature increase. The thermal doping temperature was successfully lowered by decreasing the PANI particle size via bead milling. Selection of an appropriate peroxide initiator also allowed the radical polymerization temperature to be adjusted such that doping occurred prior to solidification. Optimization of the thermal doping temperature and the increased radical polymerization temperature provided the material with a high electrical conductivity of 1.45 S/cm.

Previously impregnated and stored carbon fibres i.e. prepregs are a breakthrough in the composites industries. Prepregs are extremely convenient for industrial growth. Until now epoxy-based CFRP has been the focus of the industries. This report discusses a new conductive yet inexpensive resin which can be utilized in the form of prepregs owing to its long-term stability. The major prepreg enabling properties like thermal stability, rheological properties and storage effect are studied in detail. Finally, the preliminary results of the mechanical and electrical properties of the CFRP are also encompassed in this report.

Methacrylate group containing acid is explored as a curable dopant material for the synthesis of structural composites with polyaniline (PANI). The performance of this material is evaluated using various characterisation techniques to analyse how the material behaves with PANI. Thermal microscopy, UV–Vis spectroscopy, FTIR spectroscopy, differential scanning calorimetry show promising results of doping of PANI and subsequent curing of the composite. After detailed quantification, the composites were also tested to verify the electrical and mechanical properties, which gave significantly enhanced results with suitable viscosity of the resin.

The surface of carbon fibers (CFs) is often modified by multi-walled carbon nanotubes (MWCNTs), and the effect of the interface on the mechanical properties has been reported mostly for epoxy matrices. We achieved effective surface modification of CFs by a simple two-step process to graft a large amount of MWCNTs using a highly reactive polymer to enhance the bonding between CFs and MWCNTs. The first step was the reactive mono-molecular coating of a reactive polymer (poly-2-isopropenyl-2-oxazoline; Pipozo) that has high reactivity with COOH from CFs and MWCNTs. The high reactivity between the oxazoline group and COOH or phenol OH was confirmed for low-molecular-weight reactions. The second step was the coating of MWCNTs from a dispersion in a solvent. This simple process resulted in a substantial amount of MWCNTs strongly bonded to CF, even after washing. The MWCNTs grafted onto CFs remained even after melt-mixing. The effect on the interface, i.e., physical anchoring, led to an improvement of the mechanical properties. The novelty of the present study is that Pipozo acted as a molecular bonding layer between CFs and MWCNTs as a physical anchoring structure formed by a simple process, and the interface caused a 20% improvement in the tensile strength and modulus. This concept of a composite having a physical anchoring structure of MWCNTs on CFs has potential applications for lightweight thermoplastics, such as in the automotive industry.

Polystyrene (PS) has low impact strength and also shows poor strain hardening. In this work, poly(styrene–butadiene–styrene) triblock copolymer (SBS) was solution- and melt-blended with PS in the presence of a free-radical polymerization initiator, dicumyl peroxide (DCP), to enhance PS’s thermal stability, mechanical properties, impact resistance, and strain hardening. The solution-blended PS/SBS containing 0.1% DCP annealed at 180 °C showed strong strain hardening, but the melt-blended PS/SBS annealed at the same temperature and time showed poor strain hardening. The change in the blending temperature, DCP concentration, and PS-to-SBS ratio had minimal effect on the strain hardening of melt-blended PS/SBS. The tensile strength increased with an increase in the concentration of DCP up to 0.1%, and beyond that level, the tensile strength started decreasing. The impact resistance considerably improved with an increase in the SBS loading in the PS matrix, and the enhancement was more than double of the impact resistance shown by the neat PS.

This work establishes the fact that Polyaniline (PANI) contributes to cationic scavenging on the polymerization of a cross linking polymer, i.e. Divinylbenzene (DVB), resulting in a significant change in the properties of the PANI-based DVB resin system. Furthermore, it is also shown that the cationic scavenging is directly related to the degree of doping of PANI and its dispersion state. Various intermediate doped PANI was added with a fixed amount of DVB to prepare thermosetting matrices. The degree of doping of PANI was assessed with the DSC, FT-IR, and UV-VIS-NIR analyses before mixing with DVB matrix. It has been shown that the Polyaniline (PANI) agglomerates broke and a uniform dispersion was obtained with an increased degree of doping, which led to more exposed amines groups of PANI. These groups acted as scavengers to the cationic polymerization of the DVB monomer. DSC and viscosity measurement of the uncured PANI-DBSA/DVB resin system confirmed the scavenging effect of PANI on the curing profile and subsequently to the electrical and mechanical properties of the cured composites. This paper presents a detailed analysis of the advantages and disadvantages of the scavenging behavior of PANI in the context of preparing PANI-based polymer composites.

We conducted research aimed at combining diamond particle surfaces with external moieties using a polymer. We here propose an effective solution using a reactive polymer, poly (2-vinyl-2-oxazoline) (Pvozo), with a large amount of reactive oxazoline as side chains. The idea is that some of the oxazoline groups react with carboxylic acid at the surface and the other oxazoline groups remain as available unreacted groups for further reaction with external moieties. The chemical reactivity of oxazoline with carboxylic acid was confirmed by nuclear magnetic resonance (NMR) and Fourier transform infrared (FT-IR) spectroscopy using model low-molecular-weight molecules, followed by reaction between Pvozo and the surface. The amount of acid groups on the surface was determined by titration. Diamond particles reacted with Pvozo in a solvent, followed by a washing step, which resulted in the formation of a uniform monolayer of nanosized Pvozo on micron-sized diamond particles, which was confirmed by thermogravimetric analysis (TGA) and by a visible-marker method with scanning electron microscopy (SEM) using carbon nanotubes. The amounts of reacted and unreacted oxazoline of Pvozo on the surface were quantified using nonanoic acid in conjunction with TGA.

A liquid crystalline polymethacrylate having two cyclohexylphenyl mesogens on its side-chain (PMG0) was synthesized by the radical polymerization of the corresponding methacrylate monomer (MG0). PM...

Solution processing of thin film encapsulation (TFE) has been a long anticipated technology to bridge the big idea of flexible organic electronics to become real world values, since only small-sized flexible devices are currently achieved with expensive multilayered TFE by complex vacuum processing. Highly demanding conditions are to carry out the process under inert gas, at a low temperature, and without aggressive chemicals to avoid damages to the organic materials. Here we show for the first time a solution-processed TFE to totally equal the level of conventional glass-cap encapsulation to achieve a "ready-to-be-used" stability of an organic light emitting diode (OLED). A seamless organic/inorganic multilayer in a structure such as polydimethylsiloxane (PDMS)/SiO

Electrowetting on dielectric (EWOD) devices were fabricated using two hydrophobic organic fluoropolymers, comprising CYTOP (a product name) having different chemical structures only at the terminal functional groups. These devices were subsequently characterized by applying a range of direct current (DC) voltages. The data demonstrated that the EWOD performance was dramatically improved upon incorporating a CYTOP polymer having highly polar terminal functional groups, as compared to a polymer having terminal groups with lower polarity. The new finding about the positive effect of highly polar terminal functional groups on the enhancement of EWOD was exhibited through various careful experiments, changing only the quantitative amount of polar terminal functional groups while keeping other factors constant (thickness, substrate, etc.).

Carbon fiber reinforced plastics (CFRPs) are prone to severe damages by lightning strikes due to their low electrical conductivity. Current lightning strike protection (LSP) technology generally consists of metal foils/films on the surface of composite airframe structures. The present work aims to introduce all polymeric conductive layer for LSP of CFRP structures. Intrinsic conductive polymer i.e. Polyaniline (PANI) is used to make a thermosetting polymer mixture. CFRPs coated with this electrically conductive, all polymeric layer was tested against simulated lighting strike. It has been shown that PANI-LSP specimens dissipated the lightning current effectively and provided enough residual mechanical properties of CFRPs.

A roll milled complex of Polyaniline (PANI) and Dodecylbenzenesulphonic acid (DBSA) is used with a cross-linked polymer Divinylbenzene (DVB), to prepare a conductive thermoset matrix with good environmental stability at room temperature. Upon heating, thermal doping of PANI-DBSA and curing of DVB occur simultaneously. Different amounts of DVB are used to prepare different samples and their properties are determined. Electrical & mechanical properties are measured. It has been shown that the electrical properties and mechanical properties of the composites are inversely proportional. It is demonstrated that the flexural modulus increases with an increase in DVB content, while the conductivity increases with an increase in PANI-DBSA content. The composite using roll-milled PANI-DBSA complex has shown better stability but lower electrical and mechanical properties as compared to the composite prepared using centrifugally mixed PANI-DBSA complex. An environmentally stable PANI-DBSA/DVB conductive thermosetting matrix is introduced in this work. FTIR spectra and UV–vis–NIR spectra are obtained to explain the effect of roll milling on PANI-DBSA and also the effect of DVB concentration on the composite. Thermal stability of the composites is determined using TGA analysis. The morphology of the samples is studied using SEM and the conductivity behavior is explained.

Conductive polymers have garnered extensive attention over the last few decades owing to their vast applications and relative ease of production. One such polymer is PANI; with versatile thermo-mechanical, chemical, and electrical properties, has been researched for varied applications in the field of electronics, electrodes and corrosion protection. In this study, we focus on an alternative route to process semi-doped PANI/DBSA complexes with special focus on material properties for improved processability. This study investigates the influence of two different material preparation techniques: roll-milling and thermal-doping, on the formability and processability of such polymer-complex systems. Results confirm similar doping levels achieved in both processes and shear-thinning behavior was only observed for roll-milled samples. These results underline the formability of roll-milled PANI/DBSA with thermosetting resins. It essentially explains the production route and offers a perspective for commercial manufacturing.

Polyaniline (PANI) is one of the most studied intrinsic electrically conductive polymer in recent years. In the present work, PANI-based conductive composites have been prepared using dodecylbenzenesulphonic acid (DBSA) as a dopant and divinylbenzene (DVB) as a cross-linking polymer to enhance the rigidity. In this mixture, DBSA acts as the dopant of PANI as well as the curing agent of DVB, and this means that doping and curing of the composite occur simultaneously. PANI–DBSA mixture has been prepared by physical mixing using centrifugal mixer. The ratio of PANI and DBSA has been kept constant in weight ratio 30:70. Furthermore, DVB content has been varied to prepare the different samples. It has been found that with the increase in DVB content, a good dispersion of PANI–DBSA/DVB solution is achieved. However, significant improvement in the electrical conductivity of the samples is observed with the increase in PANI content. Mechanical flexural test has been performed on the prepared samples using a three-point bending configuration. It has been found that the flexural modulus and brittleness of the prepared samples increase with the increase in the content of DVB in the composite. Morphology of the composite surfaces has been also studied and it has been found that low concentration of DVB results into a poor dispersion and hence agglomeration of PANI–DBSA in composite can be seen clearly in the images.

Si O C ceramics were prepared from a methyl silicone preceramic polymer and rice bran by a simple method. Dried rice bran powder was blended with a molten preceramic polymer (Silres 610) at various ratios by a Brabender-type static mixer. Composites were made from them by crosslinking at 250 °C in a hot press and porous ceramics were made by pyrolysing them at 900 °C. The produced porous ceramics were characterised by measuring their density, ceramic yield, volume shrinkage, hygroscopic expansion, and compressive strength. Additionally, the fabricated ceramics were examined by SEM, and FTIR. Ceramics made from Silres 610/rice bran 50/50 ratio showed the highest compressive strength (2.7 MPa) along with the highest ceramic yield (47.8%), but the lowest hygroscopic expansion, and volume shrinkage. On the other hand, the 20/80 ratio showed the lowest ceramic yield and compressive strength but the volume shrinkage higher than the 50/50 ratio. All ceramics showed negligible hygroscopic expansion.

We have prepared a series of platinum complexes with a rodlike ligand and smectic (Sm) liquid crystals (LCs) to demonstrate polarized phosphorescence. The ligands for the Pt complexes “12F2PPyO8” [2-(4′-dodecyl-5′,6′-difluorophenyl)-5-octyloxypyridinato-N,C2′] and “12F2PPyO12” [2-(4′-dodecyl-5′,6′-difluorophenyl)-5-dodecyloxypyridinato-N,C2′] with long alkyl and alkoxy chains exhibited the Smectic A (SmA) phase, however no liquid crystallinity was evident in Pt complexes with LC ligands. The host LCs 1-(4-butyl-2,3-difluoro-phenyl)-4-(trans-4-pentylcyclohexyl)benzene (4F2PPCH5) and 2-(2,3-difluoro-4-hexylphenyl)-6-octyloxynaphthalene (6F2PNaO8) with long flexible chains showed wide SmA phase temperature ranges. Pt complex/Sm LC mixtures were oriented on rubbed polyimide substrates or by applying a magnetic field. The orientation coefficients of the magneto-oriented samples were recorded to be over 0.6 in the Sm LC temperature range. The oriented samples exhibited polarized optical emissions assigned to the monomer and excimer states, which were perpendicular to the orientation direction. This indicates that the transition dipole moment of the Pt complex is oriented from the ligand to the Pt atom. Pt complexes with rodlike ligands with long alkyl and alkoxy chains and host Sm LC with such chains are much more likely to obtain high order parameters and generate highly polarized optical emissions. In the mixtures, the polarization ratios of the monomer and excimer in the SmA phase were estimated to be approximately 2.5–2.9 and 4.6–5.4, respectively.

Rice bran (RB), rich in carbon and silicone, is an agricultural waste that is abundantly available in rice producing countries. In this work, composites of a preceramic methyl silicone resin (MSR) and RB were prepared by blending powdered RB with a molten MSR at 110 °C at various ratios in a Brabender-type static mixer. Composites were made from them by compression molding and cross-linking at 260 °C under 20 MPa pressure. The thermal, mechanical, and chemical properties of the produced composites were assessed by thermogravimetric analysis, scanning electron microscopy, and FT-IR and by measuring compressive strength and hygroscopic expansion. It was found that RB was partially ceramized and decomposed to carbonaceous materials during cross-linking. The water absorption and hygroscopic expansion of the MSR/RB composites were increased but the compressive strength was decreased with an increase in the weight % of RB. The highest compressive strength was shown by the composites made from the 50/50 blends, ...

Nematic liquid crystals (LCs) dropped via micro-dispenser (3 μL) on a vertical alignment (VA) polyimide coated indium tin oxide glass substrate have been observed under crossed polarisers. The wettability between the LC and the VA polyimide layer was extremely low. The contact angle of the LC droplet was around 33° and the droplet diameter was much smaller than the LC on the parallel-aligned polyimide layer. The contact angle of the droplet increased, and the droplet diameter decreased, on increasing the molar fraction of the side group of the polyimide. The flow behaviour of the LC by assembling between the two substrates has been directly observed under crossed polarisers. The droplet spread out keeping a cross-extinction pattern during assembling. After assembling to a 5 μm gap, a dark field was observed in whole area on the polyimide alignment layer with 50 mol% side group. Increasing the side group enhanced aligning the LC perpendicular to the substrate, and no disclination appeared.

The influence of temperature during reactive extrusion of poly(L-lactide) (PLLA) on the molecular architecture and crystallization behavior was investigated for OO-(t-butyl) O-(2-ethylhexyl) peroxycarbonate-modified polymer. The long chain–branched PLLA (LCB-PLLA) content and its structure in the resulting slightly crosslinked PLLA (χ-PLLA) containing linear and LCB-PLLA were characterized by both analyses, size exclusion chromatography equipped with multiangle laser light scattering and rheological measurements. A reduction of LCB-PLLA content in χ-PLLA and an increase of number of branches in LCB-PLLA were found with increasing the extrusion temperature. An increase of extrusion temperature induces different process in the polymer: decrease of the lifetime of peroxide, increase of the radical concentration due to rapid peroxide decomposition rate, and increase of the chain diffusion to the amorphous phase. Among these indices, the lifetime of peroxide is a good index for crosslinking behavior of PLLA during extrusion. As for the isothermal crystallization behavior from the melt, the Avrami crystallization rate constant of χ-PLLA increases as an increase of LCB-PLLA content in χ-PLLA. This implies that LCB-PLLA acts as a nucleating agent for PLLA. Furthermore, regime analysis and the free energy of nucleus of χ-PLLA were investigated using Hoffman–Lauritzen theory. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Electrically conducting samples of polyaniline (PANI) were prepared by doping with dodecylbenzene sulfonic acid (DBSA) using a thermal doping method without the application of shear. Besides characterizing the samples using optical microscopy, SEM, UV-vis-NIR, the degree of doping and the electrical conductivity were also measured. The pure PANI powder consisted of aggregates of PANI particles and was non-conducting. In the shear-free thermal doping of the PANI/DBSA mixture, the original aggregates were progressively broken up into smaller pieces with increasing temperature while maintaining the original primary particle shape and size and which were dispersed rather uniformly in the DBSA matrix. The electrical conductivity of doped PANI increased with increasing doping temperature. This increase strongly mirrored the increase in the levels of DBSA directly associated with PANI and suggested that the increasing levels of PANI doping were directly responsible for the increase in electrical conductivity as a function of the doping temperature. Despite the absence of the absorption peak at around 800 nm, the sample absorbed strongly in the near-infrared. Moreover, PANI/DBSA samples possessing a higher ratio of absorbance at 2600 nm to that at 800 nm showed higher electrical conductivity. These results suggest that shear-free thermal doping provides a simple route to controlling the morphology of the mixture by enabling the disintegration of the micron scale aggregates present in the as-purchased PANI. This in turn can be used to control the degree of doping of the PANI and consequently the conductivity of the sample. Copyright © 2011 John Wiley & Sons, Ltd.

Ethene-/α-olefin copolymers having a wide range of comonomers between 8 and 26 carbon atoms in length were characterized by wide angle X-ray diffraction (WAXD). It was found that the crystallinities for the shorter comonomers (C8, C12) matched fairly well with the crystallinities from DSC and volumetric measurements, while for the longer comonomers (C18, C26) distinct differences between the three methods were found. This was explained by the presence of an additional crystalline phase of the side chains slightly deforming the amorphous peak.

Reactive extrusion of poly(L-latctide) (PLLA) was carried out in the presence of a small amount of various peroxides. The resulting crosslinked, four-armed randomly branched PLLA (χ-PLLA) was characterized by size exclusion chromatography fitted with multiangle laser light scattering and rationalized with the type of peroxide used. The extent of branching of χ-PLLA was estimated by the shrinking factor and was rationalized with the effective radical number per PLLA precursor n. The nucleation and overall crystallization rate of χ-PLLA in the nonisothermal crystallization from the melt was rationalized with branching and entanglement density.

Fabrication of CNT-dispersed epoxy under various conditions using the ball milling process is performed as a fundamental research on the application of CNT-dispersed resin to CFRP composites. CNT length in compounds and viscosity of CNT-dispersed resin are measured in relation to process conditions. Viscosity characteristics on CNT-dispersed compounds and relationship between CNT length and viscosity are clarified in this paper.

Several techniques are introduced to enhance the interlaminar fracture toughness of CFRP laminates using cup-stacked carbon nanotubes (CSCNTs). Prepared CSCNT-dispersed CFRP laminates are subject to Double Cantilever Beam (DCB) and End Notched Flexure (ENF) tests in order to obtain mode-I and mode-II interlaminar fracture toughness. The measured fracture toughnesses are compared to that of CFRP laminates without CSCNT to evaluate the effectiveness of CSCNT dispersion for the improvement of fracture toughness. All CSCNT-dispersed CFRP laminates exhibit higher fracture toughness, and specifically, CSCNT-dispersed CFRP laminates with thin epoxy interlayers containing short CSCNTs have three times higher fracture toughness than CFRP laminates without CSCNT. SEM observation of fracture surfaces is also conducted to investigate the mechanisms of fracture toughness improvement. Crack deflection mechanism is recognized in the CSCNT-dispersed CFRP laminates, which is considered to contribute the enhancement of interlaminar fracture toughness.

Poly( l -lactide) (PLLA) was cross-linked with various types of peroxides under constant mole ratios of peroxide-derived radicals to PLLA during reactive extrusion. Peroxides were classified into three groups according to their decomposition rates (Group I: fast, Group II: moderate and Group III: slow) and comparisons were performed within each group. Cross-linking behavior was readily understood in terms of free radical efficiency and hydrogen abstraction ability of radicals. In the case of Groups II and III, the weight-average molecular weight ( M w ) of cross-linked PLLA increased with overall hydrogen abstraction ability, because slow decomposition caused uniform cross-linking in molten PLLA. In Group I, M w and gel fraction were higher than other groups despite Group I's lower hydrogen abstraction ability, leading to the conclusion that peroxide decomposition localized in solid PLLA caused partial cross-linking because of rapid decomposition. Furthermore, the efficiency of peroxide-induced cross-linking was investigated using the Charlesby–Pinner equation.

Vapor-grown carbon fiber (VGCF)/silicon oxycarbide ceramic composites have been prepared by pyrolysis of a VGCF/methylsilicone precursor (MSR) composite produced through polymer melt-mixing. The electrical resistivity of the composite before and after pyrolysis was drastically reduced by VGCF (above 5 wt% in MSR), and reached the order of 100 Ω cm. However, the ceramic composite could not always maintain its shape because of shrinkage from the weight loss of MSR during pyrolysis. To overcome this difficulty, polymethyl methacrylate (PMMA) microbeads were added as a sacrificial processing aid during melt-mixing to enable the material to maintain its shape through the microporous structure generated. The microcellular VGCF/ceramics obtained from VGCF/MSR/PMMA were characterized in terms of their shrinkage, mechanical, structural and electrical properties, and their composition was optimized. It was found that microcellular VGCF/ceramics derived from an optimal VGCF/MSR/PMMA composition of 5/45/45 (by weight) gave a low electrical volume resistivity (around 1.0 Ω cm), comparable to that of VGCF/ceramics from 10/90 (by weight) VGCF/MSR.

The influence of filler types and concentration on the foaming structure was investigated using a batch method to penetrate CO2 in ABS polymer matrix. Vapor grown carbon fiber (VGCF®, averaged diameter = 150 nm), and calcium carbonate (averaged particle diameter = 1.8 μm) were used as fillers and the concentration was changed from 5 to 15 wt %, respectively. Vapor grown carbon fiber or calcium carbonate was compounded with ABS using an extruder and samples were made by hot press method. Foamed samples, whose density reduction showed about 30–40%, were made by controlling preparation conditions.In the case of vapor grown carbon fiber/ABS systems, the average diameter of foaming cell decreased, and the cell density increased as a function of fiber concentration. On the other hand, by the incorporation of calcium carbonate, the diameter increased, and density decreased with higher concentration. The initial nucleation stages of foaming from fillers were carefully observed for fillers having large aspect ratio and particle shape. Based on the evidences from optical microscope observation, the different tendency of cell diameter between the two systems as a function of concentration was discussed.

A facile method of simultaneous alignment and micropatterning of multi-wall carbon nanotubes (MWCNTs) is presented. The method uses the combination of the magnetic alignment and patterning techniques. Due to their diamagnetic nature, MWCNTs suspended in a liquid medium are trapped at the minima of the magnetic field created by a field modulator and at the same time they align due to their magnetic anisotropy. The achieved patterning and alignment is fixed by solidification of the matrix. The alignments both parallel and perpendicular to the film surface have been achieved.

A trace amount of vapor-grown carbon fibers (VGCFs) were dispersed in polydimethylsiloxane (0.097 Pa s) by mechanical stirring. A magnetic field (0.23 T) was applied to the dispersion while in situ optical microscope observation was performed. The alignment rate was determined through analysis of the VGCF orientation. Using this suspension method, the diamagnetic anisotropic susceptibility of VGCF was estimated to be 3.11 × 10 −4 (–). From this value, the alignment time of VGCFs was estimated as a function of viscosity or magnetic field. The anisotropic susceptibility of VGCFs was compared with those of conventional carbon fibers.

紫外線硬化型高分子液体中で Vapor-Grown Carbon Fiber(VGCF®)の分散状態が異なる分散液を調整し，複合体フィルムを作製した．一つは紫外線硬化型高分子液体に VGCF®を均一分散させた．もう一つは前者に熱処理し，VGCF®のネットワーク構造を誘起させた．これら 2 種の分散液に磁場(1 T, 10 T)を膜厚方向に印加した．VGCF®が均一分散した系に磁場印加した場合，均一分散状態で磁場方向に配向した(1 T, 10 T ともに同じ配向構造)．一方，VGCF®ネットワーク構造を有した系に磁場印加した場合，ネットワーク構造を保持し，磁場方向に配向した．特に 10 T の方が高度に配向した．また，VGCF® 1.0 wt%が均一分散した膜厚方向の体積抵抗率は磁場印加前後で変化なく 1010 Ω・cm 以上であった．一方，ネットワーク構造を有するフィルムは磁場無印加，1 T, 10 T でそれぞれ 4.2×105 Ω・cm, 2.1×105 Ω・cm, 9.6×103 Ω・cm と抵抗率が減少した．