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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.

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.

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.

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.).

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.

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.

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.

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．

Microcellular silicon oxycarbides have been produced by pyrolysis of methylsilicone resin with the help of sacrificial microbeads of polymethyl methacrylate (PMMA). The PMMA microbeads were added in the range from 0 to 80 wt%, and the pyrolysis was performed at 800–1200 °C. The volume shrinkage resulting from the polymer-to-ceramic conversion becomes constant at the pyrolysis temperature above 1000 °C, and the shrinkage value reaches about 60% by a PMMA addition of 80 wt%. In the all range of PMMA additive ratios, the spherical micro pores with the wide range diameter from 1 to 10 μm are produced in the matrix. The open-cells, which are formed above 30 wt% of PMMA addition, have the open pores size bigger than 0.5 μm. The bending strength and the elastic modulus of the product exhibit the maximum values, i.e., 24.1 MPa and 16.0 GPa, respectively, when PMMA addition is 50 wt%.

Vapor-grown carbon fibers (VGCFs) have outstanding mechanical, thermal, and electric characteristics, and it has strong anisotropy. To take advantage of the enhanced properties, the orientation control of VGCFs should be important. In recent years, the orientational control of VGCFs by magnetic processing has received considerable attention. We have performed the magnetic processing of polymer composite films including VGCFs by using magnetic processing apparatus with permanent magnets (1 T) and superconductive magnet (10 T). We have studied the orientation of VGCFs along the thick-ness direction of the film. It was demonstrated that the oriented VGCFs/polymer composite films were successfully produced even by permanent magnets (1 T). The volume resistivity (Ω·cm) of the film (vertically oriented VGCFs, 1.0 wt %, 10 lim thickness) showed 3.2 × 1012 and 2.1 × 100 Ω·cm along surface and thickness direction, respectively. Vertically oriented VGCFs / polymer composite film could be utilized as an alternative material having anisotropic electric conductive property.

Uniaxial elongational flow behavior was examined for polystyrene(PS)/styrene-butadiene-styrene(SBS) triblock copolymer by using a Meissner type rheometer under uniaxial elongational flow at constant strain rates. The mixtures of PS and SBS were prepared by means of a solution blending method. Pure PS did not exhibit strain-hardening. Elongational viscosity was quite similar among the mixtures of PS/SBS without heat treatment. However, large enhancement of strain-hardening was observed for PS/SBS blends treated at temperatures higher than 220 °C, and the magnitude of enhancement reached ten times or more. To analyze the cause of the enhancement of strain-hardening, we examined pure SBS itself using a combination of uniaxial elongation and FT-IR spectroscopy. Change in uniaxial elongational flow behavior, i.e., from strain-softening to strain-hardening, was observed corresponding to heat treatment temperatures. From FT-IR spectroscopy of SBS treated at various temperatures, the correlation between enhancement of strain-hardening and crosslinking of butadiene was obtained. From shear stress relaxation measurement of PS/SBS(90/ 10) treated at 260 °C for 60 min, convergence of relaxation modulus was observed in a strain range of γ 2 at long times. Thus, the increase of strain-hardening of PS/SBS blends treated at high temperatures is likely to result from affine deformation of crosslinked SBS component.

We have tried to form a variety of oriented structures in liquid crystalline materials and composites by magneto-processing. Using photo-curable liquid crystal (LC), homogeneous, homeotropic, and bend oriented structures were fixed in the films. Moreover, UV light was irradiated to the LC monomers through a photomask under the magnetic field. The pattern was successfully recorded in the film by molecular orientation. Low viscous branched LC molecules, LCs based on calix [4] resorcinarene and dendrimer, synthesized in this study could be highly aligned under the magnetic fields. The smectic structures of these LC materials were demonstrated from X-ray diffraction results of the magneto-oriented samples. Carbon nanotubes (CNTs) were aligned parallel to the field direction in polycarbonate (PC). Moreover, magneto-oriented CNTs remarkably enhanced the recrystallization of the PC during annealing.

Carbon nanotube (CNT) /polymer composites have been expected for a promising application of CNT and have received considerable attention in fundamental studies. Recent progress of Carbon nanotube/polymer composites is reviewed from polymer material point of view for utilizing CNTs into polymer matrix.

It is known that polycarbonate (PC) is categorized as amorphous polymer and pure PC crystallizes extremely slowly. However, we have recently found that the crystallization of PC was substantially accelerated around 200 °C in the presence of vapor grown carbon fiber (VGCF), having ultra thick multi-walled carbon nanotube (MWCNT) structure. To examine the accelerated crystallization by VGCF, the effect of pre-graphitized VGCF, carbon black, and mesophase pitch based carbon fiber (CF) on the crystallization was evaluated. In addition, polarized optical microscope observation was performed by using PC including magnetically oriented VGCF. It was suggested that the surface of ordered graphite structure from VGCF or CF induced the oriented crystallization of PC along the axial direction of VGCF or CF. To utilize the accelerated oriented crystallization of PC by CF, PC sheet having oriented crystallized surface PC layer was made by annealing the stacked structure of PC sheet and oriented CF sheet at 200 °C. The PC sheet, whose surface was crystallized along CF axial direction, was successfully produced, showing retardation property by polarized optical microscope.

A novel polystyrene(PS) with an incorporation of a small mass fraction of styrene-butadine-styrene(SBS) and dicumyl peroxide(DCP) has been developed to enhance strain-hardening significantly under elongational flow. Here, strain-hardening is defined as steep increase of elongational viscosity at large strain which deviates from linear viscoelastic curve. The content of SBS was in a range from 1wt% to 10wt%, and the content of DCP was in a range from 0.01wt% to 0.1wt%. Pure PS at 180 °C did not exhibit any strain-hardening. Whereas, significant enhancement of strain-hardening was observed for PS blended only 1wt% SBS and 0.1wt% DCP. The magnitude of strain-hardening (SH) was over 10 up to Hencky strain of 3. Note that the parameter, SH, is defined as elongational viscosity at large strain to linear viscoelastic envelope at the same time. Enhancement of strain-hardening was in the order of SBS content and DCP content. The magnitude of strain-hardening(SH) for PS/SBS/DCP(SH~70 at the maximum) was much more remarkable than that of any other PS such as PS/UHMW-PS and branched PS reported before(SH

Carbon fiber (CF) has outstanding mechanical, thermal, and electric characteristics, and it has strong anisotropy. To take advantage of the enhanced properties, the orientation control of CFs should be important. In recent years, the aligned carbon nanotube (CNT) /polymer composites have been produced by the application of high magnetic field. However, there are few reports about magnetically oriented CF/polymer composites. We have performed the magnetic processing of polymer composite films including CFs by using our magnetic processing machine (0.9 T) with permanent magnets, and a commercially available superconductive magnet (10 T). We have studied the orientation of CFs along the thickness direction of the film. The orientational distribution of CFs was analyzed by three dimensional optical microscope analysis in addition to X-ray diffraction. It was demonstrated that the oriented CF/polymer composite films were produced even by permanent magnets. The electric resistance of the film (vertically oriented CFs, 10wt.%), after magnetic processing (0.9T), was improved by the order of 109Ω·cm. It was also found that the film showed anisotropic electric property.

A novel method to make a porous material having relatively large cell diameter (200–300 μm), which consisted of mainly poly(tetrafluoroethylene) (PTFE), was developed from aqueous PTFE dispersion by using the characteristics of hydrogel with the addition of carbon nanofiber (CNF). The porous material was produced as follows: firstly, an aqueous agar gel containing PTFE and CNF was prepared; secondly, the gel was freeze-dried; thirdly, the dried gel was heat-treated at 400°C where the agar was almost decomposed and PTFE became molten. The porous material showed electric conductivity (about 50 Ω), high porosity (about 96 vol%), and relatively uniform cell structures without shrinkage during freeze drying and heat treatment. While the method without CNF resulted in large shrinkage during heat treatment, meaning that CNF prevented the shrinkage. It was explained by the idea that the existence of rigid CNF, which was dispersed in the cell wall, prohibited the shrinkage of PTFE during heat treatment. It was unexpectedly found by SEM analysis that the porous materials had another macro-porous structure inside the cell wall, suggesting that the developed materials had a double porous structure.

The enhancement of tensile strength and elongation of poly(L-lactic acid) without using additives has been awaited to open new environmentally friendly markets. To improve the brittle mechanical properties of poly(L-lactic acid), we have investigated the effect of draw ratios and process temperatures on the mechanical properties. The results suggested that tensile strength linearly increased as a function of draw ratio, but elongation at break had a maximum value around draw ratio 2. It was found that the mechanical properties of the films were strongly affected by the draw ratio and not by the process temperature. Δn increased as a function of draw ratio up to 4 (the highest limit of the present test). These results allowed us to interpret that the mechanical properties reflected mainly molecular orientations in the amorphous regions, which were governed by the draw ratio.

結晶相が存在し, 非晶相が相溶している, ポリメチルメタクリレート (PMMA) とフッ化ビニリデン-三フッ化エチレン共重合体P (VDF-TrFE) とのブレンド (20/80重量比) について, 熱刺激脱分極電流測定 (TSDC) およびサーマルサンプリング熱刺激脱分極電流測定 (TS-TSDC) をおこなった. このブレンドは, -50から80℃の範囲においてTSDCグローバルスペクトルで-30と60℃付近にわずかなピークが観測できた. しかし, TS-TSDCスペクトルではこれに加えて15℃付近にもピークが観測された. さらに, TS-TSDCスペクトルから計算した活性化エネルギーの温度依存性で-30と15℃にショルダーと, 60℃にピークが観測された. これらから非晶相は相溶 (TSDC, TS-TSDCでの60℃のピーク) しているものの, P (VDF-TrFE) のみの非晶相もわずかに存在する (TSDCでは検出できないがTS-TSDCでの15℃のピーク) ことがわかった. 感度の良好なTS-TSDC測定手法とその解析をすることで, ブレンド中の構造を議論できることを示した.

気相成長炭素繊維 (Vapor-grown Carbon Fiber, VGCF) を簡便な方法で分散させる方法を見いだし, これを用いて今まで報告のほとんどない混合前後におけるVGCFの長さ変化を測定した. ここではVGCF (昭和電工 (株) 製) を用いて, かさ密度を大きくする処理をしたVGCF, ポリカーボネートと溶融混合したVGCFの長さ測定をSEM観察により行った. VGCFはかさ密度を大きくする処理過程や溶融混合過程において切断され, 平均長さはそれぞれ6.7μmから3.9μm, 3.0μmとなったことを本研究で明らかにした

Biodegradable Poly (L-lactic acid) [PLLA]/Poly (bu-tylenes succinate) [PBS] or PLLA/Poly (butylenes succinate adipate) [PBSA] blend films were prepared. We have investigated the thermal and mechanical properties of the resulting films by using dynamic mechanical analysis, differential scanning calorimetry (DSC), tensile properties and morphological analysis. The experimental dynamic mechanical results suggested that blending of PBS or PBSA into PLLA caused an increase of the storage modulus (E') as a result of the crystallization of PLLA. From the DSC results, it was also demonstrated that the crystallization of PLLA was accelerated by blending it with PBS or PBSA. An improvement in the mechanical properties was observed by blending PLLA with PBS or PBSA. This improvement was believed to be due to the PBS or PBSA becoming the matrix in the blended films.