Hideaki Hagihara

National Institute of Advanced Industrial Science and Technology

The study develops an oxidative kinetic model of acrylic‐urethane network during photo‐aging. The kinetic model can track chemical reaction dynamics well and also enables to estimate the network lifetime by counting scission/crosslinking events. Estimated network lifetime is semiquantitively coincided with the one derived from different statistical...

In this study, a new system was developed to carry out simultaneous near-infrared (NIR) and small-angle X-ray scattering (SAXS) measurements. Aged PP was examined with the NIR-SAXS system to demonstrate how it can be utilized to derive pertinent information about polymer structure. Pairs of SAXS profiles and NIR spectra of PP in its initial state a...

This study introduces a novel method that utilizes evolved gas analysis with time-of-flight mass spectrometry (EGA-TOFMS) coupled with principal component analysis (PCA) and Kendrick mass defect (KMD) analysis, called EGA-PCA-KMD, to analyze complex structural changes in polymer materials during thermo-oxidative degradation. While EGA-TOFMS capture...

A novel technique, in-situ infrared (IR) cure monitoring coupled with two-trace two-dimensional (2T2D) correlation analysis, is developed to probe the property-enhancement mechanism of a newly developed thermosetting nanocomposite comprising an acrylic-urethane network (AUN) and silica nanospheres (SNS). The IR spectra were collected in real-time d...

This study addresses the multiscale analysis of acrylic urethane networks (AUN). To establish the kinetic model for predicting AUN oxidation, this study considered the pure thermal oxidation of AUN at 160, 180, and 200 °C. Chemical changes were monitored using infrared spectroscopy. These indicated the presence of an imide, presumably generated fro...

The molecular-scale deformation behavior of glass-fiber-reinforced polypropylene was probed by a newly developed rheo-optical Fourier transform infrared (FTIR) imaging technique combined with two-trace two-dimensional correlation mapping. This technique, based on an in situ polarized FTIR microscopic analysis, revealed variations in the polymer ori...

To get insights into the excellent gas-barrier properties of amorphous polyamide m-xylylenediamine-adipic acid-isophthalic acid copolymer (MXD6I), free-volume hole size and thermophysical properties of MXD6I were evaluated. The results from positron annihilation lifetime spectroscopy (PALS) showed that the free-volume hole size of MXD6I—which was e...

We have developed a three-way evolved gas analysis-mass spectrometry technique combined with principal component analysis (EGA-MS-PCA) to probe the interfacial state between matrix and filler in poly(styrene-b-butadiene-b-styrene) (SBS) nanocomposites containing graphene nanoplatelets (GNPs). Although the peaks arising from the polystyrene and poly...

This paper describes the first in-depth attempt to characterize thermally induced aging of polypropylene (PP) samples by near infrared (NIR) spectroscopy. Significant levels of variation in NIR bands associated with short (amorphous-dominated) and long (crystalline-dominated) helices was readily captured when PP samples were subjected to thermal ag...

A technique for analyzing IR imaging data based on two-trace two-dimensional (2T2D) correlation analysis is presented to extract pertinent information underlying spectroscopic imaging data. In 2T2D correlation mapping, each spectrum in hyperspectral data is individually compared with a reference spectrum to generate 2T2D asynchronous correlation in...

In this work, the role of moisture in photo-ageing was discussed for the case of an acrylic-urethane network. Ageing behaviours were characterised by Fourier transform infra-red spectroscopy, positron annihilation lifetime spectroscopy, sol-gel analysis, and differential scanning calorimetry. Two common features between dry and wet photo-ageing, na...

We have developed a novel rheo-optical Fourier transform infrared (FTIR) imaging technique that can probe the molecular-scale deformation behavior of polymer matrix in composite materials. This rheo-optical FTIR imaging is based on in situ polarized FTIR imaging of a polymer sample while it is being deformed by mechanical force. This imaging techni...

We propose a technique for evaluating the compatibilization effect of maleic anhydride-grafted polypropylene (MAPP) introduced into glass fiber reinforced polypropylene by probing chemical structures using Fourier transform infrared (FTIR) microscopy. The dispersion state of MAPP in the composites was investigated by FTIR imaging constructed with i...

Simultaneous improvement in the mechanical properties and lifetime of polymer nanocomposites is crucially significant to further extend the versatility of polymer materials and reduce environmental impact. In this study, we fabricated reinforced polypropylene (PP)-based nanocomposites with improved aging stability by the addition of surface-modifie...

Submolecular-level variation of polypropylene (PP) caused by aging treatment is studied by two-dimensional (2D) small-angle X-ray scattering (SAXS) in conjunction with 2D correlation spectroscopy. PP samples were prepared by a T-die extrusion method and then probed by 2D SAXS. Direction-depending SAXS profile data were obtained by extrusion the SAX...

Structural changes induced by photo-aging have significant influence on material properties. The prediction of the period prior to the onset of significant morphological changes is useful in determining material service lifetime. We assume “degelation” to be the starting point of significant morphological change during photo-aging. Herein, we demon...

We demonstrate a Fourier transform infrared (FTIR) spectroscopic imaging combined with two-dimensional (2D) correlation analysis to elucidate matrix-filler interaction of polymer composites. Composite of maleic anhydride grafted polypropylene (MAPP) and silica sphere (SS) was fabricated. The FTIR image and disrelation map derived from sets of FTIR...

The structural alteration of acrylic-urethane coatings, induced by photo-aging, and its temperature dependence, was investigated using positron annihilation lifetime spectroscopy and solvent swelling experiments. The results revealed a slight structural alteration due to photo-aging at 20 °C. On the other hand, a significant structural alteration o...

The generation of acetic acid from the ethylene vinyl acetate (EVA) encapsulant in crystalline Si photovoltaic (PV) modules was investigated by free-volume analysis with positron annihilation lifetime spectroscopy (PALS). The reduction in size of a free-volume hole attributable to deacetylation was clearly observed near the surface of the EVA encap...

Nanocomposites containing mesoporous silica (MPS) materials with various pore structures (SBA-15 and MCM-41 types) melt mixed into polypropylene (PP) or PP functionalized with hydroxyl groups (PPOH) were characterized by analytical pyrolysis techniques, such as evolved gas analysis (EGA)-mass spectrometry (MS) and heart-cut EGA-gas chromatography (...

The long-range objective of this study is to provide better understanding of the relationship between the structures and properties of PP-based nanocomposites containing mesoporous silica (MPS). In this investigation, nanocomposites composed of MPSs with various porosity structures (two types of Santa Barbara Amorphous No. 15 (SBA-15) with pores of...

Degradation testing of nylon 6-based carbon fiber-reinforced thermoplastic (CFRTP) was performed by exposure to hot steam in a closed vessel. The degraded structure was investigated to understand the degradation mechanism. Aging-induced micro-cracking in the nylon 6 matrix of CFRTP indicated that internal stress was generated by changes in its loca...

We developed novel polypropylene (PP)/silica nanocomposites using PP and silica nanospheres (SNSs) combined with poly(5-hexen-1-ol-co-propylene) (PPOH), which is a functionalized PP containing hydroxyl groups that was assumed to play a role as not only an elastomer but also an interface modifier. Since the affinity between the PP matrix and silica...

Functionalized polypropylene with hydroxyl group (PPOH) nanocomposites with varying chemical structures in filler-matrix interfaces were examined by rheo-optical near-infrared measurements combined with two-dimensional correlation spectroscopy, to provide a better understanding of the reinforcement mechanism of nanocomposites. PPOH nanocomposites w...

The structure of ethylene vinyl acetate (EVA) encapsulants of crystalline-Si photovoltaic modules after the damp heat (DH) test was evaluated by positron annihilation lifetime spectroscopy (PALS). A reduction in free-volume hole size, which indicates the progress of deacetylation, was observed after the DH test. The difference in lifetime between t...

A quick method involving the control of heat and water vapor pressure for preparing moisture-saturated carbon fiber-reinforced plastics (CFRP, 8 unidirectional prepreg layers, 1.5 mm thickness, epoxy resin) has been developed. The moisture-saturated CFRP sample was obtained at 120 °C and 0.2 MPa water vapor in 72 h by this method using a sterilizer...

We fabricated nanocomposites by dispersing uniform-sized silica nanospheres (SNSs, 49–282 nm, 0–30 wt%) into polypropylene (PP) and two types of functionalized PP to clarify the effects of matrix-filler interfacial adhesion forces on the mechanical properties in PP-based nanocomposites. Since there is good affinity between silica surfaces and hydro...

ROOH was a key intermediate compound in oxidation of polymer because it was only source of ·OH radicals. ROOH was believed to be produced by ROO⋅ abstraction H-atom from polymer, which is thermodynamically unfavorable, but it may be facilitated due to the high polymer concentration. However, ROOH also could be produced by ROO· reaction with HO2·. F...

PET films were degraded at temperature higher than 100°C with steam and xenon light by using the newly developed system. Degradation products obtained using the proposed and conventional systems were essentially the same, as indicated by the similar increase in the intensity of the carbonyl peak near 1685 cm −1 in the FT-IR spectra of irradiated sp...

Positron annihilation (PA) has been documented as a powerful tool for evaluating molecular-level open spaces in various materials such as semiconductors, gas sensors and separation membranes. There are several advantages of PA over other methods; it is nondestructive, sensitive to holes/pores (of 0.3 nm～50 nm in size) irrespective of either open or...

Application of the two-dimensional (2D) correlation spectroscopy is extended to Chemiluminescence (CL) spectra of isotactic polypropylene (iPP) under thermally induced oxidation. Upon heating, the polymer chains of the iPP undergoes scissoring and fragmentation to develop several intermediates. While different chemical species provides the emission...

Two fulleropyrrolidine derivatives with benzophenone moiety were synthesized based on a molecular design that suppresses crystallization of the fullerene derivatives. The organic photovoltaic devices using the fulleropyrrolidine derivatives showed higher thermal stability in comparison with the devices using [6,6]-phenyl C61-butyric acid methyl est...

The degradation of poly(ethylene terephthalate) (PET) was investigated through a weathering test by using a xenon weather meter. The degraded structure was evaluated by means of gel permeation chromatography (GPC), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and positron annihilation lifetime spectroscopy (PALS). The...

Two types of commercial cellulose triacetate hollow-fiber membranes with different water fluxes, apposite for a reverse osmosis separation process, were investigated by means of positron annihilation lifetime spectroscopy with a Na-22-radioisotope-based energy-tunable positron beam, in order to elucidate a depth profile of the free-volume hole size...

Polypropylene (PP) and its derivatives, poly(5-hexen-1-ol-co-propylene) (PPOH) and poly(1-hexene-co-propylene) (PPH), were comprehensively investigated by means of wide-angle X-ray diffraction, dynamic mechanical analysis (DMA), 1H pulsed nuclear magnetic resonance (NMR), infrared (IR), and positron annihilation lifetime (PAL) techniques. The deduc...

We studied chemiluminescence spectroscopy to develop an evaluation method for organic material degradation. The thermal oxidation of oleic acid as a monounsaturated fatty acid was investigated using chemiluminescence measurements. The obtained spectra indicated that the luminescence consisted of several peaks, including peaks for singlet oxygen and...

Thanks to excellent cost performance, easy to mold, light weight (low density) and so on, we can see polypropylene everywhere as wide application, so polypropylene is the one of the most familiar material in all kind of polymers. In this paper, current situation of polypropylene in world market as well as of history and current movement in R&D were...

Polypropylene (PP) derivatives, prepared with different α-olefin comonomers of hexane and hexenol, were investigated using the positron annihilation lifetime technique. The free-volume hole sizes for the present polymers were quantified from the long-lived ortho-positronium (o-Ps) lifetimes. In contrast to the case of nonpolar, introduction of the...

We describe the synthesis of a styrene–ethylene copolymer using a trivalent titanium-based polymerization catalyst system, tris(acetylacetonate)titanium (Ti(acac)3), combined with triisobutylaluminum-modified methylaluminoxane. Gel-permeation chromatography measurement revealed that copolymerization using the above-mentioned catalyst system yielded...

This article reports the synthesis and characterization of an extremely high thermostable cyclic olefin copolymer with advanced optical properties resulting from the vinyl addition copolymerization of norbornene with styrene catalyzed by a substituted fluorenylamidodimethyltitanium catalyst [Me(2)Si(3,6-tBu(2)Flu)(tBuN)]TiMe(2) activated with a [Ph...

Additive effects of diisobutylaluminum hydride (DiBAL-H) was studied in copolymerization of propylene and 1,3-butadiene with a series of C2-symmetric ansa-bis(indenyl)zirconocene derivatives, i.e., rac-dimethylsilylbis(2-methyl-4-phenylindenyl)zirconium dichloride (4Ph), dichloride, rac-dimethylsilylbis(2-methyl-benzoindenyl)zirconium dichloride (B...

Styrene polymerization was carried out by a simple half-titanocene complex [cyclopentadienyltitanium trichloride] (CpTiCl3) and pentamethyl [cyclopentadienyltitanium trichloride] (Cp*TiCl3) combined with methylaluminoxane (MAO) as a cocatalyst. The effects of addition of 2,6-diisopropylphenol on the catalytic activity of the above catalytic systems...

Study of mechanical properties of the functionalized polypropylene (PP) containing a hydroxyl group (PPOH), which revealed new relation of elastic modulus and impact strength, was reported. It was observed that hydroxyl group incorporated copolymers showed a higher toughness strength compare to both pure PP and copolymer without a hydroxyl group. I...

Styrene polymerization was carried out by a simple half-titanocene complex [cyclopentadienyltitanium trichloride] (CpTiCl3) and pentamethyl [cyclopentadienyltitanium trichloride] (Cp*TiCl3) combined with methylaluminoxane (MAO) as a cocatalyst. The effects of addition of 2,6-diisopropylphenol on the catalytic activity of the above catalytic systems...

This article reports an original method to control the birefringent property of the cyclic olefin copolymer, which has been recently commercialized as a new type of optical resins, via introduction of a third monomer that possesses a negative birefringence into the cyclic olefin copolymer that exhibits an inherently positive birefringence. The mutu...

We inclusively investigated polymerization behavior and structure of co-polymer in the copolymerization of propylene and alkylaluminum-protected polar allyl monomers. The control of the arrangement of polar group in the copolymer was discussed. It was proved that the location of polar group could be controlled by zirconocene catalyst and a kind of...

Poly(propylene-ran-1,3-butadiene) was synthesized using isospecific zirconocene catalysts and converted to telechelic isotactic polypropylene by metathesis degradation with ethylene. The copolymers obtained with isospecific C-2-symmetric zirconocene catalysts activated with modified methylaluminoxane (MMAO) had 1,4inserted butadiene units (1,4-BD)...

The packing structures or the local packing disorders included in iP3M1B polymer crystal through the resolved nuclear magnetic resonance (NMR) signals were investigated. Two-dimensional (2D) refocused technique through J-mediated interaction and two-phase pulse modulated decoupling to the iP3M1B crystal at a low temperature of 233K were applied. Th...

The microstructural analysis of insoluble polyolefins was analyzed at very high temperatures by using melt-state 13C NMR technique. The NMR technique was also applied to the analysis of the soluble fractions and the decomposition of insoluble parts by heat treatment. It was found that in the melt state, rapid dynamics in the molten state considerab...

The systematic investigations of the synthesis, thermal properties, and microstructures of Isotactic poly(3-methyl-l-butene) (iP3M1B) was performed. Three C2 methallocene catalysts, namely, (DMSBMPI)ZrCI2, (DMSBI)ZrCl2, and (DMSMBI)ZrC12 with MAO, are used for the synthesis of iP3M1B. It was synthesized in a 200 mL three-necked glass bottle equippe...

Additive effects of dialkylaluminum hydrides on propylene-1,3 -butadiene copolymerization were investigated with an isospecific zirconocene catalyst, rac-dimethylsilylbis(2-methyl-4-phenylindenyl)zirconium dichloride (4Ph), activated by modified methylaluminoxane. Dialkylaluminum hydrides improved the apparent selectivity for 1,2-insertion of 1,3-b...

Group 4 [η1:η3-tert-butyl(dimethylfluorenylsilyl)amido]dimethyl complexes [t-BuNSiMe2Flu]MMe2 (M=Ti, 1; Zr, 2; Hf, 3) were synthesized in a one-pot synthesis starting from the ligand, MeLi and MCl4 (M=Ti, Zr, Hf), respectively. The structures of these complexes were determined by X-ray crystallography and the results obtained revealed that the fluo...

Introduction of polar affinity into polypropylene has been extensively studied worldwide. Copolymerization techniques are one of the most powerful tools to control location and amount of polar group in polymers. Copolymerization of propylene with 1,3-butadiene has been studied because double bond in copolymer derived from 1,3-butadiene can be conve...

Solution NMR has been usually used for molecular structure characterization of organic solutes. However, it is not easy to detect their microstructures of insoluble semi-crystalline polymers, such as aromatic polymers, polyolefins with bulky side group, because of their bad solubility. One advantage of 13C solid state NMR is to be used for end-grou...

Crystalline styrene−butadiene−styrene (SBS) triblock copolymers consisting of elastic cis-polybutadiene (cis-PB) chemically bonded with crystallizable syndiotactic polystyrene (syn-PS) were synthesized through a stereospecific sequential triblock copolymerization of S with B catalyzed by C5Me5TiMe3/B(C6F5)3/trioctylaluminum (Al(oct)3) under control...

The isotactic poly(3-methy 1-1-butene) (iP3M1B) was synthesized using homogeneous metallocene catalysts. Microstructure and Molecular Dynamics, such as molecular weight and isotacticity of iP3M1B were studied by DMA and solid-state MAS NMR, though it is insoluble in almost all kinds of available solvents. From solid-state MAS NMR measurements, we c...

The copolymerization of propylene and 3-buten-1-ol protected with alkylaluminum [trimethylaluminum (TMA) or triisobutylaluminum] was conducted with an isospecific zirconocene catalyst [rac-dimethylsilylbis(1-indenyl)zirconium dichloride], combined with methylaluminoxane as a cocatalyst, in the presence of additional TMA or H2 as the chain-transfer...

The copolymerizations of propylene with allyl monomers carrying alcohol or amine were conducted by the rac-dimethylsilylbis(1-indenyl)zirconium dichloride/methylaluminoxane catalyst system. The allyl monomers were pretreated by alkylaluminum before the polymerization. Although the efficiency of the introduction of allyl alcohol-based comonomer was...

Copolymerization of olefins (ethylene and propylene) and 5-hexen-1-ol pretreated with alkylaluminum was performed using [dimethysilylbis(9-fluorenyl)]zirconium dichloride/methylaluminoxane as the catalyst. The copolymerization required extra addition of alkylaluminum to prevent deactivation of the catalyst when 5-hexen-1-ol was pretreated with trim...

Polymerization of ethylene and propylene was conducted with a Tebbe-type Ti(III) complex [Cp 2Ti(μ-Cl) 2AIXY, (X, Y=Et, Cl)] combined with methylaluminoxane (MAO) cocatalyst. The polymerization activity increased with decreasing number of the Et-group in the Tebbe-type complex. The activity was improved also by removal of the AlMe 3 from MAO. This...

Cp2Ti (μ-C1) 2AIXY (X, Y=Cl, Et) で表される3価Tebbe型チタノセン錯体とメチルアルミノキサン (MAO) を組み合わせた触媒系によりエチレンおよびプロピレンの重合を行った. これらの重合においては, Tebbe型錯体中にアルキル基を含まないもの, またAIMe3を除去したメチルアルミノキサン (MAO) を用いた場合に高い活性を示した. また, プロピレン重合においては異種結合を多く含むポリマーが生成した.

The copolymerization of ethylene and 5-hexen-1-ol pretreated with trimethylaluminium was performed using [ethylene(1-indenyl)(9-fluorenyl)]zirconium dichloride/methylaluminoxane as the catalyst. The 5-hexen-1-ol unit in the copolymer could be increased to about 50 mol-% with increasing [5-hexen-1-ol/ethylene[ ratio. 13C NMR analysis proved that the...

Three kinds of MgCl2-supported trivalent titanocene catalyst (Cat. 1: Cp2TiCl2AlCl2/MgCl2, Cat. 2: CpCp*TiCl/MgCl2, Cat. 3: Cp2TiCl/MgCl2) were prepared and tested for propylene polymerization. It was found that Cat. 1, combined with ordinary alkylaluminum as cocatalyst, produced PP containing 31.8 wt % of isotactic PP in fairly good yield. On the...

Propene polymerization was conducted by [η3:η1-tert-butyl(dimethylfluorenylsilyl)amido]dimethyltitanium combined with B(C6F5)3 or methylaluminoxane (MAO) as a cocatalyst in the presence or absence of various trialkylaluminums: Me3Al, Et3Al, iBu3Al (triisobutylaluminum) and Oct3Al (trioctylaluminum). In the case of living polymerization with B(C6F5)...

Propene polymerization was conducted with the [t-BuNSiMe2Flu]TiMe2/B(C6F5)3 catalyst at –50°C at various concentrations of propene. The polymerization proceeds in a living manner regardless of the propene concentration employed. Molecular weight of polymer obtained in a certain polymerization time with low monomer conversion increases with increasi...

Propene polymerization was conducted by [η1:η3-tert-butyl(dimethylfluorenylsilyl)amido]dimethyltitanium combined with B(C6F5)3 as a cocatalyst. Living polymerization proceeded at -50 °C in the presence of suitable amounts of B(C6F5)3 and AlOct3. Addition of AlOct3 and excess B(C6F5)3 drastically increased the polymer yield and molecular weight with...

Propene polymerization was conducted with titanocene (Cp2TiMe2, CpTiMe2; Cp = η5-C5H5, Cp* = η5-C5Me5)/organoborane (B(C6F5)3, Ph3CB(C6F5)4) catalysts at −50°C using toluene as a solvent. The polymer obtained with Cp2TiMe2/Ph3CB(C6F5)4 is less isotactic than that obtained with Cp2TiMe2/B(C6F5)3. However, the isospecificity of the former catalyst is...

Four non-bridged dimethylzirconocene complexes, i.e., bis(η5-cyclopentadienyl)dimethylzirconium (1), (η5-cyclopentadienyl) (η5-fluorenyl)dimethylzirconium (2), bis(η5-indenyl)dimethylzirconium (3) and (η5-cyclopentadienyl)(η5-pentamethylcyclopentadienyl)dimethylzirconium (4) were synthesized and used as a catalyst for the methyl methacrylate polyme...

Polymerization of propene was conducted by [t-BuNSiMe2Flu]TiMe2-based catalysts at −50 °C in the presence of trioctylaluminum. When B(C6F5)3 was used as a cocatalyst, polymer yield monotonically increased with increasing polymerization time. The polypropene obtained showed narrow molecular weight distribution, and the number average molecular weigh...

It is of great importance in propene polymerization to control molecular weight and molecular weight distribution as well as isotacticity. Propene polymerization was carried out with an isospecific MgCl2/TiCl4-Cp2TiMe2 catalyst in the presence of various kinds of external Lewis bases. It was found that the molecular weight distribution of the isota...

Propene polymerization was conducted by a MgCl2/diisobutyl phthalate/TiCl4 catalyst combined with AlEt3 as cocatalyst. The polymerization was quenched by oxygen gas, and the polymer was fractionated into atactic and isotactic parts with boiling heptane. Each part was analyzed by 1H NMR. The spectra showed the resonances of vinylidene, vinyl, and hy...

Propene polymerization was conducted with TiCl4/(Lewis base)/MgCl2-Cp2TiMe2 catalysts in the presence of ethyl benzoate (EB) and/or 2,2-diisobutyl-1,3-dimethoxypropane (DBDMP). The addition of small amounts of these Lewis bases to MgCl2 before supporting TiCl4 decreased the amount of Ti in the catalyst and improved catalyst isospecificity. The resu...

MOLECULES composed of interlocking rings are termed catenanes. Since the first synthesis of a two-ring catenane (a [2]catenane) in 19601, these and related interlinked compounds have attracted considerable interest2-10, in part from the perspective of forming molecular devices and nanoscale architectures11,12. Here we report the formation of a [2]c...