Acta Polymerica最新文献_第5页

Syntheses and spectroscopic pH titrations of naphthol-labeled poly(methacrylic acid)s 萘酚标记聚甲基丙烯酸的合成及光谱pH滴定

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480405

Y. Itoh, K. Ogura, T. Hirota, A. Hachimori, K. Abe

引用次数: 3

Polythienylenevinylene as promoter of hole injection from ITO into bilayer light emitting diodes 聚乙烯烯作为ITO空穴注入双层发光二极管的促进剂

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010481006

Y.-H. Tak, S. Mang, A. Greiner, H. Bässler, S. Pfeiffer, H.-H. Hörhold

引用次数: 7

Real-space composition–depth profiling in polymeric samples to 3 nm resolution using the 2H(3He, 1H)4He nuclear reaction 利用2H(3He, 1H)4He核反应对聚合物样品进行3nm分辨率的实时空间成分深度分析

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010481204

T. Kerle, F. Scheffold, A. Losch, U. Steiner, G. Schatz, J. Klein

{"title":"Real-space composition–depth profiling in polymeric samples to 3 nm resolution using the 2H(3He, 1H)4He nuclear reaction","authors":"T. Kerle, F. Scheffold, A. Losch, U. Steiner, G. Schatz, J. Klein","doi":"10.1002/actp.1997.010481204","DOIUrl":"10.1002/actp.1997.010481204","url":null,"abstract":"Direct depth profiling techniques to date have largely lacked the necessary depth resolution to investigate interfacial phenomena of the order of the bulk correlation length (5—10 nm for a wide range of systems). Here we investigate the optimal spatial resolution and depth of probe that may be attained for composition — depth profiling of polymeric samples via nuclear reaction analysis (NRA) using the 2H(3He, 1H)4He reaction. We find that the spatial resolution can be greatly improved by using a grazing incidence geometry of the incident 3He beam on the sample, and analyzing the emitted protons in a backwards direction. This results in spatial resolutions down to about 3 nm at the sample surface, compared to a value of some 7 nm or more previously reported in earlier studies when emitted α-particles were detected in the forward direction. At the same time the depth to which samples can be profiled via the backwards emitted protons may be considerably extended relative to the α-particle detection mode, when the 3He beam impinges on the sample surface at normal incidence (up to about 4 μm into the sample for incident energies of 1.2 MeV in the proton-detection mode compared to only 1 μm for the equivalent α-particle detection mode).","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"48 12","pages":"548-552"},"PeriodicalIF":0.0,"publicationDate":"2003-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/actp.1997.010481204","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85806168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Craze formation in amorphous polymers in relation to the flow and main transition 非晶聚合物中裂纹形成与流动和主转变的关系

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480303

J.-U. Starke, G. Schulze, G. H. Michler

{"title":"Craze formation in amorphous polymers in relation to the flow and main transition","authors":"J.-U. Starke, G. Schulze, G. H. Michler","doi":"10.1002/actp.1997.010480303","DOIUrl":"https://doi.org/10.1002/actp.1997.010480303","url":null,"abstract":"Crazes were produced and analyzed in unnotched tensile bars of poly(styrene-co-acrylonitrile) (SAN) and polycarbonate (PC) in creep experiments above TVF (the Vogel temperature). The craze microstructure was investigated as a function of temperature (T) and load (σ) by means of small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Contrary to expectation, the scattering vector of maximum intensity (smax), which is inversely proportional to the distance between the fibrils of crazes, was not linearly dependent on σ at constant temperature. At the highest stresses (regime III), smax was independent of stress, and the average distance between the fibrils reaches a minimum value. At intermediate stresses (regime II), a strong increase of fibrillation energy Γ was detected, as the temperature was reduced. In the vicinity of TVF, Γ reached values of the order of the polymer chain fracture energy. At the lowest stresses (regime I), the energy of fibril formation was independent of temperature and corresponded to the van der Waals surface energy. The molecular motions during fibril formation may be linked to local stress-induced flow processes of polymer chains (regime I) and α-relaxations (regime II). Increasing stress restricts the range of mobility of macromolecules to shorter and shorter units and a transition from the formation of fibrillated crazes to homogeneous crazes or shear deformation processes occurs at the highest stresses (regime III). A pressure—temperature diagram was constructed from the transition between the regimes, particularly at negative pressure.","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"48 3","pages":"92-99"},"PeriodicalIF":0.0,"publicationDate":"2003-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/actp.1997.010480303","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91866073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12

Rubber toughening of polystyrene–acrylonitrile copolymers 聚苯乙烯-丙烯腈共聚物的橡胶增韧

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010481205

F. Ramsteiner, G. E. McKee, W. Heckmann, W. Fischer, M. Fischer

引用次数: 7

Measuring chain diffusion coefficients and activation energy during coalescence of fluorescence-labeled hard latex particles 测定荧光标记硬胶乳颗粒聚并过程中的链扩散系数和活化能

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480806

M. Canpolat, Ö. Pekcan

{"title":"Measuring chain diffusion coefficients and activation energy during coalescence of fluorescence-labeled hard latex particles","authors":"M. Canpolat, Ö. Pekcan","doi":"10.1002/actp.1997.010480806","DOIUrl":"10.1002/actp.1997.010480806","url":null,"abstract":"The steady-state fluorescence (SSF) technique was used to study interdiffusion of polymer chains across the particle–particle junction during film formation from hard latex particles. The latex films were prepared from pyrene (P) and naphthalene (N) labeled poly(methyl methacrylate) (PMMA) particles and annealed for long time intervals above the glass transition temperature (Tg) between 170 and 220°C. A novel correction method was suggested and employed to eliminate changing of the optical density of latex films after such annealing processes. P and N fluorescence intensities solely from the energy-transfer processes were monitored versus annealing time and were used to measure the polymer chain diffusion coefficients Dp and DN, which were found to be between 4.34 × 10–14 and 7.68 × 10–13 cm2/s for an annealing temperature between 170 and 220°C. Using these diffusion coefficients with the Arrhenius relation, the diffusion activation energy for the polymer backbone was found to be 28 kcal/mol.","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"48 8","pages":"326-333"},"PeriodicalIF":0.0,"publicationDate":"2003-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/actp.1997.010480806","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85252859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Poly(di-n-pentylsilylene) copolymers containing diethyleneglycol-diethylether side chains 含有二乙二醇-二乙醚侧链的聚(二正戊基硅烯)共聚物

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480805

L. A. Schwegler, M. Möller

引用次数: 5

Order and molecular motion in wholly aromatic copolyesters 全芳香族共聚酯的序和分子运动

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010481202

F. v. Stein, A. Martin, W. Gronski, J. Blackwell, S. N. Chvalun, H. R. Kricheldorf

{"title":"Order and molecular motion in wholly aromatic copolyesters","authors":"F. v. Stein, A. Martin, W. Gronski, J. Blackwell, S. N. Chvalun, H. R. Kricheldorf","doi":"10.1002/actp.1997.010481202","DOIUrl":"10.1002/actp.1997.010481202","url":null,"abstract":"The order and molecular dynamics of wholly aromatic thermotropic copolyesters prepared from hydroxybenzoic acid (HBA), hydroquinone (HQ) and phenoxyterephthalic acid (Ph-O-TPA) have been studied by X-ray analysis and deuteron NMR spectroscopy of specimens containing either deuterated hydroquinone or deuterated phenoxy side-chain units. X-ray analysis shows the coexistence of nematic and three-dimensionally ordered regions that are characterized by registry of adjacent chains with interleaved side groups. The molecular motions in these nematic/three-dimensionally ordered polymers are compared to those of a highly crystalline copolyester prepared from deuterated TPA and HQ. In the fast motional limit the motion in the crystalline system is characterized by 180° flips about the TPA axis, whereas in the nematic/three-dimensionally ordered copolyester the same type of axially symmetric spectrum is observed for both the nematic and the three-dimensionally ordered regions. The motion of the HQ units is characterized by rotational diffusion about the C1C4 axis, augmented by fast rotational fluctuation of this axis about the main-chain direction. A model of free rotation about the axis of the phenyl group augmented by librations of restricted amplitude about the PhO-TPA bond for the ordered regions superimposed by slow axial motions about the main-chain axis in the nematic phase is consistent with both the NMR data and X-ray analysis.","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"48 12","pages":"527-535"},"PeriodicalIF":0.0,"publicationDate":"2003-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/actp.1997.010481202","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91322170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Phase inversion with gel/sol/gel-treatment — a new technology for the formation of hollow-fiber membranes at a wet spinning process 凝胶/溶胶/凝胶处理相转化——湿法纺丝工艺中形成中空纤维膜的新技术

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480304

W. Albrecht, Th. Weigel, D. Paul

引用次数: 6

Molecular motions in crystalline and mesomorphic forms of poly(diethylsiloxane) 聚二乙基硅氧烷晶体和亚晶形态的分子运动

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010481102

V. M. Litvinov, V. Macho, H. W. Spiess

引用次数: 12