Acta Polymerica最新文献_第2页

Effective conjugation length and UV/vis spectra of oligomers 低聚物的有效共轭长度和紫外/可见光谱

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480905

H. Meier, U. Stalmach, H. Kolshorn

引用次数: 344

Morphology of banded spherulites in poly(ε-caprolactone)/poly(styrene-ran-acrylonitrile) blends 聚(ε-己内酯)/聚(苯乙烯-丙烯腈)共混物中带状球粒的形态

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480902

Chun Wang, R. Thomann, J. Kressler, Y. Thomann, K. Crämer, B. Stühn, P. Svoboda, T. Inoue

{"title":"Morphology of banded spherulites in poly(ε-caprolactone)/poly(styrene-ran-acrylonitrile) blends","authors":"Chun Wang, R. Thomann, J. Kressler, Y. Thomann, K. Crämer, B. Stühn, P. Svoboda, T. Inoue","doi":"10.1002/actp.1997.010480902","DOIUrl":"10.1002/actp.1997.010480902","url":null,"abstract":"The occurrence of banded spherulites in blends of poly(ε-caprolactone) with poly(styrene-ran-acrylonitrile) is studied by means of optical-, scanning electron-, environmental scanning electron-, and atomic force-microscopy as well as smallangle X-ray scattering. The measurements reveal that lamellae are confined in fibrils that bend periodically from the center of spherulites in a radial direction. The fibrils show also a regular spacing in the lateral direction. Single bent lamellae can be observed by atomic force microscopy after permanganic etching. The enrichment of amorphous material near to the growth front of the spherulites can be directly observed by polarized light microscopy after temperature jump experiments. The excluded amorphous material on the surface of the growing spherulites has the shape of droplets. This might be the main reason for the initiation of the bending process because the result is a non-uniform stress distribution acting on the growing lamellae at the interface between spherulites and the surrounding melt. The amorphous material of the blends can be found in three areas as observed by small-angle X-ray scattering experiments and microscopical methods: (i) between the lamellae, (ii) excluded from the interlamellar region but within the spherulite, and (iii) for high contents of non-crystallizable material, it can be excluded from the spherulite. The banding periodicity of spherulites as a function of the crystallization temperature can be described in terms of two models, based either (i) on the inherent twisting of lamellae perpendicular to the axis of a screw dislocation or (ii) on the dependence of the diffusion of amorphous material away from the growth front of lamellae and the temperature dependence of the rate of crystallization. Both models fail at very low supercoolings near to temperatures where the banding disappears completely.","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"48 9","pages":"354-362"},"PeriodicalIF":0.0,"publicationDate":"2003-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/actp.1997.010480902","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82288017","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: 9

Defects and textures in nematic MCLCPs† 向列MCLCPs中的缺陷和织构

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480901

C. Noël

引用次数: 2

Combining oxidative addition and polymerization: A study towards the synthesis of macromonomers 氧化加成与聚合相结合:合成大单体的研究

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010481003

W. Massa, N. Faza, Hak-Chul Kang, C. Focke, W. Heitz

引用次数: 18

Aromatic polymers obtained by precipitation polycondensation. 6. Morphology of polyketone particles 沉淀法缩聚制得芳香族聚合物。6. 聚酮颗粒的形态

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480706

M. G. Zolotukhin, F. J. Balta Calleja, D. R. Rueda, J. M. Palacios

引用次数: 7

Behavior and properties of side chain thermotropic liquid crystal polymers 侧链热致液晶聚合物的行为与性能

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480301

J. C. Dubois, P. Le Barny, M. Mauzac, C. Noel

引用次数: 18

Regioselective polycondensation of benzyl 2-amino-2-deoxy-α-D-glucopyranoside hydrochloride with carbon dioxide 2-氨基-2-脱氧-α- d -氨基葡萄糖苷盐酸盐与二氧化碳的区域选择性缩聚

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480803

J. Kadokawa, T. Horiguchi, E. Sunaga, M. Karasu, H. Tagaya, K. Chiba

引用次数: 7

Polypropylene growth on silica-supported metallocene catalysts: A microscopic study to explain kinetic behavior especially in early polymerization stages 聚丙烯在二氧化硅负载的茂金属催化剂上生长:一个微观研究来解释动力学行为，特别是在聚合的早期阶段

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480907

B. Steinmetz, B. Tesche, C. Przybyla, J. Zechlin, G. Fink

引用次数: 27

Two-dimensional computer simulation of spherulite formation by branching lamellae 分支薄片形成球晶的二维计算机模拟

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480704

G. Kalinka, G. Hinrichsen

引用次数: 6

X-Ray investigation of the structure of polyurethane elastomers based on 1,5-naphthalene diisocyanate 1,5-萘二异氰酸酯聚氨酯弹性体结构的x射线研究

Acta Polymerica Pub Date : 2003-03-11 DOI: 10.1002/actp.1997.010480903

R. Androsch, J. Blackwell, S. N. Chvalun, G. Festel, C. D. Eisenbach

{"title":"X-Ray investigation of the structure of polyurethane elastomers based on 1,5-naphthalene diisocyanate","authors":"R. Androsch, J. Blackwell, S. N. Chvalun, G. Festel, C. D. Eisenbach","doi":"10.1002/actp.1997.010480903","DOIUrl":"10.1002/actp.1997.010480903","url":null,"abstract":"The structure of the crystalline hard domains of polyurethane elastomers based on 1,5-naphthalene diisocyanate (NDI) has been investigated by X-ray methods. The specimens were pressed films prepared from NDI and 1,4-butanediol (chain extender), with poly(oxytetramethylene) as the soft segments. Small angle X-ray data show that the hard domains are lamellae oriented preferentially with their planes parallel to the film surface. The corresponding wide angle data show that the hard domains are crystalline, and that the degree of crystallinity can be more than 60%. The hard segment chains are relatively extended and are oriented perpendicular to the film surface: they probably form a staggered array in which they are linked in sheets by hydrogen bonds. Molecular models suggest that the hydrogen bonds are shorter, and hence stronger, than those formed in the hard domains of equivalent elastomers based on diphenylmethane diisocyanate (MDI) or dicyclohexylmethane diisocyanate (HMDI). In addition, the stacking of the naphthylene units is unencumbered by the presence of the bridge methylene groups in the latter systems, and these structural features probably account for the higher melting temperature of the hard domains.","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"48 9","pages":"363-368"},"PeriodicalIF":0.0,"publicationDate":"2003-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/actp.1997.010480903","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91405741","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