Journal of Polymer Science. Part B, Polymer Physics最新文献_第3页

Blends of fatty-acid-modified dendrimers with polyolefins This article is a US Government work and, as such, is in the public domain in the United States of America. 这篇文章是美国政府的一项工作，因此在美利坚合众国属于公有领域。

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Journal of Polymer Science. Part B, Polymer Physics Pub Date : 2000-01-01 DOI: 10.1002/(SICI)1099-0488(20000101)38:1<95::AID-POLB12>3.3.CO;2-X

B. Bauer, A. Ramzi, Da-Wei Liu, R. Scherrenberg, P. Froehling, J. Joosten

引用次数: 0

Strain effects on physical gelation of crystallizing isotactic polypropylene 应变对等规聚丙烯结晶物理胶凝的影响

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Journal of Polymer Science. Part B, Polymer Physics Pub Date : 1999-12-15 DOI: 10.1002/(SICI)1099-0488(19991215)37:24<3512::AID-POLB12>3.0.CO;2-#

N. Pogodina, H. Winter, S. Srinivas

{"title":"Strain effects on physical gelation of crystallizing isotactic polypropylene","authors":"N. Pogodina, H. Winter, S. Srinivas","doi":"10.1002/(SICI)1099-0488(19991215)37:24<3512::AID-POLB12>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0488(19991215)37:24<3512::AID-POLB12>3.0.CO;2-#","url":null,"abstract":"Early stages of crystallization of polymers may be viewed as thermoreversible physical gelation in which molecular connectivity is introduced by crystallization. Effects of shear strain on the early stages of crystallization of a commercial isotactic polypropylene are studied by dynamic mechanical experiments. Shear creep with large strains (up to γ = 300) on the undercooled melt for short times (the time did not exceed 100 s) was followed by small amplitude oscillatory shear (SAOS) at a strain amplitude (γ a = 0.01) for gel-point detection. The imposed shear strongly accelerates gelation; gel times decrease in a power law with increasing strain. Strain applied during the crystal growth stage enhances gelation much stronger than strain applied in the earlier nucleation stage. For rapid gelation, frequency sweeps are not possible and new methods for gel-point detection need to be explored; here, we propose to estimate the gel point from the storage modulus growth at a single frequency. A value of 10% of the total growth of G' was found to be a good estimate for the gel point. High strain experiments show the complexity of underlying mechanisms of strain-enhanced crystallization and reveal at least two sequential stages in the structure development under shear: at the first stage, crystalline regions connect molecules into a loose network; at the second, stage-intense crystallinity growth within the network proceeds. Results have industrial importance in predicting/tuning structure development and connectivity growth during nonisothermal processing. Morphological study of the early stages of crystallization under strain is underway to explore molecular mechanisms, which govern the gelation process.","PeriodicalId":16853,"journal":{"name":"Journal of Polymer Science. Part B, Polymer Physics","volume":"24 1","pages":"3512-3519"},"PeriodicalIF":0.0,"publicationDate":"1999-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75576206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 73

Physical gelation of melamine formaldehyde resin solutions. II. A combined light‐scattering and low‐resolution relaxation proton NMR study 三聚氰胺甲醛树脂物理胶凝溶液。2结合光散射和低分辨率弛豫质子核磁共振研究

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Journal of Polymer Science. Part B, Polymer Physics Pub Date : 1999-12-01 DOI: 10.1002/(SICI)1099-0488(19991201)37:23<3307::AID-POLB6>3.0.CO;2-#

S. Jahromi, V. Litvinov, E. Geladé

{"title":"Physical gelation of melamine formaldehyde resin solutions. II. A combined light‐scattering and low‐resolution relaxation proton NMR study","authors":"S. Jahromi, V. Litvinov, E. Geladé","doi":"10.1002/(SICI)1099-0488(19991201)37:23<3307::AID-POLB6>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0488(19991201)37:23<3307::AID-POLB6>3.0.CO;2-#","url":null,"abstract":"The kinetics of physical gelation in aqueous melamine formaldehyde (MF) resin solutions were studied with the aid of low-resolution 1H NMR T2 relaxation experiments in combination with both static and dynamic light-scattering measurements. The investigations were conducted on a series of MF resins with increasing degrees of condensation. We show that MF aggregates (aided by hydrogen bonds) were immediately formed upon cooling from reaction to room temperature, that is, storage temperature. Surprisingly, the growth of these aggregates, which eventually led to the formation of a physical gel, did not have a major effect on molecular mobility. By means of light-scattering experiments, we were able to monitor the increase of the size of MF aggregates as a function of storage time. The physically gelled MF solutions were subjected to heating and subsequent cooling runs and again studied by light-scattering and nuclear magnetic resonance (NMR) experiments. MF aggregates were destroyed, depending on the degree of condensation, in the temperature range 35–60 °C according to NMR, and 40–75 °C as determined by light scattering. The process of physical gelation was reversible; upon subsequent cooling, the MF aggregates were formed anew. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 3307–3318, 1999","PeriodicalId":16853,"journal":{"name":"Journal of Polymer Science. Part B, Polymer Physics","volume":"1 1","pages":"3307-3318"},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89372008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20

Phase structures and transition behaviors in polymers containing rigid rodlike backbones with flexible side chains. V. Methylene side-chain effects on structure and molecular motion in a series of polyimides 具有柔性侧链的刚性棒状骨架聚合物的相结构和转变行为。亚甲基侧链效应对一系列聚酰亚胺结构和分子运动的影响

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Journal of Polymer Science. Part B, Polymer Physics Pub Date : 1999-07-15 DOI: 10.1002/(SICI)1099-0488(19990715)37:14<1633::AID-POLB8>3.0.CO;2-#

K. Mccreight, J. J. Ge, M. Guo, I. Mann, Fuming Li, Zhihao Shen, Xiaoming Jin, F. Harris, Stephen Z. D. Cheng

{"title":"Phase structures and transition behaviors in polymers containing rigid rodlike backbones with flexible side chains. V. Methylene side-chain effects on structure and molecular motion in a series of polyimides","authors":"K. Mccreight, J. J. Ge, M. Guo, I. Mann, Fuming Li, Zhihao Shen, Xiaoming Jin, F. Harris, Stephen Z. D. Cheng","doi":"10.1002/(SICI)1099-0488(19990715)37:14<1633::AID-POLB8>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0488(19990715)37:14<1633::AID-POLB8>3.0.CO;2-#","url":null,"abstract":"A series of organo-soluble hairy-rod polyimides was recently synthesized from 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) and di[n-alkyl]-4,4′-diamino-6,6′-dibromo-2,2′-biphenyldicarboxylate with side chains of varying lengths (the numbers of methylene units), BACBP(n). Dynamic mechanical (DM) results reveal two cooperative relaxation processes for BACBPs(n > 10), which correspond to the two (low- and high-) transition temperatures observed in differential scanning calorimetry (DSC). For BACBPs(n 10)] and possibly the medium- [for BACBPs(n 10)] adopt monoclinic unit cells, whereas those having the short side chains [BACBPs(n ≤ 10)] possess hexagonal unit cells. The drastic temperature difference between the low- and medium-relaxation processes observed in DM experiments may be explained because of a change in the lateral packing arising from the variation of the side-chain length. The limited mobility afforded the BACBPs(n ≤ 10) is a result of their more ordered conformation and interdigitation between the neighboring side chains. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1633–1646, 1999","PeriodicalId":16853,"journal":{"name":"Journal of Polymer Science. Part B, Polymer Physics","volume":"37 1","pages":"1633-1646"},"PeriodicalIF":0.0,"publicationDate":"1999-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81789372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 30

Differential size‐exclusion chromatography for the analysis of gelatin–polyelectrolyte complexes 明胶-聚电解质复合物的差异尺寸-排除色谱分析

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Journal of Polymer Science. Part B, Polymer Physics Pub Date : 1999-02-15 DOI: 10.1002/(SICI)1099-0488(19990215)37:4<275::AID-POLB2>3.0.CO;2-#

C. A. Harrison, J. S. Tan

{"title":"Differential size‐exclusion chromatography for the analysis of gelatin–polyelectrolyte complexes","authors":"C. A. Harrison, J. S. Tan","doi":"10.1002/(SICI)1099-0488(19990215)37:4<275::AID-POLB2>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0488(19990215)37:4<275::AID-POLB2>3.0.CO;2-#","url":null,"abstract":"Differential size-exclusion chromatography (SEC) is used to characterize complexes formed between gelatin and two synthetic polyelectrolytes, sodium poly(styrenesulfonate) and sodium poly(2-acrylamido-2-methylpropanesulfonate). The analysis is performed under aqueous, low-salt conditions where maximum complexation between gelatin and the polyelectrolytes occurs. The adsorption effects that are commonly encountered in conventional SEC for gelatin and other charged polymers chromatographed under these solution conditions are minimized, because the columns are constantly equilibrated with the analytes in the mobile phase. Analyte solutions of identical composition, but of higher or lower concentration than that contained in the mobile phase, are injected, resulting in positive or negative detector responses, respectively. This method can separate the complexes from individual components, and can be used to determine relative sizes and stoichiometries of the complexes as a function of both the input ratio of gelatin to polyelectrolyte and the molecular weight of the polyelectrolyte.","PeriodicalId":16853,"journal":{"name":"Journal of Polymer Science. Part B, Polymer Physics","volume":"5 1","pages":"275-280"},"PeriodicalIF":0.0,"publicationDate":"1999-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90856316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Morphology of homogeneous copolymers of ethylene and 1-octene. II. Structural changes on annealing 乙烯-辛烯均相共聚物的形貌。2退火后的结构变化

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Journal of Polymer Science. Part B, Polymer Physics Pub Date : 1999-01-01 DOI: 10.1002/(SICI)1099-0488(19990101)37:1<83::AID-POLB8>3.0.CO;2-#

M. Peeters, B. Goderis, H. Reynaers, V. Mathot

{"title":"Morphology of homogeneous copolymers of ethylene and 1-octene. II. Structural changes on annealing","authors":"M. Peeters, B. Goderis, H. Reynaers, V. Mathot","doi":"10.1002/(SICI)1099-0488(19990101)37:1<83::AID-POLB8>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0488(19990101)37:1<83::AID-POLB8>3.0.CO;2-#","url":null,"abstract":"Based on DSC evidence, annealing of ethylene-1-octene copolymers results in a gradually increasing thermal stability of the original, metastable, crystals. SAXS and WAXD were used to monitor the structural changes involved after isothermal annealing for a fixed time at step-wise higher temperatures. A series of samples that differ in molar mass and comonomer content, ranging from 0 to 11.8 mol % 1-octene, were cooled at two extreme rates from 150°C, i.e., a quenching into liquid nitrogen and a controlled cooling at 0.1°C per minute to room temperature. The crystallinities of the quenched linear polyethylenes (LPEs), being included in this study as reference materials, and of the quenched copolymer with a 1-octene content of 2.1 mol % are always found to be lower than the crystallinities of the slowly cooled samples. On the other hand, higher crystallinities can be found for the quenched copolymers with a higher comonomer content compared to the slowly cooled specimens. A sequence of cocrystallization and recrystallization events is proposed to explain this contraintuitive, but reproducible experimental fact. This reasoning can also account for the steeper increase of the amorphous layer thickness of the latter slowly cooled copolymers compared to the quenched samples. All copolymers show a very moderate increase of the lamellar thickness after each heating step. Besides additional crystallization and recrystallization, lateral growth of the crystals and an increase of the crystallite density can account for the gradual increase of the thermal stability of copolymer crystals during prolonged annealing. The morphological effects observed for the LPEs confirm earlier findings. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 83–100, 1999","PeriodicalId":16853,"journal":{"name":"Journal of Polymer Science. Part B, Polymer Physics","volume":"20 1","pages":"83-100"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73649362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 35

Macroscopic polymer analogues 宏观高分子类似物

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Journal of Polymer Science. Part B, Polymer Physics Pub Date : 1998-12-01 DOI: 10.1002/(SICI)1099-0488(199812)36:17<3147::AID-POLB14>3.0.CO;2-#

G. Beaucage, S. K. Sukumaran, S. Rane, D. Kohls

引用次数: 1

Partially fluorinated thermally responsive latices of linear and crosslinked copolymers 线性和交联共聚物的部分氟化热响应晶格

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Journal of Polymer Science. Part B, Polymer Physics Pub Date : 1998-09-15 DOI: 10.1002/(SICI)1099-0488(19980915)36:12<2141::AID-POLB12>3.0.CO;2-#

T. Lowe, Myriam Benhaddou, H. Tenhu

{"title":"Partially fluorinated thermally responsive latices of linear and crosslinked copolymers","authors":"T. Lowe, Myriam Benhaddou, H. Tenhu","doi":"10.1002/(SICI)1099-0488(19980915)36:12<2141::AID-POLB12>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0488(19980915)36:12<2141::AID-POLB12>3.0.CO;2-#","url":null,"abstract":"A series of thermally responsive copolymers of N-isopropylacrylamide (NIPAAM) with a fluorinated hydrophobic comonomer, either hexafluoroisopropylmethacrylate (HFIPMA) or 2,2,3,3,4,4-hexafluorobutylmethacrylate (HFBMA) and a hydrophilic comonomer, methacrylic acid (MAA), were synthesized by emulsion polymerization. The chemical structures of the copolymers were studied by the IR technique. Dynamic light scattering (DLS) showed that aqueous latices of the copolymers exhibited swelling–deswelling changes typical to PNIPAAM; the degree of swelling as well as the temperature at which the polymers collapse depended on the chemical structure of the comonomers. Endotherms related to the contraction of the polymers were studied by differential scanning calorimetry (DSC). A combination of DLS and DSC results revealed that the hydrophobic and hydrophilic units in the copolymers strongly affected the swelling behavior, as well as the local environment of the PNIPAAM chains. The comonomer HFIPMA increased the hydrophobicity of NIPAAM, reduced the swelling, and caused coagulation of the copolymer of NIPAAM and HFIPMA at temperatures above the critical temperature. Hydrophobicity of HFIPMA also affected the rheological properties of the latex. The HFBMA comonomer increased the swelling of the latex particles. Methacrylic acid added into the associating copolymers made the copolymers to show polyelectrolyte behavior with an increase of swelling and a decrease of the enthalpy change upon the collapse. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. B Polym. Phys. 36: 2141–2152, 1998","PeriodicalId":16853,"journal":{"name":"Journal of Polymer Science. Part B, Polymer Physics","volume":"21 1","pages":"2141-2152"},"PeriodicalIF":0.0,"publicationDate":"1998-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73755806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 18

Theoretical study of sorption‐induced bending of polypyrrole films 聚吡咯薄膜吸附诱导弯曲的理论研究

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Journal of Polymer Science. Part B, Polymer Physics Pub Date : 1998-09-15 DOI: 10.1002/(SICI)1099-0488(19980915)36:12<2237::AID-POLB20>3.0.CO;2-#

H. Okuzaki, T. Kuwabara, T. Kunugi

引用次数: 19

Film‐forming ability and mechanical properties of coalesced latex blends 聚结乳胶共混物的成膜能力和机械性能

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Journal of Polymer Science. Part B, Polymer Physics Pub Date : 1997-09-30 DOI: 10.1002/(SICI)1099-0488(19970930)35:13<2093::AID-POLB10>3.0.CO;2-#

S. Lepizzera, C. Lhommeau, G. Dilger, T. Pith, M. Lambla

{"title":"Film‐forming ability and mechanical properties of coalesced latex blends","authors":"S. Lepizzera, C. Lhommeau, G. Dilger, T. Pith, M. Lambla","doi":"10.1002/(SICI)1099-0488(19970930)35:13<2093::AID-POLB10>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0488(19970930)35:13<2093::AID-POLB10>3.0.CO;2-#","url":null,"abstract":"The film-forming ability of latex blends (hard latex + soft latex) and the mechanical behavior at finite strain of latex blend films (soft matrix with tough inclusions) has been investigated. The maximum weight fraction of hard latex particles (ϕmax) which still gives rise to transparent and crack-free films has been used as film-forming ability criterion. It was shown that when the Tg of the soft latex is low (Tg(soft) < 0°C), ϕmax is constant and equal to 0.55 because the film-forming ability is controlled by contacts between hard particles. Nevertheless, the expected effect of Tg(soft) on film-forming ability is observed (i.e., ϕmax decreases when Tg(soft) increases) when Tg(soft) is above 0°C. From the mechanical behavior point of view, it was shown that the two main parameters controlling the mechanical behavior of latex blend films are: the mechanical properties of the soft polymer because it represents the continuous matrix and the weight fraction of hard latex particles since they enhance the local deformation of matrix under load. However, it was also proven that debounding between the Tg latex particles and low Tg matrix occurs rapidly (at an elongation ratio ≈ 30%) during uniaxial strain experiments and has to be taken into account in order to gain a thorough understanding of the mechanical behavior of these biphasic films. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2093–2101, 1997","PeriodicalId":16853,"journal":{"name":"Journal of Polymer Science. Part B, Polymer Physics","volume":"81 1","pages":"2093-2101"},"PeriodicalIF":0.0,"publicationDate":"1997-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74174463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 43