Pub Date : 1997-09-30DOI: 10.1002/(SICI)1099-0488(19970930)35:13<2193::AID-POLB19>3.0.CO;2-#
G. Gentile, P. Laurienzo, F. Riva, M. G. Volpe
{"title":"Linear poly(etheraroylhydrazides): A correlation between number of methylene sequences and reticular structure","authors":"G. Gentile, P. Laurienzo, F. Riva, M. G. Volpe","doi":"10.1002/(SICI)1099-0488(19970930)35:13<2193::AID-POLB19>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0488(19970930)35:13<2193::AID-POLB19>3.0.CO;2-#","url":null,"abstract":"","PeriodicalId":16853,"journal":{"name":"Journal of Polymer Science. Part B, Polymer Physics","volume":"74 1","pages":"2193-2194"},"PeriodicalIF":0.0,"publicationDate":"1997-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85648273","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}
Pub Date : 1997-09-15DOI: 10.1002/(SICI)1099-0488(19970915)35:12<1963::AID-POLB11>3.0.CO;2-#
A. A. Goodwin, F. Mercer
The relaxation behavior of six fluorinated aromatic poly( ethers ) was investigated using dynamic mechanical analysis. The glass transition temperature was found to increase as the size and rigidity of linking groups increased and varied between 168°C for a dimethyl linking group and 300°C for a bicyclic benzoate ether-linking group. For the α-relaxation the steepness of time/temperature plots and broadness of the loss curves could be qualitatively correlated with chemical structure in a manner predicted by the coupling model of relaxation. Well-separated sub-T g transitions were also observed, as a shoulder on the low temperature side of the α-peak, and as a broad, low loss transition around -100°C. The higher temperature process was similar to the structural relaxation often found in quenched glassy polymers, while the position, intensity, and breadth of the subambient process was sensitive to chemical structure.
{"title":"Dynamic mechanical behavior of fluorinated aromatic poly(ethers)","authors":"A. A. Goodwin, F. Mercer","doi":"10.1002/(SICI)1099-0488(19970915)35:12<1963::AID-POLB11>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0488(19970915)35:12<1963::AID-POLB11>3.0.CO;2-#","url":null,"abstract":"The relaxation behavior of six fluorinated aromatic poly( ethers ) was investigated using dynamic mechanical analysis. The glass transition temperature was found to increase as the size and rigidity of linking groups increased and varied between 168°C for a dimethyl linking group and 300°C for a bicyclic benzoate ether-linking group. For the α-relaxation the steepness of time/temperature plots and broadness of the loss curves could be qualitatively correlated with chemical structure in a manner predicted by the coupling model of relaxation. Well-separated sub-T g transitions were also observed, as a shoulder on the low temperature side of the α-peak, and as a broad, low loss transition around -100°C. The higher temperature process was similar to the structural relaxation often found in quenched glassy polymers, while the position, intensity, and breadth of the subambient process was sensitive to chemical structure.","PeriodicalId":16853,"journal":{"name":"Journal of Polymer Science. Part B, Polymer Physics","volume":"94 1","pages":"1963-1971"},"PeriodicalIF":0.0,"publicationDate":"1997-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85704588","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}
Pub Date : 1996-10-01DOI: 10.1002/(SICI)1099-0488(199610)34:14<2291::AID-POLB1>3.0.CO;2-#
Y. Hwang, G. Patterson, J. R. Stevens
Slowly relaxing longitudinal density fluctuations in an optically perfect sample of bulk poly(n-hexyl methacrylate) (PHMA) have been studied by photon correlation spectroscopy in the temperature range 10-36°C. The glass transition temperature for this sample was in the temperature range 10-36°C. The glass transition temperature for this sample was measured to be T g = -3°C by differential scanning calorimetry. The optical purity of the sample was verified by Rayleigh Brillouin spectroscopy and the Landau Placzek ratio was observed to be 2.3 at 25°C. Light-scattering relaxation functions were obtained over the time range 10 6 -l s. The shape of the relaxation functions broadened as the temperature was lowered towards the glass transition. Quantitative analysis of the results was carried out using the Kohlrausch-Williams-Watts (KWW) function to obtain average relaxation times , and width parameters, β. The width parameter decreased from 0.43 to 0.21 over the temperature interval, as suggested by visual inspection. Average relaxation times shifted with temperature in a manner consistent with previous mechanical studies of the primary glass-rubber relaxation in PHMA. The relaxation functions were also analyzed in terms of a distribution of relaxation rates, G(T). The calculated distributions were unimodal at all temperatures. The average relaxation times obtained from G(T) were in agreement with the KWW analysis, and the shape of the distribution broadened as the sample was cooled. The rate at which G(T) displayed a maximum correlated well with the corresponding frequency of maximum dielectric loss for PHMA. The temperature dependence of these two quantities could be reproduced with an Arrhenius activation energy of 21 Kcal/mol. A consistent picture of the molecular dynamics of PHMA near the glass transition requires a strong secondary relaxation process with a different temperature dependence from the primary glass-rubber relaxation. The present results suggest that the behavior of PHMA is similar to the other poly(alkyl methacrylates).
在10 ~ 36℃的温度范围内，用光子相关光谱研究了光学完美体聚甲基丙烯酸正己酯(PHMA)样品的缓慢弛豫纵向密度波动。该样品的玻璃化转变温度范围为10-36℃。用差示扫描量热法测得该样品的玻璃化转变温度为tg = -3℃。通过瑞利布里渊光谱法验证了样品的光学纯度，在25°C时观察到朗道普拉西克比为2.3。在10.6 ~ l s的时间范围内得到了光散射弛豫函数，弛豫函数的形状随着温度向玻璃化转变而变宽。利用Kohlrausch-Williams-Watts (KWW)函数对结果进行定量分析，得到平均松弛时间和宽度参数β。根据目测，宽度参数在温度区间内从0.43下降到0.21。平均弛豫时间随温度变化的方式与先前的PHMA中玻璃橡胶初级弛豫的力学研究一致。松弛函数也根据松弛速率G(T)的分布进行了分析。计算出的分布在所有温度下均为单峰分布。由G(T)得到的平均弛豫时间与KWW分析结果一致，随着样品冷却，弛豫时间的分布形状变宽。G(T)达到最大值的速率与相应的PHMA最大介电损耗频率具有良好的相关性。这两个量的温度依赖性可以用21 Kcal/mol的阿伦尼乌斯活化能再现。PHMA在玻璃化转变附近的分子动力学的一致图像需要一个强烈的二次弛豫过程，其温度依赖性与初次玻璃橡胶弛豫不同。本研究结果表明，聚甲基丙烯酸烷基酯的行为与其他聚甲基丙烯酸烷基酯相似。
{"title":"Photon correlation spectroscopy of bulk poly(n‐hexyl methacrylate) near the glass transition","authors":"Y. Hwang, G. Patterson, J. R. Stevens","doi":"10.1002/(SICI)1099-0488(199610)34:14<2291::AID-POLB1>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0488(199610)34:14<2291::AID-POLB1>3.0.CO;2-#","url":null,"abstract":"Slowly relaxing longitudinal density fluctuations in an optically perfect sample of bulk poly(n-hexyl methacrylate) (PHMA) have been studied by photon correlation spectroscopy in the temperature range 10-36°C. The glass transition temperature for this sample was in the temperature range 10-36°C. The glass transition temperature for this sample was measured to be T g = -3°C by differential scanning calorimetry. The optical purity of the sample was verified by Rayleigh Brillouin spectroscopy and the Landau Placzek ratio was observed to be 2.3 at 25°C. Light-scattering relaxation functions were obtained over the time range 10 6 -l s. The shape of the relaxation functions broadened as the temperature was lowered towards the glass transition. Quantitative analysis of the results was carried out using the Kohlrausch-Williams-Watts (KWW) function to obtain average relaxation times , and width parameters, β. The width parameter decreased from 0.43 to 0.21 over the temperature interval, as suggested by visual inspection. Average relaxation times shifted with temperature in a manner consistent with previous mechanical studies of the primary glass-rubber relaxation in PHMA. The relaxation functions were also analyzed in terms of a distribution of relaxation rates, G(T). The calculated distributions were unimodal at all temperatures. The average relaxation times obtained from G(T) were in agreement with the KWW analysis, and the shape of the distribution broadened as the sample was cooled. The rate at which G(T) displayed a maximum correlated well with the corresponding frequency of maximum dielectric loss for PHMA. The temperature dependence of these two quantities could be reproduced with an Arrhenius activation energy of 21 Kcal/mol. A consistent picture of the molecular dynamics of PHMA near the glass transition requires a strong secondary relaxation process with a different temperature dependence from the primary glass-rubber relaxation. The present results suggest that the behavior of PHMA is similar to the other poly(alkyl methacrylates).","PeriodicalId":16853,"journal":{"name":"Journal of Polymer Science. Part B, Polymer Physics","volume":"1 1","pages":"2291-2305"},"PeriodicalIF":0.0,"publicationDate":"1996-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90695339","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}
Pub Date : 1996-09-15DOI: 10.1002/(SICI)1099-0488(19960915)34:12<2067::AID-POLB12>3.0.CO;2-#
J. Ramos, J. Mano, D. Lacey, G. Nestor
The molecular relaxation mechanisms in the glass transition region and in the liquid crystalline phase exhibited by two side-chain liquid crystalline polysiloxanes [Si(Me) 2 O] x [Si(Me)(R)O] y (R= (CH 2 ) 8 OPhCOOPh(Me)(CN) have been studied by Thermally Stimulated Discharge Currents. These results were compared with those previously obtained by dielectric relaxation spectroscopy. It was observed that two relaxation mechanisms were present in the liquid crystalline phase, and we suggest that these might correspond to the motions of the mesogenic moieties in the liquid crystalline phase.
用热激发放电电流研究了两种侧链液晶聚硅氧烷[Si(Me) 2o] x [Si(Me)(R)O] y (R= (CH 2) 8 OPhCOOPh(Me)(CN)在玻璃过渡区和液晶相中的分子弛豫机制。这些结果与先前用介电弛豫光谱得到的结果进行了比较。观察到液晶相中存在两种弛豫机制，我们认为这可能与液晶相中介生部分的运动相对应。
{"title":"Dipolar relaxations in the glass transition region and in the liquid crystalline phase of two side‐chain liquid crystalline polysiloxanes","authors":"J. Ramos, J. Mano, D. Lacey, G. Nestor","doi":"10.1002/(SICI)1099-0488(19960915)34:12<2067::AID-POLB12>3.0.CO;2-#","DOIUrl":"https://doi.org/10.1002/(SICI)1099-0488(19960915)34:12<2067::AID-POLB12>3.0.CO;2-#","url":null,"abstract":"The molecular relaxation mechanisms in the glass transition region and in the liquid crystalline phase exhibited by two side-chain liquid crystalline polysiloxanes [Si(Me) 2 O] x [Si(Me)(R)O] y (R= (CH 2 ) 8 OPhCOOPh(Me)(CN) have been studied by Thermally Stimulated Discharge Currents. These results were compared with those previously obtained by dielectric relaxation spectroscopy. It was observed that two relaxation mechanisms were present in the liquid crystalline phase, and we suggest that these might correspond to the motions of the mesogenic moieties in the liquid crystalline phase.","PeriodicalId":16853,"journal":{"name":"Journal of Polymer Science. Part B, Polymer Physics","volume":"121 1","pages":"2067-2075"},"PeriodicalIF":0.0,"publicationDate":"1996-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73596802","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}
Partial table of contents: POLYMER CHEMISTRY. Intramolecular Reactions in Vinyl Polymers as a Means of Investigation of the Propagation Step (E. Merz, et al.). Relative Reactivities in Vinyl Copolymerization (T. Alfrey & C. Price). Commentary: Reflections on "Recent Developments in Polymerization by an Alternating Intra-Intermolecular Mechanism" (G. Butler). Commentary: Relections on "General Theory of Stationary Random Sequences with Applications to the Tacticity of Polymers" (B. Coleman & T. Fox). Aromatic Polypyromellitimides from Aromatic Polyamic Acids (C. Sroog, et al.). Liquid Crystal Polymers. I. Preparation and Properties of p-Hydroxybenzoic Acid Copolyesters (W. Jackson & H. Kuhfuss). Photoinitiated Cationic Polymerization with Triarylsulfonium Salts (J. Crivello & J. Lam). POLYMER PHYSICS. Simple Presentation of Network Theory of Rubber, with a Discussion of Other Theories (H. James & E. Guth). The Melting Points of Chain Polymers (C. Bunn). Theory of the Interface between Immiscible Polymers (E. Helfand & Y. Tagami). Crazing and Shear Deformation in Crosslinked Polystyrene (C. Henkee & E. Kramer).
部分目录:高分子化学。乙烯基聚合物中的分子内反应作为一种研究繁殖步骤的手段(E. Merz, et al.)。乙烯基共聚的相对反应(T. Alfrey & C. Price)。评论:反思“通过交替的分子间机制聚合的最新发展”(G.巴特勒)。评论:关于“平稳随机序列的一般理论及其在聚合物战术中的应用”的反思(B. Coleman & T. Fox)。从芳香族聚酰胺酸(C. Sroog，等)中提取芳香族聚酰亚胺。液晶聚合物。1 .对羟基苯甲酸共聚酯的制备及其性能(W. Jackson & H. Kuhfuss)。三芳基磺酸盐的光引发阳离子聚合(J. Crivello & J. Lam)。高分子物理。简单介绍橡胶网络理论，并讨论其他理论(H. James & E. Guth)。链式聚合物的熔点(C. Bunn)。非混相聚合物界面理论(E. Helfand & Y. Tagami)。交联聚苯乙烯中的裂纹和剪切变形(C. Henkee & E. Kramer)。
{"title":"A Half-Century of the Journal-of-Polymer-Science","authors":"Pearce Em, M. Sawamoto, Tirrell Da, Amis Ej","doi":"10.5860/choice.35-3307","DOIUrl":"https://doi.org/10.5860/choice.35-3307","url":null,"abstract":"Partial table of contents: POLYMER CHEMISTRY. Intramolecular Reactions in Vinyl Polymers as a Means of Investigation of the Propagation Step (E. Merz, et al.). Relative Reactivities in Vinyl Copolymerization (T. Alfrey & C. Price). Commentary: Reflections on \"Recent Developments in Polymerization by an Alternating Intra-Intermolecular Mechanism\" (G. Butler). Commentary: Relections on \"General Theory of Stationary Random Sequences with Applications to the Tacticity of Polymers\" (B. Coleman & T. Fox). Aromatic Polypyromellitimides from Aromatic Polyamic Acids (C. Sroog, et al.). Liquid Crystal Polymers. I. Preparation and Properties of p-Hydroxybenzoic Acid Copolyesters (W. Jackson & H. Kuhfuss). Photoinitiated Cationic Polymerization with Triarylsulfonium Salts (J. Crivello & J. Lam). POLYMER PHYSICS. Simple Presentation of Network Theory of Rubber, with a Discussion of Other Theories (H. James & E. Guth). The Melting Points of Chain Polymers (C. Bunn). Theory of the Interface between Immiscible Polymers (E. Helfand & Y. Tagami). Crazing and Shear Deformation in Crosslinked Polystyrene (C. Henkee & E. Kramer).","PeriodicalId":16853,"journal":{"name":"Journal of Polymer Science. Part B, Polymer Physics","volume":"85 1","pages":"591-591"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79687452","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}
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