Three-dimensional morphology of PVDF single crystals forming banded spherulites

被引:86
作者
Toda, A [1 ]
Arita, T [1 ]
Hikosaka, M [1 ]
机构
[1] Hiroshima Univ, Fac Integrated Arts & Sci, Higashihiroshima 7398521, Japan
基金
日本学术振兴会;
关键词
spherulite; banding; poly(vinylidene fluoride);
D O I
10.1016/S0032-3861(00)00446-8
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
We have examined the morphology of poly(vinylidene fluoride) (PVDF) single crystals grown from melt and from blends with poly(ethyl acrylate) (PEA), PVDF/PEA = 0.5/99.5 and 30/70 by weight. The single crystals, of relatively higher molecular weight, were grown isothermally in the temperature range where banded spherulites are formed with sufficient crystallization time. The crystals were extracted by dissolving amorphous PEA and PVDF crystals formed on quenching. The three-dimensional morphology of the single crystals was examined by transmission electron microscopy (bright field, dark held and diffraction) with a tilting stage. For all cases, the tilting of chains (similar to 25-27 degrees) to the fold surface has been confirmed. The three-dimensional shape of all the crystals was chair type for the 30/70 blend and pure PVDF. In chair crystals, spiral terraces keep the handedness in each growth direction. From these evidence, it is proposed that the chair crystals with consecutive creation of spiral terraces of the same sense are responsible for the twisting relationship between crystallites in the radial direction of the banded spherulites. (C) 2000 Published by Elsevier Science Ltd.
引用
收藏
页码:2223 / 2233
页数:11
相关论文
共 33 条
[1]   SOME NEW HABIT FEATURES IN CRYSTALS OF LONG CHAIN COMPOUNDS .4. FOLD SURFACE GEOMETRY OF MONOLAYER POLYETHYLENE CRYSTALS AND ITS RELEVANCE TO FOLD PACKING AND CRYSTAL GROWTH [J].
BASSETT, DC ;
KELLER, A ;
FRANK, FC .
PHILOSOPHICAL MAGAZINE, 1963, 8 (94) :1753-&
[2]   ON THE MORPHOLOGY OF MELT-CRYSTALLIZED POLYETHYLENE .3. SPHERULITIC ORGANIZATION [J].
BASSETT, DC ;
HODGE, AM .
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 1981, 377 (1768) :61-&
[3]   ON THE MORPHOLOGY OF MELT-CRYSTALLIZED POLYETHYLENE .1. LAMELLAR PROFILES [J].
BASSETT, DC ;
HODGE, AM .
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL AND PHYSICAL SCIENCES, 1981, 377 (1768) :25-+
[4]  
BASSETT DC, 1980, PRINCIPLES POLYM MOR
[5]   THE MORPHOLOGY OF POLY(VINYLIDENE FLUORIDE) CRYSTALLIZED FROM BLENDS OF POLY(VINYLIDENE FLUORIDE) AND POLY(ETHYL ACRYLATE) [J].
BRIBER, RM ;
KHOURY, F .
JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS, 1993, 31 (10) :1253-1272
[6]  
GEIL PH, 1963, POLYM SINGLE CRYSTAL
[7]   THE OPTICAL BEHAVIOR OF SPHERULITES IN CRYSTALLINE POLYMERS .2. THE GROWTH AND STRUCTURE OF THE SPHERULITES [J].
KEITH, HD ;
PADDEN, FJ .
JOURNAL OF POLYMER SCIENCE, 1959, 39 (135) :123-138
[8]   ASYMMETRIES OF HABIT IN POLYETHYLENE CRYSTALS GROWN FROM THE MELT [J].
KEITH, HD ;
PADDEN, FJ ;
LOTZ, B ;
WITTMANN, JC .
MACROMOLECULES, 1989, 22 (05) :2230-2238
[9]   Banding in polyethylene and other spherulites [J].
Keith, HD ;
Padden, FJ .
MACROMOLECULES, 1996, 29 (24) :7776-7786
[10]   TWISTING ORIENTATION AND THE ROLE OF TRANSIENT STATES IN POLYMER CRYSTALLIZATION [J].
KEITH, HD ;
PADDEN, FJ .
POLYMER, 1984, 25 (01) :28-42