Crystal Morphology and Phase Identification in Poly(aryl ether ketone)s and Their Copolymers. 3. Polymorphism in a Polymer Containing Alternated Terephthalic Acid and Isophthalic Acid Isomers
Crystal Morphology and Phase Identification in Poly(aryl ether ketone)s and Their Copolymers. 3. Polymorphism in a Polymer Containing Alternated Terephthalic Acid and Isophthalic Acid Isomers
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聚（芳基醚酮）及其共聚物的晶体形态和相鉴定。
DOI：
10.1021/ma00110a030
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发表时间：
1995
期刊：
影响因子：
5.5
通讯作者：
K. Gardner
中科院分区：
文献类型：
--
作者：
R. Ho;Stephen Z. D. Cheng;B. Hsiao;K. Gardner
用透射电镜、电子衍射（艾德）、广角X射线衍射（WAXD）和差示扫描量热法（DSC）研究了含交替对苯二甲酸（T）和间苯二甲酸（I）连接的聚（醚酮酮）[PEKK（T/I）]的结晶结构和形态。当聚合物在高温（在310° C和高于310°C）下结晶时，仅发现一个正交晶体晶胞（晶型I），并且晶体尺寸为a=0.778 nm，B=0.610 nm，和c=3.113 nm。在低于200 ℃的结晶温度下，形成另一个正交晶体晶胞（晶型II），其尺寸为a=0.417 nm，B=1.108 nm，和c=3.113 nm。即使在该低温范围内，II型也总是与I型共存，除了溶剂诱导结晶的情况。在200 - 300°C的温度范围内可能存在新的晶型（III型），通常与I型共存。这种形式还具有正交晶胞，其尺寸为a=0.641 nm，B=0.610 nm，c=3.504 nm。从II型转化为I型和III型需要熔融和重结晶。在PEKK（T/I）中可以观察到形状相对规则的片状晶体
Crystal structures and morphology of a polymer containing alternated terephthalic acid (T) and isophthalic acid (I) linked phenylene units in poly(ether ketone ketone) [PEKK(T/I)] have been investigated via TEM, electron diffraction (ED), WAXD, and DSC experiments. When the polymer is crystallized at high temperatures (at and above 310°C), only one orthorhombic crystal unit cell (form I) is found, and the crystal dimensions are a=0.778 nm, b=0.610 nm, and c=3.113 nm. At the crystallization temperature below 200°C, another orthorhombic crystal unit cell (form II) forms, having the dimensions of a=0.417 nm, b=1.108 nm, and c=3.113 nm. Even at this low-temperature range, form II always coexists with form I except in the case of solvent-induced crystallization. A possibility of the existence of a new form (form III) is identified in a temperature range between 200 and 300°C, and usually coexists with form I. This form also possesses an orthorhombic unit cell with dimensions of a=0.641 nm, b=0.610 nm, and c=3.504 nm. Transformations from form II to both forms I and III require melting and recrystallization. Relatively regular-shaped lamellar crystals in PEKK(T/I) can be observed