间规聚苯乙烯的多晶型和结晶行为概述

综述间规聚苯乙烯四种稳定的晶型（α、β、δ和γ）结构特点及各种晶型的制备方法。详述间规聚苯乙烯结晶和熔融行为等方面的研究进展。     

间规聚苯乙烯的同质多晶现象

间规聚苯乙烯具有复杂的同质多晶现象，有α，β，γ，δ四种晶型和两种介晶型。本文综述了间规聚苯乙烯的晶体结构、晶型转变以及其结晶和熔融行为等方面的研究进展。     

B链羧端去三肽(B28～B30)胰岛素晶体结构

采用悬滴气相扩散法，获得了Ｂ链羧端去三肽胰岛素３种晶型的单晶体，其中 晶型１属于Ｐ２_1空间群，晶胞参数为ａ＝４．７７ ｎｍ，ｂ＝６．１９ ｎｍ，ｃ＝６．１２ ｎｍ，β＝１１０．３°；晶 型２属于Ｐ４_１２２或Ｐ４_３２２空间群，晶胞参数为ａ＝ ６．４５ ｎｍ， ｃ＝ １２．０７ ｎｍ；晶型３属于 Ｐ２_１２_１２_１空间群，晶胞参数为 ａ＝ ４．９８ ｎｍ， ｂ＝ ５．１６ ｎｍ， ｃ＝ １０．０６ ｎｍ．采用分子置换法， 测定并精化了 Ｂ链羧端去三肽胰岛素晶型１的 ０．２３ ｎｍ分辨率晶体结构．最终模型的 Ｒ 因子为１８．８％，键长和键角与标准键长和键角的均方根偏差分别为０．００１５ ｎｍ和３．３°． 晶体结构的结果表明， Ｂ链羧瑞去三肽胰岛素失去了对缔合有重要作用的 Ｂ２８ Ｐｒｏ后， 虽然仍能形成六聚体，但表现出比天然胰岛素更易解聚的结构变化。     

K_3Sb_3P_2O_（14）·5H_2O的水热合成与表征

利用水热晶化法合成了磷锑酸钾Ｋ３Ｓｂ３Ｐ２Ｏ１４·５Ｈ２Ｏ，并通过ＸＲＤ、３１ＰＭＡＳＮＭＲ、ＩＲ、ＤＴＡ－ＴＧ及组成分析等多种手段对其进行了表征。该化合物属六方晶系，晶胞参数为：ａ＝０．７１３７７ｎｍ，ｂ＝０．７１３７７ｎｍ，ｃ＝３．０８０４７ｎｍ，α＝９０°，β＝９０°，γ＝１２０°，具有层状结构，钾离子具有可交换性。     

新钽酸盐Ba_3TiTa_4O_(15)的结构与介电性能

在 ＢａＯ－Ｔａ２Ｏ５系统通过掺Ｔｉ４＋合成了新钽酸盐 Ｂａ３ＴｉＴａ４Ｏ１５,用粉晶ＸＲＤ对其结构进行了分析,并测试了其烧结体的介电特性．结果表明：Ｂａ３ＴｉＴａ４Ｏ１５在室温下属于填满型四方钨青铜结构,晶胞参数α＝１．２５６ ２７（６）ｎｍ,ｃ＝０．３９５ ８６（４）ｎｍ;Ｂａ３ＴｉＴａ４Ｏ１５在－３５℃从铁电相转变为顺电相     

填充间规聚苯乙烯的结晶

间规聚苯乙烯(sPS)性能取决于结晶行为与晶型,sPS结晶行为与形态有许多研究.本文重点综述了黏土、纳米CaCO3、滑石粉、SiO2、Mg(OH)2、TiO2,和成核剂等对sPS结晶行为、结晶形态、熔融特性与晶型的影响.认为sPS结晶行为与晶型取决于成核能垒.成核能垒低,有利于形成α-晶.熔融温度提高,提高成核能垒,有利于形成β-晶.填料加入阻碍sPS结晶成核,提高成核能垒,有利于形成β-晶.成核剂加入,降低成核能垒,有利于形成α-晶.     

双核钨氧柠檬酸配合物K_6[W_2O_5(cit)_2]·6H_2O的合成及晶体结构

标题化合物是通过四硫代钨酸铵和柠檬酸钾反应而得。用ＩＲ、ＸＰＳ、元素分析进行了结构表征，Ｘ－ｒａｙ结构测定进一步肯定了以上结论。该晶体为三斜晶系，Ｐ１空间群，晶胞参数为：ａ＝０．８５１１１（９）ｎｍ，ｂ＝０．９７８４（１０）ｎｍ，ｃ＝１．０８２（１１）ｎｍ，α＝１１４．８５（１２）°，β＝１０６．５８（１１）°，γ＝９８．８９（１０）°，Ｚ＝１，Ｖ＝０．７４３６（１３）ｎｍ３，Ｄｃ＝２．５９４ｇ／ｃｍ３，Ｆ（０００）＝５５４，μ＝８６．６１ｃｍ－１，一致性因子Ｒ＝０．０７５，ＷＲ２＝０．１８８９。     

Y2O2S：Eu^3＋荧光体的微波热效应合成和发光性能

用微波热效应法合成Ｙ２Ｏ３Ｓ：Ｅｕ＾３＋粉晶荧光体，经Ｘ射线粉末衍射分析确证其为六方晶系，计算得到其晶胞参数ａ＝０．３７８５ｎｍ，ｃ＝０．６５９０ｎｍ。激发光谱峰呈宽带状，最大激发光谱峰λｅｘ＝２６１ｎｍ，最大发射光谱峰λｅｎ＝６２６ｎｍ，其次还有５９５、６１７和７０６ｎｍ，归属为Ｅｕ＾３＋离子的＾５Ｄ０－＾７ＦＪ特征发射。     

NH4ZnPO4的非水合成与晶体结构

从非水体系中制得ＮＨ４ＺｎＰＯ４单晶，并用Ｘ线测定了晶体结构；晶体属六方晶系，Ｐ６３空间群，晶胞参数；ａ＝１．０６８８（２）ｎｍ，ｃ＝８７０６（２）ｎｍ，Ｚ＝８，Ｄｃ＝２．７５１ｇ．ｃｍ＾－３，结构中的锌和磷均为四面体本位，且严格交替排列，无Ｚｎ－Ｏ－Ｚｎ和Ｐ－Ｏ－Ｐ联结方式。     

含质子柠檬酸氧钒（V）配合物中间体的合成和晶体结构

合成了含质子柠檬酸氧钒（Ｖ）配合物中间体ＮａＫ３［ＶＯ２（Ｈｃｉｔ）］２·７Ｈ２Ｏ，用红外光谱和Ｘ射线衍射进行了结构表征。结果表明：晶体属单斜晶系，Ｐ２１／ｎ空间群。晶胞参数ａ＝１．１２５８（２）ｎｍ，ｂ＝１．５７７４（３）ｎｍ，ｃ＝１６５５９（１）ｎｍ，β＝９８．５６８（９）°，Ｖ＝２．９０８（１）ｎｍ＾３，Ｚ＝４，Ｄｃ＝１．８５１ｇ·ｃｍ＾－３，Ｆ（０００）＝１６４０，μ（Ｃｕ Ｋα）＝１０４     

不同后处理条件下聚萘二甲酸乙二酯纤维的结构变化

对不同纺速下制得的聚萘二甲酸乙二酯 (PEN)初生纤维进行了冷拉伸、定长热处理和热拉伸等后处理 .通过WAXS、DSC等测试研究了纤维中结构变化与后处理条件之间的关系 .结果表明 ,较低纺速下所制得的无定形初生纤维在低于Tg 温度下的冷拉伸时发生了应力诱导结晶 ,纤维中生成了α晶体 .同样的初生纤维在定长热处理过程中直至 2 0 0℃仍保持无定形结构 .这些结果说明施加应力相对于升高温度对于α晶体的生成更为重要 .而热拉伸样品中结晶结构的形成与初生纤维的结构有很大关系 ,低纺速下无定形初生纤维在热拉伸后形成α晶体 ,而高纺速下主要含有 β晶体的初生纤维经热拉伸后 β晶体会部分转变为α晶体 ,且 β晶转变为α晶的难易程度取决于初生纤维中 β晶的完善程度 ,初生纤维中 β晶越完善 ,热拉伸时 β晶体越不易转变为α晶体     

细旦尼龙6纤维加工过程中的晶型转化行为

通过引入富镧稀土化合物等添加剂,成功实现了细旦尼龙6纤维的熔融纺丝．考察了在纺丝卷绕成型以及牵伸过程中尼龙6纤维的晶型变化．借助XRD和FT－IR等研究手段,发现尼龙6在纺丝过程中可以生成亚稳态的B晶型晶体．这种β晶型经过沸水处理后很容易转化为α晶型,而γ晶型尼龙6经沸水处理后不发生相转变．因此可以通过沸水热处理的方法区分尼龙6的β和γ晶型．在纤维的卷绕过程中,当熔体拉伸倍数较高时,尼龙6可能产生β晶型;当熔体拉伸倍数较低时,则以γ晶型为主．在纤维的牵伸过程中,γ晶型经过β晶型中间态向α晶型相转变．上述结果对于指导改进细旦尼龙6纤维的加工工艺以及提高产品性能有指导意义．     

Vibration-induced change of crystal structure in isotactic polypropylene and its improved mechanical properties

In order to understand the formation of different crystal structures and improve the mechanical properties of isotactic polypropylene (iPP), melt vibration technology, which generally includes shear vibration and hydrostatic pressure vibration, was used to induce the change of crystal structure of iPP. iPP forms α crystal structure in traditional injection molding. Through melt vibration, crystal orientated and its size became smaller, and a change of crystal structure of iPP from α form to β form and γ form was achieved. Therefore, the mechanical properties of iPP were improved. At high melting temperature (230 °C), only β form can be induced. At low melting temperature (190 °C), either β form or γ form can be induced, depending on the combination of frequency and vibration pressure. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2385–2390, 2004     

聚己内酯在α和β松弛过程中的微观结构演化

利用X射线小角散射和广角衍射技术,研究了晶胞体积、散射积分不变量Q和长周期在α和β松弛过程中的变化,发现晶体结构的演变与非晶区的α和β松弛有较强的关联性,而且不同相区在高分子松弛变化过程中具有协同性。结果表明,晶胞体积变化在高分子链段运动的α松弛和主链基团扭转的β松弛的激活和冻结过程中是可逆的。由于系带分子的β松弛行为被冻结或激活而引起晶胞体积收缩系数的改变,从而导致晶胞体积在-90℃出现突变。散射积分不变量Q在整个过程中也是可逆变化的,在可逆过程中发生的突变主要是由于α松弛的冻结或激活引起的。因为样品在降温过程中发生插入式的结晶模式,在升温过程中这些二次结晶形成的片晶需要在较高温度下才能熔化,所以在整个过程中长周期变化不可逆。     

Analysis of crystallization behavior and crystal modifications of poly(butylene‐2,6‐naphthalene dicarboxylate)

Information on the crystalline structure and the properties of poly(butylene‐2,6‐naphthalene dicarboxylate) (PBN) has not been well reported until now, but it is known that there are two different crystal modifications in PBN, as follows: one is formed in isotropic samples by annealing (α form); another appears by annealing with tension (β form). The relation between the crystal modifications and the kinetics of isothermal crystallization for PBN was investigated using in‐situ Fourier transform infrared spectroscopy (FTIR) and wide‐angle X‐ray diffraction (WAXD). The melting behavior of each crystalline form was also studied by means of FTIR and differential scanning calorimetry (DSC) measurements. From the analysis of the melt‐crystallized PBN specimens, the two crystalline forms coexisted in the isotropic samples melt‐crystallized at 230°C, but only the α crystal modification was observed in the films annealed at lower temperatures. In addition, it was revealed that, at 230°C, the β modification was formed only in the primary crystallization process. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 561–574, 1999     

磺化间规聚苯乙烯的表征

间规聚苯乙烯(sPS)是一种新型结晶性工程塑料,熔点达270℃,具有结晶速度快、耐热性好、耐化学腐蚀性优良等特点,可广泛用于汽车、电子、机械等行业,极具开发意义,但是由于sPS脆性大,抗冲击性差,故通过化学改性在sPS的苯环上引入极性基团,用于制成共混合金与复合材料,是提高材料韧性,开拓sPS用途的重要途径。     

Diffusion of oxygen and carbon dioxide in thermally crystallized syndiotactic polystyrene

The diffusion, solubility, and permeability behavior of oxygen and carbon dioxide were studied in amorphous and semicrystalline syndiotactic polystyrene (s‐PS). The crystallinity was induced in s‐PS by crystallization from the melt and cold crystallization. Crystalline s‐PS exhibited very different gas permeation behavior depending on the crystallization conditions. The behavior was attributed to the formation of different isomorphic crystalline forms in the solid‐state structure of this polymer. The β crystalline form was virtually impermeable for the transport of oxygen and carbon dioxide. In contrast, the α crystalline form was highly permeable for the transport of oxygen and carbon dioxide. High gas permeability of the α crystals was attributed to the loose crystalline structure of this crystalline form containing nanochannels oriented parallel to the polymer chain direction. A model describing the diffusion and permeability of gas molecules in the composite permeation medium, consisting of the amorphous matrix and the dispersed crystalline phase with nanochannels, was proposed. Cold crystallization of s‐PS led to the formation of a complex ordered phase and resulted in complex permeation behavior. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2519–2538, 2001     

Crystalline behaviors and phase transition during the manufacture of fine denier PA6 fibers

Recently we have successfully produced fine denier PA6 fibers by using additives containing lanthanide compounds. Meanwhile, crystallization and phase transition of PA6 fibers during spinning and drawing processes were investigated. During the spinning process, β phase crystal could be obtained in as-spun PA6 fibers which were produced with relatively high melt draw ratio, while γ phase crystal predominated when the melt draw ratio was relatively low. β phase crystal, whose behaviors are similar with those of γ phase by FT-IR and XRD characterization, could be transformed to α form easily when PA6 fibers are immersed in boiling water. However, γ phase crystal of PA6 remains unchanged in boiling water. Thus, β and γ phase crystals of PA6 can be differentiated by the crystalline behaviors of PA6 fibers after treatment in boiling water. Further experiments demonstrate that the β phase can also be produced during a drawing process where a phase transformation from γ to α occurs. In other words, β phase may act as an intermediate state during the phase transformation.     

淬火温度对聚偏氟乙烯形态结构的影响

用透射电子显微镜（ＴＥＭ）和傅里叶交换红外光谱（ＦＴＩＲ）等方法研究了结晶温度对聚偏氟乙烯（ＰＶＦ２）晶相结构的影响．结果表明，从ＰＶＦ２熔体高速淬火到较低温度等温结晶可直接生成β相结晶，临界淬火温度为３０℃．淬火温度在４０—７０℃时，α和β相共存．当淬火温度较高时（８０—１５０℃），生成α相结晶．在淬火温度高于１６５℃时，则得到ＰＶＦ２的γ相结晶．在临界温度以下淬火的ＰＶＦ２薄膜含有β相微晶，而高于临界淬火温度时则生成α相或γ相的片晶或球晶结构．     

Two‐phase crystallization kinetics of syndiotactic polystyrene

In this work, a two phase crystallization model based on the extension of the Kolmogoroff approach was proposed and verified by comparison with experimental isothermal and nonisothermal crystallization data of Syndiotactic Polystyrene (sPS) in a very wide range of cooling rates, up to 600 °C/s. To investigate the effects of high cooling rate on the sPS crystalline structure, a homemade apparatus was adopted. The morphology in solid samples was analyzed by densitometry, IR spectroscopy, and X‐rays diffraction. The coupling of these techniques allows the determination of the fractions of different crystalline phases. In agreement with melt‐crystallization studies of sPS proposed by different authors, either α and β forms could be produced depending on the thermal history of the sample. Results show that the stable β form is favored for specimens solidified at higher temperature or under low cooling rates, whereas α and mesomorphic forms are favoured at low temperature or high cooling rates. The proposed multiphase crystallization kinetics model successfully described all the range of experimental data. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1757–1766, 2010