尼龙1010非等温结晶动力学与机理研究

尼龙１０１０非等温结晶动力学与机理研究朱诚身，王经武，李卓美（郑州大学材料工程系郑州４５００５２）（中山大学高分子研究所广州５１０２７５）关键词尼龙１０１０，非等温结晶动力学，结晶机理，动力学结晶能力尼龙１０１０的结晶动力学，无论是等温还是非等温，研...     

混合液晶与尼龙1010三元共混物的研究

采用ＤＣＳ、ＰＯＭ、ＳＥＭ及力学性能测试，研究了不同对羟基苯甲醛和对苯二甲酸乙二醇酯含量的液晶共聚酯ＰＥＴ４０／ＰＨＢ６０（ＬＣＰ１）和ＰＥＴ３０／ＰＨＢ７０（ＬＣＰ２）的共混物与尼龙１０１０为基体的三元混体系。结果表明，液晶共混物的力学性能比单组分有明显提高，通过改变混合液晶中两组分的含量可调节其加工温度与粘度，从而满足了与尼龙１０１０共混的加工窗口要求。混合液晶的加入对尼龙１０１０的结晶与熔融     

不同分子量初生态尼龙1010的熔融

利用ＤＳＣ方法研究了熔体聚合不同分子量初生态尼龙１０１０样品的熔融，发现随分子量增大，熔点有极大值，高规整性晶体的量也呈极大值，且两者峰值相同，结晶度则逐渐减小，熔融热，熔融熵也逐渐减小，其原因主要高规整度晶体量减少所致。     

聚醚酮酮的合成、表征与结晶行为

聚醚酮酮的合成、表征与结晶行为＊王军佐郑玉斌柯扬船于冬宏＊＊吴忠文（吉林大学化学系长春１３００２３）关键词聚醚酮酮，结晶结构，低温熔融峰，热处理聚醚醚酮８０年代初由英国ＩＣＩ公司商品化，由于其优异的性能，已在宇航、军工、核能等领域得到了广泛的应用，聚...     

尼龙－1010的聚集态结构

用ＷＡＸＤ、ＤＳＣ、方差－范围函数．密度测量等方法，研究了经不同热处理的尼龙－１０１０的聚集态结构．发现退火处理更有利于尼龙－１０１０结晶的生成和稳定，且尼龙－１０１０的结晶，有一个最佳的热处理温度．在该温度附近，尼龙－１０１０的结晶度和微晶尺寸里最大值．     

尼龙－1010的聚集态结构

用ＷＡＸＤ，ＤＳＣ，方差－范围函数，密度测量等方法，研究了经不同热处理的尼龙－１０１０的聚集态结构。发现退火处理更有利于尼龙－１０１０结晶的生成和稳定，且尼龙－１０１０的结晶，有一个最佳的热处理温度，在该温度附近，尼龙－１０１０的结晶度和不见得昌尺寸呈最大值。     

尼龙1010分别与未接枝和接枝马来酸酐的高抗冲聚苯乙烯的共混体系研究

研究了尼龙１０１０（ Ｐ Ａ１０１０） 与高抗冲聚苯乙烯（ Ｈ Ｉ Ｐ Ｓ） 及马来酸酐官能化的 Ｈ Ｉ Ｐ Ｓ（ Ｈ Ｉ Ｐ Ｓ ｇ Ｍ Ａ） 间的相互作用,利用 Ｄ Ｓ Ｃ, Ｄ Ｍ Ａ, Ｓ Ｅ Ｍ 及拉伸测试等方法研究了不同组成比的共混物 Ｐ Ａ１０１０／ Ｈ Ｉ Ｐ Ｓ 与 Ｐ Ａ１０１０／ Ｈ Ｉ Ｐ Ｓ ｇ Ｍ Ａ 的结晶、玻璃化转变、形态及力学性能．结果表明 Ｈ Ｉ Ｐ Ｓ 与 Ｐ Ａ１０１０ 虽然结构相差甚远,但两者之间仍存在着一定的相互作用;而 Ｈ Ｉ Ｐ Ｓ ｇ Ｍ Ａ 可使 Ｐ Ａ１０１０ 的低温熔融峰变小,当 Ｈ Ｉ Ｐ Ｓ ｇ Ｍ Ａ 的含量≤５０ ％ 时,随着其含量的增加,共混物中 Ｐ Ａ１０１０ 的结晶温度升高;当含量＞ ５０ ％ 时, Ｐ Ａ１０１０ 发生分级结晶行为,其结晶温度由原来的１７８ ℃降至８３ ℃,同时 Ｈ Ｉ Ｐ Ｓ ｇ Ｍ Ａ 与 Ｐ Ａ１０１０ 间的相互作用变大, Ｄ Ｍ Ａ 谱上有明显的新的松驰峰． Ｐ Ａ１０１０／ Ｈ Ｉ Ｐ Ｓ ｇ Ｍ Ａ 共混体系的拉伸性能要优于相同组成的 Ｐ Ａ１０１０／ Ｈ Ｉ Ｐ Ｓ 体系．以上现象主要是由于 Ｈ Ｉ Ｐ Ｓ ｇ Ｍ Ａ 与 Ｐ Ａ１０１０ 中的端胺基发生了化学反应,产生了接枝共聚物 Ｐ Ａ１０１０ ｇ Ｈ Ｉ Ｐ     

刚性粒子增韧尼龙1010体系的研究

采用扫描电镜和动态力学等研究了在磺化聚苯乙烯（ＨＳＰＳ）作用下，尼龙１０１０（ＰＡ１０１０）／聚苯乙烯（ＰＳ）共混物的形态及相容性。结果表明，ＨＳＰＳ的加入显著改善了ＰＳ与ＰＡ１０１０的相容性，加强了界面粘结，使共混物缺口冲击明显提高，实现了ＰＳ增韧ＰＡ１０１０的目标。偏光显微竟结盟表明，ＨＳＰＳ的加入对共混物中ＰＡ１０１０的结晶形态有明显影响，使ＰＡ１０１０球晶细化且不完善。     

热处理对尼龙1010结构影响研究

采用ＷＡＸＤ，ＳＡＸＳ方法研究了热处理对尼龙１０１０聚集态结构的影响．结果表明，在温度为１７５℃左右对样品进行退火处理可获得较完善的结晶．利用Ｗｃ．ｘ~Ｔ关系曲线外推法得到尼龙１０１０样品的Ｔｇ大约为５８℃．根据一维电子密度相关函数法求得了系列样品在所研究条件下的结晶片层厚，过渡层厚，长周期和结晶非晶相间的密度差．得到了不同退火条件尼龙１０１０样品的结晶相密度ρｃ．     

HE－1型催化剂异相聚合乙烯结晶性能研究 Ⅱ．超高分子量PE结晶行为

用小角Ｘ－射线散射，广角Ｘ－射线衍射，差示扫描量热法，研究了ＨＥ－１型钛系催化剂异相聚合超高分子量聚乙烯的稀溶液的结晶和熔融结晶的熔点，熔化热，结晶度，长周期，晶区厚度和非昌区厚度随分子量与结晶温度的关系．并着重讨论了熔融结晶和初生态结晶的不同过程机理．结果表明：ＵＨＭＷＰＥ稀溶液结晶的结晶度（Ｘｃ％），长周期（Ｌ）和晶区厚度（Ｌｃ）与分子量Ｍｗ无关，随结晶温度升高而增加，非晶区厚度（Ｌａ）与分子量和结晶温度均无关，熔点Ｔｍ随分子量增大稍有升高．熔融结晶样品长周期与分子量无关，却和结晶温度和时间有关．其结晶度和晶区厚度随分子量增大而下降，非昌区厚度和熔点均随分子量增大而增大，初生态粉末中没发现长周期，却发现有较高熔点．     

Thermal analysis of the double-melting behavior of poly(L-lactic acid)

The melting and crystallization behavior of poly(L -lactic acid) (PLLA; weight-average molecular weight = 3 × 10⁵) was studied with differential scanning calorimetry (DSC). DSC curves for PLLA samples were obtained at various cooling rates (CRs) from the melt (210 °C). The peak crystallization temperature and the exothermic heat of crystallization determined from the DSC curve decreased almost linearly with increasing log(CR). DSC melting curves for the melt-crystallized samples were obtained at various heating rates (HRs). The double-melting behavior was confirmed by the double endothermic peaks, a high-temperature peak (H) and a low-temperature peak (L), that appeared in the DSC curves at slow HRs for the samples prepared with a slow CR. Peak L increased with increasing HR, whereas peak H decreased. The peak melting temperatures of L and H [T_m(L) and T_m(H)] decreased linearly with log(HR). The appearance region of the double-melting peaks (L and H) was illustrated in a CR–HR map. Peak L decreased with increasing CR, whereas peak H increased. T_m(L) and T_m(H) decreased almost linearly with log(CR). The characteristics of the crystallization and double-melting behavior were explained by the slow rates of crystallization and recrystallization, respectively. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 25–32, 2004     

Multiple melting behavior of poly(butylene succinate). I. Thermal analysis of melt‐crystallized samples

The multiple melting behavior of poly(butylene succinate) (PBSu) was studied with differential scanning calorimetry (DSC). Three different PBSu resins, with molecular weights of 1.1 × 10⁵, 1.8 × 10⁵, and 2.5 × 10⁵, were cooled from the melt (150 °C) at various cooling rates (CRs) ranging from 0.2 to 50 K min^?1. The peak crystallization temperature (T_c) of the DSC curve in the cooling process decreased almost linearly with the logarithm of the CR. DSC melting curves for the melt‐crystallized samples were obtained at 10 K min^?1. Double endothermic peaks, a high‐temperature peak H and a low‐temperature peak L, and an exothermic peak located between them appeared. Peak L decreased with increasing CR, whereas peak H increased. An endothermic shoulder peak appeared at the lower temperature of peak H. The CR dependence of the peak melting temperatures [T_m(L) and T_m(H)], recrystallization temperature (T_re), and heat of fusion (ΔH) was obtained. Their fitting curves were obtained as functions of log(CR). T_m(L), T_re, and ΔH decreased almost linearly with log(CR), whereas T_m(H) was almost constant. Peak H decreased with the molecular weight, whereas peak L increased. It was suggested that the rate of the recrystallization decreased with the molecular weight. T_m(L), T_m(H), T_re, and T_c for the lowest molecular weight sample were lower than those for the others. In contrast, ΔH for the highest molecular weight sample was lower than that for the others. If the molecular weight dependence of the melting temperature for PBSu is similar to that for polyethylene, the results for the molecular weight dependence of PBSu can be explained. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2411–2420, 2002     

Nonisothermal crystallization and melting behavior of a luminescent conjugated polymer,poly(9,9‐dihexylfluorene‐alt‐co‐2,5‐didecyloxy‐1,4‐phenylene)

The nonisothermal crystallization kinetics of a luminescent conjugated polymer, poly(9,9‐dihexylfluorene‐alt‐co‐2,5‐didecyloxy‐1,4‐phenylene) (PF6OC10) with three different molecular weights was investigated by differential scanning calorimetry under different cooling rates from the melt. With increasing molecular weight of PF6OC10, the temperature range of crystallization peak steadily became narrower and shifted to higher temperature region and the crystallization rate increased. It was found that the Ozawa method failed to describe the nonisothermal crystallization behavior of PF6OC10. Although the Avrami method did not effectively describe the nonisothermal crystallization kinetics of PF6OC10 for overall process, it was valid for describing the early stage of crystallization with an Avrami exponent n of about 3. The combined method proposed in our previous report was able to satisfactorily describe the nonisothermal crystallization behavior of PF6OC10. The crystallization activation energies determined by Kissinger, Takhor, and Augis‐Bennett models were comparable. The melting temperature of PF6OC10 increased with increasing molecular weight. For low‐molecular‐weight sample, PF6OC10 showed the characteristic of double melting phenomenon. The interval between the two melting peaks decreased with increasing molecular weight, and only one melting peak was observed for the high‐molecular‐weight sample. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 976–987, 2007     

A calorimetric study of normal high density and ultra-high molecular weight polyethylene blends

The melting and the crystallization of blends of ultra-high molecular weight polyethylene (UHMWPE) and polyethylene high density with normal molecular weight (NMWPE) are investigated by means of differential scanning calorimetry (DSC). Mixing the components at a temperature below the flow temperature of UHMWPE (215 °C) results in segregated melting and crystallization. The segregated melting and crystallization temperatures of both components do not depend on composition of the blend. The extreme enthalpy dependence on blend composition is explained in terms of mutual influence exhibited by the components with respect to each other. It is due to the inner stresses in nonflowing UHMWPE characterized with a lot of entangled tie molecules. Mixing the components above the flow temperature of UHMWPE results in only one peak of melting and crystallization respectively. Complete mixing and probably co-crystallization between the components takes place on mixing NMWPE with flowing UHMWPE.     

尼龙1010结晶与熔融行为的研究

用DSC研究了降温速率R对尼龙10 10结晶与熔融的影响,以及室温(RT)和液氮(LN)骤冷退火样品的熔融.降温时结晶温度随R增大线性降低;T_g以上可完成结晶时结晶度相同;结晶起始温度>181℃生成的晶体有三个熔融峰,对应于环状和放射状球晶的转化与熔融;在181℃和T_g间结晶,无放射球晶转化峰;T_g下有结晶放热峰样品加热时有冷结晶发生.RT未退火样品三个熔融峰,退火温度T_α≥180℃样品两个峰,结晶度C∝T_a;LN未退火样品单一熔融峰,T_a>160℃双峰,T_a≤160℃三峰,低温峰温与C均∝T.     

Effect of molecular weight on the crystalline structure of polytetrafluoroethylene as-polymerized

Melting and crystallization behavior of polytetrafluoroethylene as polymerized in emulsion and suspension is shown to depend on molecular weight. DSC heating curves for virgin PTFE with low molecular weight below 3 × 10⁵ have a single peak, whereas curves for higher molecular weight samples have double peaks. With increasing heating rate the areas of higher melting peaks become larger than the lower melting peaks. The morphology of polymer exhibiting double melting peaks is mainly folded ribbons or granular particles. The phenomenon of double melting is explained on the basis of two different crystalline states which correspond to the “fold regions” and the “linear segments” in a folded ribbon. The melting temperature of virgin PTFE is almost constant at ca. 330°C for molecular weights below 1 × 10⁶, and rises as the molecular weight increases above 1 × 10⁶. The heat of melting of virgin PTFE is nearly independent of molecular weight. On the basis of these results, we propose a model for melting and crystallization of low and high molecular weight PTFE and for the crystal structure.     

Temperature-dependent x-ray small-angle scattering from melt-crystallized polyethylene

The temperature dependence of x-ray small-angle scattering from fractionated linear polyethylene crystallized from the melt was determined experimentally over a range of temperatures from room temperature to the melting point. It was found in general that only the most intense of the several small-angle peaks exhibited a thermally dependent behavior. Below the crystallization temperature this peak increased in intensity with temperature, at constant peak position. Recrystallization was manifest in a discontinuous shift of the peak. During isothermal crystallization, the peak intensity first increased, then decreased, with time. It is concluded from supplementary electron microscopy and from the behavior of the peak that its position reflects the period of stacking of lamellae and that its intensity is controlled primarily by the thickness of the layer separating lamellae. The reversible peak intensity effect is attributed to an entropydriven growth of the interlamellar layer at the expense of the crystalline lamellae. The intensity effects observed during crystallization are associated with the primary and secondary phases of crystallization. Lamellar surface free energies were computed from melting point observations and were found to increase with molecular weight.     

Specific reversible melting of polymers

Temperature‐modulated differential scanning calorimetry can detect a certain amount of reversible latent heat in flexible macromolecules. In short, one can identify a reversible melting in such polymers earlier thought to exhibit only fully irreversible crystallization and melting. Details of the reversible melting of isotactic polypropylene and ethylene‐1‐octene copolymers of low and medium densities have newly been measured and linked to the crystallization, annealing, or melting temperature. It is possible to assign the experimental reversibility of melting to specific crystal fractions that ultimately melt irreversibly at higher temperatures; that is, it is suggested that reversible melting mainly occurs only between the temperatures of their formation and their zero‐entropy‐production melting temperature, at which they change to a melt of the same degree of metastability. This is supported by the almost complete absence of reversibility below the temperature of crystal formation and the observation of a distinct relationship between the amount of irreversibly by annealing reorganized material and reversibility in the case of isotactic polypropylene. A given crystal fraction, characterized by its formation temperature and zero‐entropy‐production melting temperature, has a specific reversibility of the melt‐to‐crystal transition, which is represented by the ratio of the reversible latent heat to the total enthalpy change when the crystal fraction of interest ultimately melts. This specific reversibility is, for ethylene‐1‐octene copolymers, at least 25% at temperatures in the primary crystallization range, and this indicates that the reversible contribution to the total of the melting processes is much larger than expected from simple calculations by the excess apparent reversible heat capacity being referred to the heat of fusion of the polymer, as is commonly done. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2039–2051, 2003     

热分析法研究超高分子量聚乙烯的热熔性质

本文采用差热分析(DTA)、差示扫描量热法(DSC)研究了一系列以高效催化聚合而得的初生态超高分子量(M_w=70-315×10⁴)聚乙烯粉的热熔行为,还研究了在接近熔化或部分熔化的温度下恒温热处理对晶体性质的影响.