Thermochimica Acta最新文献

英文中文

Investigation of pyrolysis and combustion characteristics of chili straw waste with different O2/N2 ratios and heating rates 不同 O2/N2 比率和加热速率下辣椒秸秆废物热解和燃烧特性的研究

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-10-10 DOI: 10.1016/j.tca.2024.179875

Pengyu Wei , Guoyan Chen , Fubiao Zhi , Anchao Zhang , Haoxin Deng , Xiaoping Wen , Fahui Wang , Chenglong Yu

To utilize chili straw waste (CSW) for energy production and generate higher-quality fuel, the pyrolysis characteristics of CSW under varying particle sizes and heating rates, as well as the effects of different O₂/N₂ ratios on its combustion characteristics, were investigated using Thermogravimetry-Mass Spectrometry (TG-MS). The gas production performance under three different conditions was also analyzed. Results indicated that the solid yield decreased as particle size increased, with the maximum weight loss rate of 77.79 % occurring at a particle size of 1.25∼1.60 mm. The highest relative pyrolysis rate was 0.77 %/K at a heating rate of 10 K/min, corresponding to a weight loss rate of 74.46 %. Increasing the proportion of oxygen in the atmosphere reduced both the ignition and burnout temperatures of CSW by 9.34 K and 51.89 K, respectively, shifting the Derivative Thermogravimetry (DTG) curve to a lower temperature range. Furthermore, an increase in the heating rate enhanced hydrogen production intensity during CSW pyrolysis, with the peak particle current of H₂ rising from 8.7 × 10⁻¹⁰ A to 1.2 × 10⁻⁹ A, representing a 0.38-fold increase when the heating rate was raised from 5 K/min to 40 K/min. A kinetic analysis of CSW pyrolysis using the Coats-Redfern (CR) and Achar methods revealed that activation energy (E_a) increases with particle size, indicating higher energy requirements due to heat transfer resistance. The Friedman, Kissinger-Akahira-Sunose (KAS), and Ozawa-Flynn-Wall (OFW) methods showed rising E_a with increasing conversion rates, corresponding to the decomposition of hemicellulose, cellulose, and lignin. In combustion, oxygen concentration significantly influences E_a, raising it for volatile matter and fixed carbon, and also increasing it for lignin at high temperatures. The CR and Achar models provided strong fits, confirming their reliability in describing CSW pyrolysis and combustion.

为了利用辣椒秸秆废弃物（CSW）生产能源并生成更高质量的燃料，我们使用热重分析-质谱法（TG-MS）研究了不同颗粒大小和加热速率下 CSW 的热解特性，以及不同 O2/N2 比率对其燃烧特性的影响。此外，还分析了三种不同条件下的产气性能。结果表明，固体产量随着粒径的增大而减少，粒径为 1.25 ∼ 1.60 毫米时的失重率最大，为 77.79%。加热速度为 10 K/min 时，相对热解率最高，为 0.77 %/K，相应的重量损失率为 74.46 %。大气中氧气比例的增加使 CSW 的点火温度和燃尽温度分别降低了 9.34 K 和 51.89 K，从而使衍生热重（DTG）曲线向更低的温度范围移动。此外，当加热速率从 5 K/min 提高到 40 K/min 时，H2 的峰值粒子电流从 8.7 × 10-10 A 上升到 1.2 × 10-9 A，增加了 0.38 倍。使用 Coats-Redfern (CR) 和 Achar 方法对 CSW 高温分解进行的动力学分析表明，活化能（Ea）随颗粒大小的增加而增加，这表明由于热传导阻力的存在，需要更高的能量。Friedman、Kissinger-Akahira-Sunose（KAS）和 Ozawa-Flynn-Wall （OFW）方法显示，随着转化率的增加，Ea 也在增加，这与半纤维素、纤维素和木质素的分解相对应。在燃烧过程中，氧气浓度对 Ea 有很大影响，挥发物和固定碳的 Ea 会升高，木质素在高温下的 Ea 也会升高。CR 模型和 Achar 模型的拟合度很高，证实了它们在描述 CSW 热解和燃烧方面的可靠性。

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引用次数: 0

Kinetic model of thermal decomposition of nitric acid solutions of hydrazine nitrate 硝酸溶液热分解硝酸肼的动力学模型

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-10-09 DOI: 10.1016/j.tca.2024.179876

Vera Kalistratova, Arseniy Obedkov, Elena Belova

The kinetic parameters of thermal decomposition of an aqueous solution containing 0.029 mass fractions of hydrazine nitrate and 0.44 mass fractions of nitric acid have been determined: onset temperature and specific thermal effect of exothermic reactions, activation energy, pre-exponential factor, reaction rate and order. Based on the data obtained, a mathematical model of thermal decomposition of nitric acid solutions of hydrazine nitrate has been proposed. It has been found that thermolysis of the solution has a multi-stage nature and can be described by a system of 5 equations of 1st and 2nd order. A comparison of two approaches to creating a mathematical model has been carried out: based on adiabatic calorimetry and differential scanning calorimetry data.

确定了含有 0.029 质量分数硝酸肼和 0.44 质量分数硝酸的水溶液热分解的动力学参数：放热反应的起始温度和比热效应、活化能、前指数因子、反应速率和顺序。根据所获得的数据，提出了硝酸肼硝酸溶液热分解的数学模型。研究发现，溶液的热分解具有多级性质，可以用 5 个一阶和二阶方程系统来描述。对建立数学模型的两种方法进行了比较：基于绝热量热法和差示扫描量热法数据。

引用次数: 0

Sublimation rate of solid NaCl powders and evaporation rate of liquid NaCl upon heating in vacuum and air 固体氯化钠粉末在真空和空气中加热时的升华速率和液体氯化钠的蒸发速率

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-10-06 DOI: 10.1016/j.tca.2024.179874

Alexander M. Laptev , Martin Bram

The volatilization of sodium chloride (NaCl) is important for multiple applications, such as energy storage, manufacturing porous parts, and purification and recycling of composites. Until now, only limited information on this feature has been published. To expand the knowledge in this field, we investigated the sublimation and evaporation of two NaCl powders by thermal gravimetry in vacuum and air. The study has shown that the volatilization kinetics of powders with different shapes and sizes are identical. The volatilization of NaCl powders in vacuum occurs mainly by sublimation before melting. In contrast, the volatilization of NaCl in the air is preferentially caused by the evaporation of the melt. In a vacuum, the evaporation of NaCl powder after melting is significantly slower than the sublimation before melting, because of a drastic decrease in the volatilization area. The Hertz-Knudsen relation with an appropriate fitting coefficient satisfactorily describes the mass loss by volatilization in vacuum and air.

氯化钠（NaCl）的挥发对多种应用都很重要，如能量储存、多孔部件制造、复合材料的净化和回收。到目前为止，有关这一特性的信息还很有限。为了扩展这一领域的知识，我们通过热重力仪研究了两种氯化钠粉末在真空和空气中的升华和蒸发。研究表明，不同形状和大小的粉末的挥发动力学是相同的。氯化钠粉末在真空中的挥发主要是在熔化前升华。相反，NaCl 在空气中的挥发主要是由熔体的蒸发引起的。在真空中，NaCl 粉末熔化后的蒸发速度明显慢于熔化前的升华速度，这是因为挥发面积急剧下降。具有适当拟合系数的赫兹-克努森（Hertz-Knudsen）关系式可以令人满意地描述真空和空气中挥发的质量损失。

引用次数: 0

Experimental determination of phase stability of the cubic L12 HfAl3-xZnx phase 立方 L12 HfAl3-xZnx 相的相稳定性实验测定

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-10-02 DOI: 10.1016/j.tca.2024.179873

S. Delsante , G. Borzone , N. Parodi , S. Guerrucci

The present study is devoted to the experimental investigation of homogeneity range and heat of formation (Δ_fH° at 300 K) of the cubic L1₂–HfAl_3-xZn_x solid solution. A high-temperature direct drop calorimeter has been employed to synthesize and simultaneously determine the Δ_fH° of several alloys along the HfZn₃–HfAl₃ section (25 at. % Hf) whereas X-Ray Powder Diffraction (XRPD) and Scanning Electron Microscopy (SEM) paired with an EDS (Energy Dispersive Spectrometer detector) have been employed to characterize the samples. The performed analysis confirmed that the ternary HfAl_3-xZn_x alloys were nearly single phase in the range 1 ≤ x ≤ 2.24 having the cubic L1₂ structure; this in turn helps establish the trend of L1₂ lattice parameter (at room temperature) with composition. Thanks to the interpolation of our experimental data, the following values of Δ_fH° (kJ/mol-atom at 300 K) for the L1₂–HfAl_3-xZn_x were determined: -37.1 ± 2.0 (HfAl_0.8Zn_2.2 corresponding to Hf₂₅Al₂₀Zn₅₅ at. %), -41.7 ± 2.0 (HfAl_1.2Zn_1.8 corresponding to Hf₂₅Al_30.0Zn_45.0 at. %), -45.1 ± 2.0 (HfAl_1.5Zn_1.5 corresponding to Hf₂₅Al_37.5Zn_37.5 at. %) and -48.5 ± 2.0 (HfAl_1.8Zn_1.2 corresponding to Hf₂₅Al_45.0Zn_30.0 at. %). For two pertinent binary intermetallic phases, the following Δ_fH° values (in kJ/mol-atom) at 300 K have been obtained: -31.8 ± 3.0 for HfZn₃ (unknown structure) and -37.0 ± 2.0 for HfAl₃ (tetragonal DO₂₃ – type structure).

本研究致力于对立方体 L12-HfAl3-xZnx 固溶体的均匀性范围和形成热（ΔfH°，300 K）进行实验研究。我们使用高温直接滴热量计合成并同时测定了 HfZn3-HfAl3 部分（25% Hf）几种合金的 ΔfH°，同时使用 X 射线粉末衍射 (XRPD) 和扫描电子显微镜 (SEM) 搭配 EDS（能量色散光谱仪检测器）对样品进行表征。所进行的分析证实，三元 HfAl3-xZnx 合金在 1 ≤ x ≤ 2.24 的范围内几乎是单相的，具有立方 L12 结构；这反过来又有助于确定 L12 晶格参数（室温下）随成分变化的趋势。通过对我们的实验数据进行插值，确定了 L12-HfAl3-xZnx 的 ΔfH° 值（300 K 时为 kJ/mol-原子）：-37.1 ± 2.0（HfAl0.8Zn2.2 对应 Hf25Al20Zn55 at.%）、-41.7 ± 2.0（HfAl1.2Zn1.8，相当于 Hf25Al30.0Zn45.0 at.%）、-45.1 ± 2.0（HfAl1.5Zn1.5，相当于 Hf25Al37.5Zn37.5 at.%）和 -48.5 ± 2.0（HfAl1.8Zn1.2，相当于 Hf25Al45.0Zn30.0 at.%）。对于两种相关的二元金属间相，在 300 K 时获得了以下 ΔfH° 值（单位：kJ/mol-atom）：HfZn3（未知结构）为 -31.8 ± 3.0，HfAl3（四方 DO23 型结构）为 -37.0 ± 2.0。

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引用次数: 0

Kinetics of L-lactide bulk polymerization initiated with zirconium(IV) acetylacetonate studied by non-isothermal differential scanning calorimetry 通过非等温差示扫描量热法研究乙酰丙酮锆（IV）引发的 L-内酰胺大体积聚合动力学

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-10-01 DOI: 10.1016/j.tca.2024.179872

Kirill T. Kalinin , Dmitry R. Streltsov , Petr V. Dmitryakov , Nikita G. Sedush , Sergei N. Chvalun

The kinetics of L-lactide bulk polymerization initiated with a non-toxic initiator, zirconium(IV) acetylacetonate, was studied by non-isothermal differential scanning calorimetry. The polymerization kinetics was analyzed using a combination of isoconversional “model–free” and model–fitting methods. It was revealed that the model–free analysis results in an autocatalytic reaction model function. To provide a physical meaning for this effective reaction model, a model–fitting analysis with a two–step kinetic model taking into account irreversible initiation and reversible propagation reactions was applied. It was demonstrated, that even such simple multi–step kinetic model can explain the general features of the polymerization reaction revealed by the isoconversional analysis, i.e. a variation of the effective activation energy with a conversion degree and an autocatalytic character of the effective reaction model. The rate constants for the initiation,

k_{i}

, and propagation,

k_{p}

, reactions were evaluated. It was revealed that the values of

k_{i}

are about two decimal orders lower than that of

k_{p}

indicating slow initiation in the studied temperature range.

采用非等温差示扫描量热法研究了无毒引发剂乙酰丙酮锆（IV）引发的 L-内酯批量聚合的动力学。聚合动力学分析采用了等转换 "无模型 "法和模型拟合法相结合的方法。结果表明，无模型分析得出了一个自催化反应模型函数。为了给这一有效的反应模型提供物理意义，采用了考虑到不可逆启动和可逆传播反应的两步动力学模型进行模型拟合分析。结果表明，即使是这种简单的多步动力学模型也能解释等转化分析所揭示的聚合反应的一般特征，即有效活化能随转化率的变化和有效反应模型的自催化特性。对引发反应的速率常数 ki 和传播反应的速率常数 kp 进行了评估。结果表明，ki 的值比 kp 的值低约小数点后两位，这表明在所研究的温度范围内，起始速度较慢。

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引用次数: 0

Kinetics and mechanism of thermal and thermo-oxidative degradation for high-density polyethylene modified by fullerene and its derivative 富勒烯及其衍生物改性高密度聚乙烯的热降解和热氧化降解动力学与机理

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-09-24 DOI: 10.1016/j.tca.2024.179871

Bingtao Wang , Yanqun Pan , Liping Zhao , Juan Li , Zhenghong Guo

To investigate the effect of fullerene (C₆₀) and its iron compound (C₆₀-Fe) on the thermal and thermo-oxidative degradation mechanism of high-density polyethylene (HDPE), the Kissinger method, Flynn-Wall-Ozawa method and Coats-Redfern methods are used. The data of thermal and thermo-oxidative degradation are achieved through the thermogravimetric (TG) analysis, and the trapping free-radical ability and the dispersion of C₆₀ or C₆₀-Fe in matrix are characterized by the electron spin resonance (ESR) and transmission electron microscopy (TEM). C₆₀ and C₆₀-Fe improve effectively the thermal and thermo-oxidative stability of HDPE. In N₂, C₆₀ and C₆₀-Fe do not change the degradation mechanism of HDPE, and the degradation rate is determined by the random generation and growth of free-radicals. In air, C₆₀ changes the reaction order (n) of HDPE at the oxidation stage and the degradation mechanism at the random fracture. C₆₀-Fe changes the thermo-oxidative mechanism of HDPE due to the formation of cross-linked network.

为了研究富勒烯（C60）及其铁化合物（C60-Fe）对高密度聚乙烯（HDPE）热降解和热氧化降解机理的影响，采用了基辛格法、Flynn-Wall-Ozawa 法和 Coats-Redfern 法。热重（TG）分析获得了热降解和热氧化降解的数据，电子自旋共振（ESR）和透射电子显微镜（TEM）表征了 C60 或 C60-Fe 在基体中捕获自由基的能力和分散性。C60 和 C60-Fe 能有效提高高密度聚乙烯的热稳定性和热氧化稳定性。在氮气中，C60 和 C60-Fe 不会改变高密度聚乙烯的降解机理，降解速率由自由基的随机生成和增长决定。在空气中，C60 改变了高密度聚乙烯氧化阶段的反应顺序（n）和随机断裂的降解机理。由于形成了交联网络，C60-Fe 改变了高密度聚乙烯的热氧化机理。

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引用次数: 0

Pyrolysis kinetics and flame retardant enhancement of bio-based polyamide 56/6 生物基聚酰胺 56/6 的热解动力学和阻燃性能的提高

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-09-21 DOI: 10.1016/j.tca.2024.179869

Xiaoqi Zhang , Haoyu Yang , Yaxin Guo , Jie Zhou , Hao Liu , Suqin He , Miaoming Huang , Wanlin Xu , Chengshen Zhu , Wentao Liu

The development of polyamide materials with fire safety is of great importance at this stage. A novel nitrogen-phosphorus bisystem flame retardant (MC) with a multi-branched structure was synthesized and applied to a new bio-based polyamide 56/6 (PA56/6). Notably, at 8 wt% MC content, flame-retardant PA56/6@MC_8% (FRPA56/6@MC_8%) achieved an Limiting Oxygen Index (LOI) of 26.6% and a V-0 rating in UL-94 tests. Cone calorimetry results indicated that FRPA56/6@MC_8% exhibited a 22.9% reduction in total heat release (THR) and a 41.0% decrease in peak heat release rate (PHRR), underscoring the flame retardancy promotion by MC in PA56/6. The study further explored the pyrolysis kinetics and mechanisms of polyamide materials, offering insights crucial for flame-retardant modifications. Overall, the findings present an innovative strategy for enhancing the flame retardant properties of PA56/6, potentially applicable in automotive components and other pertinent fields.

现阶段，开发具有防火安全性的聚酰胺材料具有重要意义。研究人员合成了一种具有多分支结构的新型氮磷双体系阻燃剂（MC），并将其应用于新型生物基聚酰胺 56/6（PA56/6）。值得注意的是，在 MC 含量为 8 wt% 时，阻燃 PA56/6@MC8% （FRPA56/6@MC8%）的极限氧指数（LOI）达到 26.6%，在 UL-94 测试中达到 V-0 级。锥形量热仪结果表明，FRPA56/6@MC8% 的总放热量 (THR) 降低了 22.9%，峰值放热率 (PHRR) 降低了 41.0%，突出表明了 MC 在 PA56/6 中的阻燃性能。该研究进一步探讨了聚酰胺材料的热解动力学和机理，为阻燃改性提供了至关重要的见解。总之，研究结果提出了一种增强 PA56/6 阻燃性能的创新策略，可用于汽车部件和其他相关领域。

引用次数: 0

Flammability of Novolac epoxy cured with aromatic diamines 用芳香族二胺固化的 Novolac 环氧树脂的可燃性

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-09-19 DOI: 10.1016/j.tca.2024.179870

Mauro R.S. Silveira , Vicente F. Moritz , Carlos A. Ferreira , Laurent Ferry , José-Marie Lopez-Cuesta

The modification of Novolac epoxy with the organophosphorus compound 9,10-dihydro-9-oxa-10-phosphaphenanthren-10-oxide (DOPO) to reduce flammability and its influence on curing reactions has been investigated. Three aromatic diamine curing agents were used, namely 4,4′-diaminodiphenylmethane (DDM), 4,4′-diaminodiphenylsulphone (DDS), and diethyltoluenediamine (DETDA). The thermal stability and dynamic-mechanical behaviour of the cured resin depend on interactions of the curing agent with DOPO. The onset degradation temperature decreased with increasing phosphorus content, indicating the influence of DOPO on thermal stability. The DDM 3 %P sample exhibited the highest glass transition (Tg) of 136 °C, while DDS-crosslinked simples displayed the highest Tg of 147 °C among all samples. An improvement in the reaction of Novolac epoxy to fire was achieved by incorporating DOPO compound, as indicated by cone calorimetry results, showing up to a 67 % reduction in the peak heat release rate (pHRR) and 53 % reduction in total heat release (THR) for DDM 3 %P. The modified samples containing DOPO presented a self-extinguishing performance, displaying a UL-94 V-0 rating and a limiting oxygen index (LOI) values reached a maximum of 37.1 % for DDM 3 %P, with less flame propagation than for neat Novolac epoxy.

研究了用有机磷化合物 9,10-二氢-9-氧杂-10-磷菲-10-氧化物（DOPO）对 Novolac 环氧树脂进行改性以降低易燃性及其对固化反应的影响。使用了三种芳香族二胺固化剂，即 4,4′-二氨基二苯甲烷（DDM）、4,4′-二氨基二苯砜（DDS）和二乙基甲苯二胺（DETDA）。固化树脂的热稳定性和动态机械性能取决于固化剂与 DOPO 的相互作用。起始降解温度随着磷含量的增加而降低，这表明 DOPO 对热稳定性有影响。DDM 3 %P 样品的玻璃化转变温度（Tg）最高，为 136 °C，而在所有样品中，DDS 交联模拟物的玻璃化转变温度（Tg）最高，为 147 °C。锥形量热仪结果表明，加入 DOPO 化合物后，Novolac 环氧树脂的着火反应有所改善，DDM 3 %P 的峰值放热率（pHRR）降低了 67%，总放热率（THR）降低了 53%。含有 DOPO 的改性样品具有自熄灭性能，达到了 UL-94 V-0 等级，DDM 3 %P 的极限氧指数（LOI）值最高达到 37.1%，与纯净的 Novolac 环氧树脂相比，火焰蔓延更小。

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引用次数: 0

Organic compounds as temperature calibrants for fast scanning calorimetry 用作快速扫描量热仪温度校准器的有机化合物

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-09-14 DOI: 10.1016/j.tca.2024.179868

Timur A. Mukhametzyanov , Airat A. Notfullin , Alisa A. Fatkhutdinova , Christoph Schick

Organic compounds can be used as temperature calibrants in fast scanning calorimetry. Their advantages include ease of surface cleaning of the calorimetric chip and good thermal contact with the chip surface. Among several compounds tested, benzoic acid was identified as a convenient and reliable calibrant for temperatures below approximately 130 °C. However, organic calibrants often exhibit unusual heating rate dependencies of the onset temperatures of melting. This phenomenon can be semi-quantitatively explained by considering different heat flows within the sensor. Notably, the thermal resistance between the heater and thermopile, often overlooked, introduces an additional time constant that can sometimes result in a negative apparent thermal lag. In addition, the onset temperatures are influenced by factors such as sample position, thickness, surface wetting, and spreading. These factors limit the accuracy of transition temperature determinations to approximately ±1 K below 130 °C and ±5 K up to 220 °C.

有机化合物可用作快速扫描量热仪的温度校准器。有机化合物的优点包括易于清洁量热芯片的表面以及与芯片表面良好的热接触。在测试的几种化合物中，苯甲酸被认为是温度低于约 130 °C 时方便可靠的校准物。然而，有机定标物在开始熔化的温度上往往表现出不寻常的加热速率依赖性。考虑到传感器内的不同热流，这种现象可以得到半定量的解释。值得注意的是，加热器和热电堆之间的热阻经常被忽视，它会带来一个额外的时间常数，有时会导致负的表观热滞后。此外，起始温度还受到样品位置、厚度、表面润湿和扩散等因素的影响。这些因素将过渡温度测定的精确度限制在 130 °C 以下约 ±1 K 和 220 °C 以下 ±5 K。

引用次数: 0

Secondary crystallization of low-isotacticity polypropylene 低异构聚丙烯的二次结晶

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-09-14 DOI: 10.1016/j.tca.2024.179867

Yoshitomo Furushima , Akihiko Toda , Kazuo Kimura , Masaru Nakada , Akihiro Masuda , Kazuya Nakamura , Hideaki Takahashi , Toshiumi Tatsuki , Kazuma Okada , Masatoshi Ohkura

This study aimed to clarify the secondary crystallization process of low-isotacticity polypropylene (LT-PP). LT-PP demonstrates an exceptionally low crystallization rate at room temperature, which is approximately 1/5000 lower than that of isotactic PP (iPP). During the secondary crystallization of LT-PP at 30 °C, the thickness of lamellar (c-axis) and a- and b-axes of crystallite size remained constant. In addition, no significant change was observed in the CC-C bending vibration. It seems that the direction of the CC-C molecular order is similar to the thickness direction. This vibration mode may be associated with changes in the thickness of the lamellae. To explain the log(t) dependence of crystallinity, the Seto–Frank model was employed.

本研究旨在阐明低异构聚丙烯（LT-PP）的二次结晶过程。LT-PP 在室温下的结晶速率极低，比同轴聚丙烯（iPP）低约 1/5000。LT-PP 在 30 °C 的二次结晶过程中，片层厚度（c 轴）以及结晶尺寸的 a 轴和 b 轴保持不变。此外，CC-C 弯曲振动也没有发生明显变化。由此看来，CC-C 分子顺序的方向与厚度方向相似。这种振动模式可能与薄片厚度的变化有关。为了解释结晶度的对数（t）依赖性，我们采用了 Seto-Frank 模型。

引用次数: 0

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