用低频拉曼光谱测定树脂固化动力学的方法
Robert V Chimenti1,2, Alexandra M Lehman-Chong2,3, Alyssa M Sepcic4
1Department of Physics & Astronomy, Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA. chimenti@rowan.edu.
The Analyst
|October 12, 2023
概括
本研究介绍了一种拉曼光谱法,用于追踪聚合物网络的形成. 它揭示了甲基酸盐网络的同时结构和化学变化,但在环氧胺网络中反应延迟.
科学领域:
- 聚合物科学与工程 聚合物科学与工程
- 材料化学 材料化学
- 频谱学是一种光谱学.
背景情况:
- 了解聚合物固化动力学对于预测材料特性和加工行为至关重要.
- 拉曼光谱的低频扰乱波段与无形聚合物中的 conformational 和模量相关.
- 这一带在聚合过程中发生显著的变化,为监测治愈提供了潜在的途径.
研究的目的:
- 开发和验证一种基于拉曼光谱的方法,用于描述树脂固化动力学.
- 为了将结构变化 (障碍带) 与聚合过程中的化学转化相关联.
- 研究甲基酸盐,环氧胺和相互透的聚合物网络系统中的治愈行为.
主要方法:
- 使用拉曼光谱分析低频障碍波段及其肩部 (∼85厘米-1).
- 规范了障碍带来量化结构转换动力学.
- 使用现象学速率方程,与化学转换动力学相关的结构转换动力学.
主要成果:
- 建立了正常化的拉曼光谱特征 (结构动力学) 和甲基酸盐和环氧胺系统的化学转换之间的直接相关性.
- 证明了与材料软度相关的化学和结构动力学之间的关系.
- 在初级甲基酸盐网络形成过程中观察到同时发生的结构和化学转化.
- 在相互透的聚合物网络中,在二次环氧氨基胺网络形成期间,在结构和化学转换之间确定了动态滞后.
结论:
- 正常化的拉曼乱带提供了一种强大的方法,用于跟踪聚合物网络形成期间的结构转换动力学.
- 这种光谱方法为各种树脂系统的结构和化学变化之间的相互作用提供了宝贵的见解.
- 这些发现突出了相互透的聚合物网络中的顺序网络形成的独特动态行为.
更多相关视频
07:37An Integrated Raman Spectroscopy and Mass Spectrometry Platform to Study Single-Cell Drug Uptake, Metabolism, and Effects
Published on: January 9, 2020
9.5K
07:29Author Spotlight: Advanced Techniques for Characterizing Tissue Mineralization in Bone Regeneration Research
Published on: September 27, 2024
775
相关概念视频
01:20Raman Spectroscopy: Overview
436
The underlying principle of Raman spectroscopy is based on the interaction between light and matter, specifically molecules' inelastic scattering of photons. When a monochromatic beam of light, typically from a laser source, interacts with a sample, most scattered light has the same frequency as the incident light. This is known as Rayleigh scattering.
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and...
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and...
436
01:26Raman Spectroscopy Instrumentation: Overview
437
A conventional Raman spectrophotometer includes a laser source, a sample holding system, a wavelength selector, and a detector.
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...
437
01:16IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
1.4K
A covalently bonded heteronuclear diatomic molecule can be modeled as two vibrating masses connected by a spring. The vibrational frequency of the bond can be expressed using an equation derived from Hooke's law, which describes how the force applied to stretch or compress a spring is proportional to the displacement of the spring. In this case, the atoms behave like masses, and the bond acts like a spring.
According to Hooke's law, the vibrational frequency is directly proportional to...
According to Hooke's law, the vibrational frequency is directly proportional to...
1.4K
03:09Measuring Reaction Rates
25.3K
Polarimetry finds application in chemical kinetics to measure the concentration and reaction kinetics of optically active substances during a chemical reaction. Optically active substances have the capability of rotating the plane of polarization of linearly polarized light passing through them—a feature called optical rotation. Optical activity is attributed to the molecular structure of substances. Normal monochromatic light is unpolarized and possesses oscillations of the electrical...
25.3K