研究数学模型,用数值方法描述聚合物的热分解
Gaziza M Zhumanazarova1, Akmaral Zh Sarsenbekova2, Lyazzat K Abulyaissova2
1Department of Chemical Technology and Ecology, Karaganda Industrial University, Temirtau 101400, Kazakhstan.
Polymers
|May 14, 2025
概括
这项研究使用数值方法和量子化学模型聚合物热分解. 结果显示,聚合物结构决定了热稳定性,这对于开发新的耐热材料至关重要.
科学领域:
- 聚合物科学 聚合物科学
- 材料化学 材料化学
- 计算化学计算化学
背景情况:
- 聚合物的热分解对于废物回收,能量回收和新材料开发至关重要.
- 了解降解动力学对于预测材料性能和设计先进聚合物至关重要.
研究的目的:
- 为了建模聚乙烯糖醇烟酸甲酸共聚合物的热分解动力学.
- 用各种数值方法和量子化学计算来确定激活能量.
- 研究功能组和化学键对聚合物的热稳定性的影响.
主要方法:
- 热重力测量分析 (TGA) 数据.
- 基于矩阵的数值方法,包括QR,SVD和Cholesky分解,用于解决线性代数方程 (SLAE) 系统.
- 使用密度函数理论 (DFT) 的量子化学计算在B3LYP/6-31G (d) 级.
主要成果:
- 激活能量值是使用Cholesky,正常方程,SVD和QR分解来确定的,显示了微小的变化.
- 量子化学计算为分子结构和红外光谱解释提供了洞察力.
- 功能组含量 (乙,) 和化学键类型显著影响分解机制和热参数.
结论:
- 聚合物的结构结构是其热稳定性的主要决定因素.
- 数字近似和量子化学分析的整合为研究聚合物热行为提供了一种新的方法.
- 这种方法可以指导用于农业和环境应用的耐热聚合物的设计.
相关概念视频
01:08Molecular Weight of Step-Growth Polymers
2.1K
Step growth polymerization involves bi or multifunctional monomers. Bifunctional monomers react to form linear step growth polymers, whereas multifunctional monomers react to form non-linear or branched polymers.
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
2.1K
01:10Polymers: Molecular Weight Distribution
3.1K
For any given polymer, the weight average molecular weight (Mw) is higher than, if not equal to, the number average molecular weight (Mn). The only situation in which the weight average molecular weight and the number average molecular weight are equal is when a polymer consists only of chains with equal molecular weight. However, this never happens in a synthetic polymer, since it is difficult to control the polymerization process up to a molecular level with accuracy to a hundred percent.
3.1K
01:01Polymers: Defining Molecular Weight
2.7K
Unlike small molecules with definite molecular weights, polymers are a mixture of individual polymer chains of varying lengths, each with a unique molecular weight. So, the molecular weight of a polymer is expressed as an average value based on the average size of the polymer chains. The two most common forms of averages used for polymers are the number average molecular weight and weight average molecular weight.
The number average molecular weight (Mn) is the summation of the number...
The number average molecular weight (Mn) is the summation of the number...
2.7K
02:34Polymers
33.9K
The word polymer is derived from the Greek words “poly” which means “many” and “mer” which means “parts”. Polymers are long chains of molecules composed of repeating units of smaller molecules, known as monomers. They either occur naturally, such as DNA and proteins, or can be constructed synthetically, like plastics. They have varied structural characteristics, such as linear chains, branched chains, or complex networks, that contribute to the...
33.9K
01:30Typical Model Studies
161
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
161
01:21Polymer Classification: Crystallinity
2.7K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
2.7K