洞察塑料废物的热解机制,其中脊柱中的C-O/C-N键具有C-O/C-N键
Guanyu Wang1, Zihang Zhang1, Dan Xu1
1State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
The Science of the total environment
|July 7, 2023
概括
这项研究揭示了含有C-O/C-N键的塑料的热解机制. 聚乙烯二甲 (PET) 和尼龙6具有独特的降解途径和热稳定性,为塑料废物利用提供了洞察力.
科学领域:
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
- 聚合物化学 聚合物化学
背景情况:
- 热解对于塑料废物回收至关重要,将其转化为有价值的单体,燃料和化学品.
- 了解具有C-O/C-N键的塑料的热解机制至关重要,但目前缺乏深入和全面的研究.
研究的目的:
- 综合研究具有C-O/C-N键的塑料的宏观和微观热解过程.
- 通过使用键解离能 (BDE) 计算来评估打破不同骨干连接的难度.
- 为了深入揭示这些塑料复杂的热解机制.
主要方法:
- 用C-O/C-N键对塑料进行实验性热解.
- 密度函数理论 (DFT) 计算以确定键解离能 (BDE).
- 对宏观和微观降解行为和产品分布的分析.
主要成果:
- 聚乙烯二甲 (PET) 显示出较高的初始热解温度和比尼龙6稍高的热稳定性.
- 聚乙烯骨干分解主要涉及Cα-O裂变,而尼龙6降解始于终端NH2组.
- 通过PET热解,从CO/CC键裂解中获得小分子碎片;尼龙6主要产生.
结论:
- 聚乙烯热解遵循一种竞争机制,涉及CC和相邻的Cα-O键裂解.
- 尼龙6对卡普罗拉克坦的热解主要通过协同的胺CN键反应发生,骨干CC键裂变不那么显著.
相关概念视频
Free-Radical Chain Reaction and Polymerization of Alkenes
8.0K
The conversion of alkenes to macromolecules called polymers is a reaction of high commercial importance. The structure of the polymer is defined by a repeating unit, while the terminal groups are considered insignificant. The average degree of polymerization represents the number of repeating units in the polymer molecule and is denoted by the subscript n.
8.0K
Radical Chain-Growth Polymerization: Chain Branching
2.0K
The skeletal structure of polymers synthesized via radical polymerization is always branched. For example, the polymerization of ethylene by radical polymerization results in a low-density grade of polyethylene with a heavily branched skeletal structure. Here, the radical site abstracts hydrogen from the growing chain, and the radical site shifts from the end (a primary carbon center) to anywhere within the growing chain (a secondary carbon center). Consequently, the part of the chain from the...
2.0K
Olefin Metathesis Polymerization: Overview
2.2K
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
2.2K
Combustion Energy: A Measure of Stability in Alkanes and Cycloalkanes
6.4K
The low reactivity in alkanes can be attributed to the non-polar nature of C–C and C–H σ bonds. Alkanes, therefore, were initially termed as “paraffins,” derived from the Latin words: parum, meaning “too little,” and affinis, meaning “affinity.”
Alkanes undergo combustion in the presence of excess oxygen and high-temperature conditions to give carbon dioxide and water. A combustion reaction is the energy source in natural gas, liquified...
Alkanes undergo combustion in the presence of excess oxygen and high-temperature conditions to give carbon dioxide and water. A combustion reaction is the energy source in natural gas, liquified...
6.4K
Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
2.6K
Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...
2.6K
Carbon Skeletons
107.8K
Life on Earth is carbon-based, as all macromolecules that make up living organisms contain carbon atoms. All organic compounds have a carbon backbone. Each carbon atom is tetravalent and can bond with four other atoms, making it an extraordinarily flexible component of biological molecules. Because carbon’s valence electrons are stable, it rarely becomes an ion. As the carbon chain increases in length, structural modifications such as ring structures, double bonds, and branching side...
107.8K


