聚乙烯玻璃体的组合-结构-属性关系,由8臂多面体寡合体silsesquioxane交联
Mikaela Sadri1, Andrew Barbour1, Travis L Thornell2
1School of Polymer Science and Engineering, The University of Southern Mississippi, Hattiesburg, MS, 39406, USA. zhe.qiang@usm.edu.
Soft matter
|March 19, 2025
概括
使用8臂POSS纳米颗粒转化为玻璃基的多聚烯显示强度降低. 这项研究揭示了纳米粒子交联如何影响聚乙烯基玻璃材料的晶度和机械性能.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物化学 聚合物化学
背景情况:
- 与聚乙烯 (PE) 一样,聚烯 (PO) 是具有可取性质的具有成本效益的材料.
- 通过动态交叉连接将POs转化为玻璃剂提供了增强的性能,但由于晶度和相位分离而变得复杂.
- 了解这些影响对于优化基于PO的玻璃化物性能至关重要.
研究的目的:
- 研究聚乙烯衍生玻璃材料的结晶性,交联密度和热力学性能之间的相互作用.
- 分析交叉连接和非交叉连接阶段对整体材料行为的独特贡献.
- 为了评估8臂多面体寡合性丝素 (POSS) 纳米粒子交叉链接剂对半晶性PO-玻璃体的影响.
主要方法:
- 聚乙烯衍生玻璃剂的合成使用反应性8臂POSS纳米颗粒.
- 在玻璃体网络中,交叉连接和非交叉连接组件的解卷.
- 热力学性质的表征,包括模量,抗拉强度,性和破裂时的延长.
- 与双功能交叉连接器模拟器进行比较,以评估交叉连接密度和凝分数效应.
主要成果:
- 不溶性,交联相表现出较低的模量和较高的脆性,与非交联相相比,它表现得像整洁的PE.
- 与8臂POSS交叉连接的聚乙烯-玻璃模具有较低的性和破裂时的延长,同时最终抗拉强度略有增加.
- 观察到的机械行为与交叉连接密度和凝分数的变化一致,无论交叉连接器类型 (多臂纳米粒子与双功能).
结论:
- 多臂,基于纳米粒子的交叉连接器含量显著影响半晶体聚烯玻璃材料的机械性能.
- 网络密度和结晶度的程度是决定这些先进聚合物材料性能的关键因素.
- 这项研究通过控制交叉连接策略,为特定应用设计和优化聚烯玻璃制剂提供了关键的见解.
相关概念视频
01:14Polymer Classification: Architecture
2.6K
Polymers are classified as linear or branched on the basis of their chain architecture. The polymer chains in linear polymers have a long chain-like structure with minimal to no branching at all. Even if a polymer features large substituent groups on the monomer, which appear as branches to the skeleton, it is not considered a branched polymer. A branched polymer contains secondary polymer chains that arise from the main polymer chain. The branching occurs when the polymer growth shifts from...
2.6K
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
01:26Polymer Classification: Stereospecificity
2.4K
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...
2.4K
01:16Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
2.5K
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...
2.5K
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
01:00Characteristics and Nomenclature of Homopolymers
2.9K
Polymers that are made up of identical monomer units are called homopolymers. Only one repeating unit is involved in the construction of the homopolymer structure. For example, as depicted in Figure 1, polypropylene is a homopolymer constituted of propylene monomers. Here, the only repeating unit in the polymer chain is propylene.
2.9K