相关实验视频

Updated: Jun 21, 2025

Application of a Coupling Agent to Improve the Dielectric Properties of Polymer-Based Nanocomposites

Application of a Coupling Agent to Improve the Dielectric Properties of Polymer-Based Nanocomposites

Published on: September 19, 2020

提高高密度聚乙烯等级的环境应力破裂阻力,通过共纳米添加和纳米复合材料方法

AmirMohammad Mansouri¹, Nona Ghasemi Hamedani², Chen Zou³

¹Kermanshah Polymer Petrochemical Company, Kermanshah, Iran.

Chemistry (Weinheim an der Bergstrasse, Germany)

|July 17, 2024

概括

这项研究表明,在高密度聚乙烯 (HDPE) 中增加短链分支 (SCB) 提高了其环境应力裂变阻力 (ESCR). 添加纳米二氧化进一步提高了ESCR的40%.

科学领域:

聚合物科学与工程聚合物科学与工程
材料科学材料科学材料科学

背景情况:

高密度聚乙烯 (HDPE) 是一种广泛使用的聚合物.
它的机械性能和对环境应力裂变 (ESCR) 的抗性对于应用至关重要.
众所周知,comonomer含量和纳米酸盐添加剂会影响HDPE的特性.

研究的目的:

为了研究聚合物密度的影响,与comonomer含量相关,并在HDPE上添加nanosilica.
评估HDPE机械性能和ESCR的变化.
了解使用计算方法的comonomers的作用.

主要方法:

采集了五个HDPE样本,密度不同,但融化流量指数 (MFI) 和摩尔质量相似.
使用凝浸透色谱 (GPC) 和连续自我核和化 (SSA) 分析了样本微观结构.
进行了机械测试和环境应力破裂阻力 (ESCR) 测试.
用密度函数理论 (DFT) 进行计算分析.

主要成果:

样本显示每1000个碳的短链分支 (SCB/1000C) 略有变化,从7.26到9.74.
拉伸模量,断裂时应力和断裂时延长因SCB含量而有所不同.
较高的SCB内容显著改善了ESCR.
将HDPE与3重%化学改性纳米二氧化增强ESCR40%的高SCB混合.

结论:

短链分支 (SCB) 含量是影响HDPE机械性能和ESCR的关键因素.
增加SCB内容导致ESCR增强.
纳米二氧化的添加进一步提高了ESCR,为材料改进提供了一个有前途的途径.
DFT计算提供了关于comonomer在分子水平上的作用的见解.

关键词:

环境应力裂解电阻 (ESCR) 是一种高密度聚乙烯的高密度聚乙烯拉梅拉的厚度拉梅拉的厚度短链分支机构短链分支机构齐格勒-纳塔催化剂是一种催化剂.

更多相关视频

Advanced Compositional Analysis of Nanoparticle-polymer Composites Using Direct Fluorescence Imaging

Advanced Compositional Analysis of Nanoparticle-polymer Composites Using Direct Fluorescence Imaging

Published on: July 19, 2016

The Effect of Construction and Demolition Waste Plastic Fractions on Wood-Polymer Composite Properties

The Effect of Construction and Demolition Waste Plastic Fractions on Wood-Polymer Composite Properties

Published on: June 7, 2020

相关概念视频

Polymer Classification: Architecture

Polymer Classification: Architecture

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...

Types of Step-Growth Polymers: Polyesters

Types of Step-Growth Polymers: Polyesters

The introduction of polyesters has brought major development to the textile industry. The wrinkle-free behavior of polyester blends has eliminated the need for starching and ironing clothes.
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the...

Free-Radical Chain Reaction and Polymerization of Alkenes

Free-Radical Chain Reaction and Polymerization of Alkenes

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.

Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)

Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)

Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...

Olefin Metathesis Polymerization: Overview

Olefin Metathesis Polymerization: Overview

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...

Polymer Classification: Stereospecificity

Polymer Classification: Stereospecificity

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...