Related Experiment Video
Updated: Feb 14, 2026

The Frequency Domain Thermoreflectance Technique for Thermal Property Measurements
Published on: December 5, 2025
Effects of Molecular Length and Polarity of Chain Extenders on Microphase Separation and on Thermal and Mechanical
Yaonan Liu1, Renchun Tian1, Xinling Hao1
1Key Laboratory of Rubber-Plastics, Shandong Provincial Key Laboratory of Rubber-Plastics, Ministry of Education, School of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
Abstract:
In this work, rigid polyurethane materials were synthesized via a one-step polymerization method using isocyanate (MDI) and polyether polyol (4110S) as the main raw materials, with 1, 4-butanediol (BDO), 1, 6-hexanediol (HDO), diethylene glycol (DEG), and dipropylene glycol (DPG) as chain extenders. The influence of chain extender structure on the mechanical properties of rigid polyurethane was systematically investigated. The results indicate that when BDO was employed as a chain extender, the polyurethane exhibited the most uniform pore size distribution and the best mechanical properties. It was found that hydrogen bonding plays a dual role: on the one hand, it promotes microphase separation between soft and hard segments; on the other hand, it extends the molecular chains' length, which hinders segment separation and consequently constrains its mechanical properties. Further analysis reveals that the influence of molecular chain length on mechanical properties outweighs that of polarity.
Related Concept Videos
Molecular Shape and Polarity
Molecular and Ionic Solids
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Radical Chain-Growth Polymerization: Mechanism
Anionic Chain-Growth Polymerization: Mechanism
Cationic Chain-Growth Polymerization: Mechanism
Kinetic Molecular Theory and Gas Laws Explain Properties of Gas Molecules

