New Insights into Segmental Packing, Chain Dynamics and Thermomechanical Performance of Aliphatic Polyurea Composites: Comparison between Silica Oxides and Titanium (III) Oxides. Issue 1 (9th November 2021)

• Record Type: Journal Article
• Authors: Palaniandy, Khanisya; Auckloo, Sheik Ambarine Banon; Cavallaro, Giuseppe; Chan, Eng Seng; Pasbakhsh, Pooria
• Is Part Of: Macromolecular materials and engineering. Volume 307:Issue 1(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-09
• Subjects: polyurea dynamics -- segmental packing -- silica oxide -- solvent‐free polyurea -- titanium (III) oxide; Plastics -- Periodicals; Polymers -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1002/mame.202100582
• Languages: English
• ISSNs: 1438-7492

Abstract

Abstract: Polyurea (PU) is intrinsically reinforced by its microphase‐separated morphology, giving its excellent mechanical properties. In this study, it is shown how a high‐index PU formulation applies easy diffusion of hard segments into the soft phase of the PU matrix and tune its chain mobility. Moreover, the interaction of micro (>100 nm), nano (<100 nm) fillers with the microdomains and their thermomechanical properties are unraveled. Herein, nanosilica oxide (NS) and micro titanium (III) oxide (Ti2 O3 ) are incorporated at low loadings into a solvent‐free two‐component aliphatic PU via insitu polymerization. While NS achieves an interfacial interaction with urea groups and forms a tight hard segmental packing, the large‐sized Ti2 O3 assembles the interconnected PU chain network, improving its crystallinity. Strong reinforcement by NS is noticed when tensile strength increased from 26 to 31 MPa and on the maximum thermal degradation temperature by 21 °C increment from the neat PU. In contrast, the soft segmental dynamics are triggered with the presence of Ti2 O3 as indicated in the reduction in glass transition temperature and the 288% improvement in the storage modulus. This study provides an insightful perspective in designing robust PU composites, effective for myriad applications including strong and flexible films in circuit boards and photovoltaic (PV) cells. Abstract : The addition of silica oxide (SiO2 ) nanofiller and titanium (III) oxide (Ti2 O3 ) micro filler into a high‐index aliphatic polyurea (PU) matrix, respectively, results in an engaging interaction mechanism (see picture) by strongly influencing the segmental packing, chain motion, and orientation, which translate to enhancement in mechanical, thermal, and physical performances of PU.