In Situ Fourier Transform Infrared Spectroscopic Imaging for Elucidating Variations in Chemical Structures of Polymer Composites at the Matrix–Filler Interface during Reactive Processing
journal contributionposted on 02.12.2020, 21:30 by Ryota Watanabe, Aki Sugahara, Hideaki Hagihara, Junji Mizukado, Hideyuki Shinzawa
We have developed a novel in situ Fourier transform infrared (FTIR) spectroscopic imaging technique that can probe the changes in the chemical structures around the matrix–filler interface of polymer composites during reactive processing. We have applied this imaging technique to maleic anhydride grafted styrene-ethylene butylene-styrene triblock copolymer (MA-SEBS) melt-mixed with silica spheres modified with aminopropyl groups (AmSS). In situ FTIR spectroscopic imaging during the heating process indicates that the CO component, attributed to the maleamic acid group, is generated by a reaction between maleic acid and amino groups at temperatures exceeding 175 °C around the matrix–filler interface. It thus appears that the formation of interfacial covalent bonds between matrix and filler contributes to mobility restriction in MA-SEBS molecules around the interface, resulting in the improved tensile strength observed in MA-SEBS/AmSS. In-situ FTIR spectroscopic imaging of this type can provide a better understanding of the reinforcement mechanism of composites by reactive processing.