1. The Scissors Effect in Action: The Fox-Flory Relationship between the Glass Transition Temperature of Crosslinked Poly(Methyl Methacrylate) and Mc in Nanophase Separated Poly(Methyl Methacrylate)-l-Polyisobutylene Conetworks
- Author
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Rolf Prof. Dr. Mühlhaupt, Szabolcs Pásztor, Ralf Thomann, Yi Thomann, Bálint Becsei, Györgyi Szarka, and Béla Iván
- Subjects
Morphology (linguistics) ,Materials science ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,lcsh:Technology ,DSC ,polyisobutylene ,chemistry.chemical_compound ,General Materials Science ,glass transition temperature ,Fox–Flory equation ,Methyl methacrylate ,lcsh:Microscopy ,lcsh:QC120-168.85 ,chemistry.chemical_classification ,scissors effect ,bicontinuous nanophase separation ,lcsh:QH201-278.5 ,Atomic force microscopy ,lcsh:T ,Polymer ,021001 nanoscience & nanotechnology ,poly(methyl methacrylate) ,Poly(methyl methacrylate) ,0104 chemical sciences ,polymer conetworks ,chemistry ,Chemical engineering ,lcsh:TA1-2040 ,visual_art ,visual_art.visual_art_medium ,Molar mass distribution ,lcsh:Descriptive and experimental mechanics ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,AFM ,0210 nano-technology ,Glass transition ,lcsh:Engineering (General). Civil engineering (General) ,lcsh:TK1-9971 - Abstract
The glass transition temperature (Tg) is one of the most important properties of polymeric materials. In order to reveal whether the scissors effect, i.e., the Fox&ndash, Flory relationship between Tg and the average molecular weight between crosslinking points (Mc), reported only in one case for polymer conetworks so far, is more generally effective or valid only for a single case, a series of poly(methyl methacrylate)-l-polyisobutylene (PMMA-l-PIB) conetworks was prepared and investigated. Two Tgs were found for the conetworks by DSC. Fox&ndash, Flory type dependence between Tg and Mc of the PMMA component (Tg = Tg,&infin, &minus, K/Mc) was observed. The K constants for the PMMA homopolymer and for the PMMA in the conetworks were the same in the margin of error. AFM images indicated disordered bicontinuous, mutually nanoconfined morphology with average domain sizes of 5&ndash, 20 nm, but the correlation between Tg and domain sizes was not found. These new results indicate that the macrocrosslinkers act like molecular scissors (scissors effect), and the Tg of PMMA depend exclusively on the Mc in the conetworks. Consequently, these findings mean that the scissors effect is presumably a general phenomenon in nanophase-separated polymer conetworks, and this finding could be utilized in designing, processing, and applications of these novel materials.
- Published
- 2020
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