Molecular Weight Dependence of Interdiffusion and Adhesion of Polymers at Short Contact Times
The autohesion and subsequent debonding of thin layers of three linear and monodisperse random copolymers of styrene-butadiene (SBR) with molecular weights varying between 30 and 75 times the average molecular weight between entanglements Me were investigated using a carefully controlled tack adhesi...
Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 33(2017), 7 vom: 21. Feb., Seite 1670-1678 |
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1. Verfasser: | |
Weitere Verfasser: | , , , |
Format: | Online-Aufsatz |
Sprache: | English |
Veröffentlicht: |
2017
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Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
Schlagworte: | Journal Article Research Support, Non-U.S. Gov't |
Zusammenfassung: | The autohesion and subsequent debonding of thin layers of three linear and monodisperse random copolymers of styrene-butadiene (SBR) with molecular weights varying between 30 and 75 times the average molecular weight between entanglements Me were investigated using a carefully controlled tack adhesion testing device in conjunction with a fast camera setup over a range of contact times tc (10 ms to 10 s) much shorter in comparison to the terminal relaxation times of the polymers. The evolution of the stress-strain curves and debonding mechanisms with increasing contact time was examined, and the work required to debond the layers was found to be strongly dependent on molecular weight at long contact times, but not at short contact times. We propose a cutoff contact time of 300 ms, corresponding to 104 times the entanglement time τe after which molecular weight becomes important in controlling the interdiffusion process and the debonding mechanisms of the tack test. For contact times over 300 ms, the debonding energy plotted as a function of tc normalized by the reptation time τrep, collapses onto a master curve. Below this threshold tc, by comparing the adhesion of SBR on itself with the adhesion of SBR on glass, we also show that interdiffusion plays a part in adhesion of two identical polymer layers even at the shortest contact times, where the interdiffusion is controlled by the number of entanglements formed which scales with 1/√N |
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Beschreibung: | Date Completed 26.04.2018 Date Revised 26.04.2018 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
ISSN: | 1520-5827 |
DOI: | 10.1021/acs.langmuir.6b03972 |