Characterization of silica modified with silanes by using thermogravimetric analysis combined with infrared detection
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Tire treads with reduced rolling resistance and increased wet grip can be achieved by coupling hydrophilic silica to hydrocarbon rubber by using an alkoxysilane. The silica surface was modified by reaction with a wide range of coupling and non-coupling silanes. The chemistry and extent of these silanizations were elucidated using thermogravimetric analysis (TGA) combined with infrared detection. The silane grafting efficiencies were typically 52–72%, but efficiencies were lower in the bulkier [3-(di-(tridecyloxypenta(ethyleneoxy))ethoxysilyl]propyl mercaptan. However, the silica surface coverage increases with increasing size of the silane. Grafting efficiencies were lower with higher silane loadings. In the TGA, ethoxy and methoxy groups are displaced from the grafted silanes mainly at moderate temperatures (up to about 495 °C) to form siloxane bridges. Over a similar temperature range, the weaker S–S bonds present in bis(3-triethoxysilylpropyl) tetrasulfide (TESPT)- or bis[3-(triethoxysilyl)propyl] disulfide (TESPD)-modified silica are cleaved, leading to weight losses from TESPT or TESPD bound at one end to the silica and from TESPT bound at both ends. The remaining weight losses from bound silanes occurred mainly at higher temperatures. In the commercial silanized silica Coupsil 8113, TGA indicates that about two of three ethoxy groups in each triethoxysilane were lost during the silanization process.
Date Issued
2019-04-01
Date Acceptance
2018-02-28
Citation
Rubber Chemistry and Technology, 2019, 92 (2), pp.237-262
ISSN
0035-9475
Publisher
Rubber Division, ACS
Start Page
237
End Page
262
Journal / Book Title
Rubber Chemistry and Technology
Volume
92
Issue
2
Copyright Statement
© 2018 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Rubber Chemistry and Technology, after peer review and technical editing by the publisher. To access the final edited and published work see https://dx.doi.org/10.5254/rct.18.82626
Subjects
Science & Technology
Physical Sciences
Polymer Science
POLY(ETHYLENE OXIDE)
COUPLING AGENT
MECHANICAL-PROPERTIES
SURFACE MODIFICATION
CONTAINING MOLECULES
THERMAL-DEGRADATION
POLYETHYLENE OXIDE
KINETICS
THERMOCHEMISTRY
TEMPERATURE
Polymers
Publication Status
Published
Date Publish Online
2018-05-30