Abstract

Gel permeation chromatography (GPC), nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis techniques were used to study the molecular characteristics of six commercially available styrene-butadiene-styrene (SBS) block copolymers which are mostly used for modifying bitumen. The cis-1,4, trans-1,4, and 1,2-vinyl units in the polybutadiene (PB) parts and the styrene contents of the SBS block copolymers were investigated by means of 1H-NMR spectra. In addition carbon and hydrogen contents were estimated using 1H-NMR measurements. These estimated values were confirmed using the results of elemental analysis (EA). The glass transition temperatures (Tg) of SBS block copolymers were obtained using differential scanning calorimetry (DSC). The SBS block copolymers used in this study have different structural properties such as molecular weight and linearity. However, it is observed that the Tg-onset values are directly proportional to the percentage of the 1,2-vinyl units and inversely proportional to the percentage of the trans-1,4 units in the SBS block copolymers.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.