Evaluation of 18 Year-Service Lifetime of NR-SBR Lining
Our recent high resolution core level and valence level X-ray photoelectron spectra (XPS) of Natural-Styrene Butylene Rubber (NR/SBR) demonstrated much narrower linewidths than previously obtained on rubbers or other polymer coatings. This improvement is due to low-current, low-energy beam flood gun charge compensation on non-conductor rubbers. The different charging has compensated on the rough surface and in the bulk of sponge structure in depth 50 Å of rubber sample. Despite residual charging has occurred on the surface which is apparent in C1s and O1s shoulder on its right side of the peak shape. Carbon groups such as C-H, C-C, C=C cannot be easily differentiated by their principal C(1s) peak chemical shift. Carbon black fillers seem to behave quite differently in the rubber-curing reaction. The stability of vulcanized rubber with sulfur curing system was studied in components of C(1s), O(1s), S(2p) regions which represented appropriate estimation of changes of crosslinked with sulfide bonds on rubber surface. The connection between the Shore hardness of rubber and the presence of carbonyl and sulphonyl groups was apparent. A model has been proposed for the degradation of the crosslinking density of rubber after long term exposure.
Yungang Li, Pengcheng Wang, Liqun Ai, Xiaoming Sang and Jinglong Bu
J. Racek and E. Kalabisová, "Evaluation of 18 Year-Service Lifetime of NR-SBR Lining", Advanced Materials Research, Vols. 291-294, pp. 2914-2917, 2011