Viscoelastic and mechanical properties of large- and small-particle natural rubber before and after vulcanization. (September 2018)

• Record Type: Journal Article
• Authors: Sriring, Manus; Nimpaiboon, Adun; Kumarn, Sirirat; Sirisinha, Chakrit; Sakdapipanich, Jitladda; Toki, Shigeyuki
• Is Part Of: Polymer testing. Volume 70(2018)
• Page Start: 127
• Page End: 134
• Publication Date: 2018-09
• Subjects: Natural rubber -- Skim rubber -- Large rubber particle -- Small rubber particle -- Vulcanization -- Green properties -- Viscoelastic properties; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2018.06.026
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: Insights into viscoelastic and mechanical properties of large- and small-particle natural rubber (NR) were gained for developing new rubber products. NR latex was first subjected to centrifuging to separate large rubber particles (LRP) and small rubber particles (SRP). The LRP and SRP solid rubbers were prepared to investigate their molecular weight characteristics and mechanical and viscoelastic properties. Before vulcanization, the LRP rubber was found to be better in both tensile strength and elasticity, as a result of natural branch-point networks formed by aggregation of phospholipid groups at the terminating end (α end) of the LRP rubber chains. After vulcanization, the SRP vulcanizate was, on the other hand, found to perform better in all respects. This could be explained by the accelerating effect from the proteins bound to the initiating end (ω end) of the SRP rubber chains in the crosslinking process during vulcanization. Highlights: Insights into properties of small- and large-particle natural rubber were acquired. Pure large and small rubber particle latices were prepared separately. Their basic characteristics, mechanical and viscoelastic properties were studied. Green properties of rubber from large rubber particle were better than that from small one. After curing, rubber from small rubber particle were greater than that from large one.