Measurements of freezing-point depression to evaluate rubber network structure. Crosslinking of natural rubber with dicumyl peroxide

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 45; no. 5; pp. 544 - 556
• Main Authors: Valentín, J. L., Fernández-Torres, A., Posadas, P., Marcos-Fernández, A., Rodríguez, A., González, L.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.03.2007; Wiley
• Subjects: Applied sciences; Exact sciences and technology; freezing point depression; Natural polymers; Natural rubber; networks; Physicochemistry of polymers; rubber; vulcanization; Differential scanning calorimetry; Molecular structure; Thermal method; Stress strain relation; Crosslink density; Mechanical properties; Natural rubber; Experimental study; networks; Structure processing relationship; Vulcanization; Mechanical method; Spatial distribution; Investigation method; Vulcanizate; rubber; Property structure relationship; freezing point depression; Organic peroxide
• ISSN: 0887-6266; 1099-0488
• DOI: 10.1002/polb.21060

An experimental approach based on the freezing‐point depression of a solvent in a swollen gel has been developed to characterize the structure of rubber networks. This property depends on the conditions required for the formation of crystalline nuclei, which are limited by the elastomer network restrictions. Information about the functionality, spatial distribution, and number of crosslinks can be obtained by the use of this easy and ready experimental method. Application of the tube model of rubber elasticity in the uniaxial stress–strain experiments of natural rubber samples vulcanized with dicumyl peroxide yields the characteristic parameters of the rubber networks, which are in concordance with the network structures predicted by the freezing point method. Finally influence of vulcanization conditions in network structure and its relationship with the mechanical properties was evaluated. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 544–556, 2007