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Swelling and Mechanical Properties of Solution-Crosslinked Poly ( isobutylene ) Gels
| Content Provider | Semantic Scholar |
|---|---|
| Author | Durmaz, Selda Fank, Sinan Okay, Oguz |
| Abstract | Butyl rubber, which is commercially available since 1943, consists of poly(isobutylene) (PIB) chains containing small amounts of isoprene units. The structure of butyl rubber may be represented as follows, where n is a number between 20 to 35: Because of the low degree of unsaturation in butyl rubber, its vulcanization requires much more powerful accelerators than the natural rubber. 2] Due to extensive chain scission reactions occurring in the presence of peroxide initiators such as dibenzoyl peroxide, vulcanization of butyl rubber by free radicals cannot be carried out. For the preparation of heat resistant compounds, e.g., in cable insulation stocks, its vulcanization is carried out using dioximes. For exceptional heat resistant applications such as in tires, phenolic resins are used as the vulcanization agent. Recently, we have shown that butyl rubber can easily be crosslinked in an organic solution using sulfur monoFull Paper: We prepared several series of poly(isobutylene) (PIB) gels starting from butyl rubber in dilute toluene solutions using sulfur monochloride as a crosslinking agent. Solution and suspension-crosslinking techniques were used for the preparation of PIB gels in the form of rods, membranes, and beads in the size range of 1 to 3 mm. The gels were subjected to dynamic and equilibrium swelling measurements in toluene and cyclohexane as well as to the elasticity tests. Depending on the amounts of sulfur monochloride and butyl rubber in the crosslinking solution, PIB gels with different swelling capacities and elastic moduli were synthesized. The swelling ratio of the gels first increased rapidly with increasing swelling time but then decreased until an equilibrium was obtained. This unusual swelling behavior was accompanied with an increase of the elastic moduli of the gels during the swelling process. The results were explained with the postcrosslinking reactions taking place during the swelling process of PIB gels. By using the theory of equilibrium swelling, the number of segments in the network chains and the polymer-solvent interaction parameters were calculated for PIB gels prepared under various reaction conditions. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://web.itu.edu.tr/okayo/pdf/02macroselda.pdf |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | 1-Butanol Bead Dosage Form Benzoyl Peroxide Chemistry, Inorganic Computer programming Cross link Cyclohexane Edema Elasticity (data store) Encyclopedias Free Radicals Gel Handbook Handbooks Insulation Device Component Kind of quantity - Equilibrium Pebibyte Peroxides Phenol formaldehyde resin Poly A Polymer Primed In Situ Labeling Resins, Plant Rod Photoreceptors Selenium Solutions Suspensions Technetium Tc 99m Sulfur Colloid Tellurium The New York Times Tissue membrane Toluene Wilfried Brauer butyl rubber isobutylene isoprene macromolecule poly ICLC |
| Content Type | Text |
| Resource Type | Article |
