title: Novel rubbers from cationic copolymerization of soybean oils and dicyclopentadiene. 1. Synthesis and characterization.
abstract: Novel thermosetting copolymers, ranging from tough and ductile to very soft rubbers, have been prepared by the cationic copolymerization of regular (SOY) and 100% conjugated soybean oils (C(100)SOY) with dicyclopentadiene (DCP) catalyzed by Norway fish oil (NFO)-modified and SOY- and C(100)SOY-diluted boron trifluoride diethyl etherate (BFE). The gelation time of the reactions varies from 4 to 991 min at 110 degrees C. The yields of the bulk copolymers are essentially quantitative, while the yields of the cross-linked copolymers remaining after Soxhlet extraction with methylene chloride range from 69% to 88%, depending on the monomer stoichiometry and the catalyst used. (1)H NMR spectroscopy and Soxhlet extraction data indicate that these copolymers consist of a cross-linked soybean oil-DCP network plasticized by certain amounts of methylene chloride-soluble linear or less cross-linked soybean oil-DCP copolymers, unreacted oil, and some low molecular weight hydrolyzed oil. The molecular weights of these soluble fractions are in the range from 400 to 10,000 g/mol based on polystyrene standards. The bulk copolymers have glass transition temperatures ranging from -22.6 to 56.6 degrees C, while their tan delta peak values range from 0.7 to 1.2. Thermogravimetric analysis (TGA) indicates that these soybean oil-DCP copolymers are thermally stable below 200 degrees C, with 10% and 50% weight loss temperatures ranging from 280 to 372 degrees C and 470-554 degrees C, respectively. These properties suggest that these biobased thermosets may prove useful alternatives to current petroleum-based plastics and find widespread utility.
authors.affiliation: Department of Chemistry, Iowa State University, Ames, 50011, USA.
authors.forename: Dejan D
authors.initials: DD
authors.lastname: Andjelkovic
authors.forename: Richard C
authors.initials: RC
authors.lastname: Larock
mesh_terms: D001880:Boranes / Q000737:chemistry; D002412:Cations; D002849:Chromatography, Gas; D005395:Fish Oils / Q000737:chemistry; D006358:Hot Temperature; D006868:Hydrolysis; D007192:Indenes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D011108:Polymers / Q000138:chemical synthesis*; D012408:Rubber / Q000138:chemical synthesis* / Q000737:chemistry; D013024:Soybean Oil / Q000737:chemistry*; D013696:Temperature; D013818:Thermogravimetry
chemical_list: D001880:Boranes; D002412:Cations; D005395:Fish Oils; D007192:Indenes; D011108:Polymers; C021274:boron trifluoride; D013024:Soybean Oil; C004689:dicyclopentadiene; D012408:Rubber