Synthesis of crystallizable comb‐like oligomers by coupling of stearyl acrylate to butadiene oligomers via ene reaction and the influence of side‐chain order on the network formation by autoxidation

Abstract

The kinetics of the ene reaction of stearyl acrylate with polybutadiene oils in the temperature range of 180 to 220°C is described. The ene reaction was found to be of pseudo 1st order with respect to stearyl acrylate because of the excess of polybutadiene double bonds. The rate constants correlate with the reaction temperature according to the Arrhenius law. The products show typical side-chain crystallization, which has a strong influence on the viscosity and the autoxidation kinetics of the unsaturated polymeric backbone. Just below the crystallization temperature of the side chains the network formation by autoxidation is much slower than above the melting point.

Crosslinkable Polyphenols from Urushiol Analogues

“…A similar behavior was observed in the oxidation of a polybutadiene derivative under air. [28] All the above results suggest that the crosslinking mechanism of the present polymer is similar to that of the oil autoxidation. [7] Conclusion New crosslinkable polyphenols were synthesized by an oxidative polymerization of urushiol analogues having an unsaturated group, which were obtained by regioselective esterification using lipase as catalyst.…”

Alder ene functionalization of polyisobutene oligomer and styrene-butadiene-styrene triblock copolymer

“…The styrene-butadiene random copolymer (SBR) and the poly(styrene-b-butadiene-b-styrene) (styrene-butadienestyrene triblock copolymer, SBS) may be functionalized by enophiles through the Alder ene mechanism involving preferentially the vinyl side chains of the 1,2-butadiene units as for PB [10,15] and EPDM [1,16]. The Alder ene functionalization of SBS with MAH or diethyl maleate (DEM) as enophiles (Scheme 2) can allow the preparation of modified polyolefins containing different amounts of polar groups [17] without using free radical initiators.…”

“…Particularly, polyisobutene (PIB) [5][6][7][8][9] and polybutadiene (PB) [10] have been efficiently functionalized in the melt with maleic anhydride (MAH).…”

Thermal Annealing of High cis-1,4-Polybutadiene/Octadecyl Acrylate Blends as a One-Step Process for Fabricating Shape Memory Polymers

“…18,19 This present work follows the previous reports of Luchtenberg et al who showed the grafting of ODA to PB by an Alder-ene reaction. 23 They observed no gelation when they heated PB (M n = 1700 g/mol, 75 mol % 1,4-cis, 24 mol % 1,4trans, and 1 mol % vinyl) with ODA in the presence of N,Ndiphenyl-p-phenylenediamine, and acetylacetone in a dark reaction vessel under a nitrogen atmosphere at 180 °C for 25 h. However, in this current study, a higher MW PB (M n = 234,322 g/mol) was used where gelation occurs due to a thermally driven cross-linking reaction along with simultaneous ODA grafting of PB, resulting in a cross-linked graft network mixed with ODA crystals capable of exhibiting shape memory properties. The shape memory properties (especially shape recovery) of this grafted elastomeric network improved compared to the previous peroxide cured ODA/PB blend and is attributed to the more complete incorporation of PB into the elastic network, preventing the presence of viscoelastic material that can stress-relax in the programmed or deformed state limiting the shape recovery.…”