Renewable Terpene Derivative as a Biosourced Elastomeric Building Block in the Design of Functional Acrylic Copolymers

Abstract

In order to move away from traditional petrochemical-based polymer materials, it is imperative that new monomer systems be sought out based on renewable resources. In this work, the synthesis of a functional terpene-containing acrylate monomer (tetrahydrogeraniol acrylate, THGA) is reported. This monomer was polymerized in toluene and bulk via free-radical polymerizations, achieving high conversion and molecular weights up to 278 kg·mol–1. The synthesized poly­(THGA) shows a relatively low T g (−46 °C), making it useful as a replacement for low T g acrylic monomers, such as the widely used n-butyl acrylate. RAFT polymerization in toluene ([M]0 = 3.6 mol·L–1) allowed for the well-controlled polymerization of THGA with degrees of polymerization (DP n ) from 25 to 500, achieving narrow molecular weight distributions (D̵ ≈ 1.2) even up to high conversions. At lower monomer concentrations ([M]0 = 1.8 mol·L–1), some evidence of intramolecular chain transfer to polymer was seen by the detection of branching (arising from propagation of midchain radicals) and terminal double bonds (arising from β-scission of midchain radicals). Poly­(THGA) was subsequently utilized for the synthesis of poly­(THGA)-b-poly­(styrene)-b-poly­(THGA) and poly­(styrene)-b-poly­(THGA)-b-poly­(styrene) triblock copolymers, demonstrating its potential as a component of thermoplastic elastomers. The phase separation and mechanical properties of the resulting triblock copolymer were studied by atomic force microscopy and rheology.

Triblock polyester thermoplastic elastomers with semi-aromatic polymer end blocks by ring-opening copolymerization

“…17 In terms of so-block polyesters, there are a range of options, many of which are also bio-derived, and covering T g values from À60 to À25 C. For example, the ring-opening polymerization of menthide (derived from mint), 26 3-decalactone (derived from castor oil), 21,27,28 6methyl-3-caprolactone, 29 b-methyl-d-valerolactone (derived from glucose), 19 3-caprolactone (widely regarded as degradable) 20 or g-methyl-3-caprolactone are all reported. 24 Other bio-derived so block polymers are known, but not all are degradable, for example by the polymerization of terpenes, 30,31 fatty acids 32 or lignin. 33 One striking problem is the rather narrow range of bioderived hard block materials: almost all studies apply polylactide, PLA (derived from corn starch).…”

A role for terpenoid cyclization in the atom economical polymerization of terpenoids with sulfur to yield durable composites

“…A wide range of composites employing terpenoid or derivative monomers have been explored for the preparation of polymers with the aim of elucidating renewably-sourced alternatives to petrochemical olefins. [2][3][4] Organosulfur polymers and composites have attracted some attention as potentially robust and recyclable alternatives to petrochemical polyolefins as well. Sulfur is a surplus by-product removed from fossil fuels to prevent the release of sulfur combustion products into the atmosphere, so its valorisation has attracted some interest.…”

Caryophyllene as a Precursor of Cross-Linked Materials

“…[4][5][6][7][8][9][10] Terpenes and terpenoides have drawn considerable attention as potential starting precursors in the synthesis of elastomers. [11][12][13][14][15][16][17][18] Studies on the synthesis of elastomers from pinene, myrcene, and limonene [19][20][21][22][23][24] can be readily found in the scientific literature and some commercially available resins and adhesives (e.g. Piccolyte®) derived from polypinenes are already reported.…”