Fabricated Biobased Eucommia Ulmoides Gum/Polyolefin Elastomer Thermoplastic Vulcanizates into a Shape Memory Material

Abstract

Partially biobased thermoplastic vulcanizates (TPVs) with shape memory properties were prepared by in situ dynamic vulcanization of eucommia ulmoides gum (EUG) and polyolefin elastomer (POE). The cross-linked EUG phase dispersed in POE matrix acted as a framework structure throughout the POE phase, which limited irreversible deformation of POE and provided sufficient resilience force to drive the POE molecular chains to recover their initial shape. The shape memory results demonstrated that EUG/POE TPVs exhibited excellent shape memory properties with high shape fixity and shape recovery rate (all above 95%). The EUG with the dimensions of 0.4–1.6 μm dispersed in the POE matrix, and the more EUG phase resulted in large EUG aggregates. The cross-linked EUG phase considerably improved the permanent deformation of POE, and the tensile set linearly decreases from 134% to 4% with increasing EUG contents. The mechanical and shape memory properties of EUG/POE TPVs changed little after being reprocessed twice, exhibiting good reprocessability. All of these remarkable advantages make EUG/POE TPVs good candidates for shape memory materials.

Fully Biobased Shape Memory Thermoplastic Vulcanizates from Poly(Lactic Acid) and Modified Natural Eucommia Ulmoides Gum with Co-Continuous Structure and Super Toughness

“…DSC analysis was carried out to study the thermal properties of PLA/EUG-g-GMA TPVs. In the cooling scanning (Figure 7a), there was the glass transition of PLA at around 60 • C [36] and the crystallization peak of EUG-g-GMA ranging from −10 to 40 • C. For PLA/EUG-g-GMA TPVs, the glass transition temperature (T g ) of PLA shifted to a lower temperature while the crystallization peak area of EUG-g-GMA increased obviously with increasing EUG-g-GMA content (indicated by dot line). In the heating scanning (Figure 7b), endothermic peak at around 50 • C corresponded to the melting of crystalline zones in the EUG-g-GMA phase [14].…”

Bio‐based Eucommia ulmoides gum/low density polyethylene shape memory composites reinforced by zinc methacrylate

“…13,14 Eucommia ulmoides gum (EUG), a natural bio-polymer and isomer of natural rubber, exhibits plastic and rubber duality owing to its highly ordered molecular structure. 15,16 By tailoring the crosslinking structure, EUG can be easily utilized as thermal plastics, elastomers and SMMs. [17][18][19] The shape memory properties of partially crosslinked EUG have been associated with its crystalline/melting phase transition.…”

“…[17][18][19] The shape memory properties of partially crosslinked EUG have been associated with its crystalline/melting phase transition. 15,20 However, the semicrystalline crosslinked EUG suffers from a low deformation temperature as well as poor mechanical performance, which restricts its application as SMM.…”

A high toughness elastomer based on naturalEucommia ulmoidesgum

“…In most cases, EUG was blended with other materials, such as cispolyisoprene, [19][20][21][22] chlorobutadiene rubber, 23 cellulose, 24,25 poly(ε-caprolactone), 26 polylactide, 27 polypropylene, 28 to improve the properties of composites or was used to prepare shape memory materials. [29][30][31][32][33][34][35] How to obtain EUG-based elastomer as a substitute for NR has gradually attracted enough attention in recent years. In 1980s, Yan discovered a method to vulcanize EUG by utilizing special formulations and mixing conditions.…”

“…Therefore, almost no EUG was used alone in the rubber industry. In most cases, EUG was blended with other materials, such as cis‐ polyisoprene, 19–22 chlorobutadiene rubber, 23 cellulose, 24,25 poly(ε‐caprolactone), 26 polylactide, 27 polypropylene, 28 to improve the properties of composites or was used to prepare shape memory materials 29–35 …”