Covalent crosslinks turn natural Eucommia ulmoides gum/polybutene‐1 composites into multiple shape memory materials

Abstract

A series of shape memory natural Eucommia ulmoides gum (EUG)/polybutene‐1 (PB‐1) composites were developed based on polymer blending. It was revealed that covalent crosslinks turned typical “sea‐island” phase morphology in the EUG/PB‐1 blend into a chemical co‐continuous structure, which played a vital role in promoting mechanical performances and fulfilling multiple shape memory effect dominated by the two well‐separated crystalline and melting phase transitions. Although the increase in cross‐linking density was a disadvantage to mechanical performances and shape fixing, the composite with more covalent crosslinks displayed better shape recovery capacity. The EUG/PB‐1 composite crosslinked by 0.4 phr diycumyl peroxide (DCP) displayed the highest shape fixing capacity, while the best shape recovery ability was given by that crosslinked by 1.6 phr DCP. The findings would provide a new technique to develop intelligent materials applied in smart packaging and hot‐shrinkable products.

Inverse Vulcanization Polymer-Modified Eucommia ulmoides Gum with Enhanced Shape Memory Capability and Sound Absorption Property

“…A shape memory polymer is usually composed of a fixed phase that remembers the original shape and reversible phase that achieves temporary shape memory and recovery by external stimulation. In EUG-SP-x , the crystalline zones of EUG acted as the reversible phase and the crosslinking networks acted as the stationary phase. , EUG and EUG-SP-x were first heated above their T m s for softening and deforming, and their temporary shapes were solidified by cooling to room temperature; the results are shown in Figure a. It can be clearly seen that R r values of samples increase with the increase of temperature and SP content.…”

Shape memory polylactic acid/modified Eucommia ulmoides gum thermoplastic vulcanizates based on excellent interfacial adhesion and co‐continuous structure

“…Both the disorientation of PLA molecules and the elastic retraction of the EEUG phase worked together based on the co‐continuous structure and excellent interfacial adhesion to drive shape recovery of the TPVs, resulting in higher R r . In addition, the increase in R r with increasing DCP content might result from enhanced elastic retraction of the EEUG phase due to the increased crosslinking degree 50 …”

“…In addition, the increase in R r with increasing DCP content might result from enhanced elastic retraction of the EEUG phase due to the increased crosslinking degree. 50…”

Tea‐polyphenols mediated interfacial modifier to integrate reinforcement, reprocessability, and shape memory properties into rubber/carbon black composites via coordination bonds

“…As smart materials, shape memory polymers (SMPs) can fix temporary shapes and recover to permanent shapes by crosslinking structures and switching segments, which have displayed great potentials in medical devices and sensors. [42][43][44][45][46] Although conductive carbon blacks were used, TP@C displayed poor conductivity for rubber composites owing to strong barriers of TP absorbate, which makes it harder to apply in electrical sensors. [47] Considering dynamic coordination interfaces and crosslinks of Zn10TP@Cx, they should possess thermally triggering shape reconfiguration behaviors as SMPs did.…”

“…[33][34][35][36][37][38][39] The NBR/TP@C composites can be reprocessed and reshaped at the elevated temperatures. Moreover, these dynamic interface bonds and crosslinks endowed the composites shape memory properties, [40][41][42][43][44][45][46] showing the functionality of TP@C for rubber materials and great application potentials in smart material fields.…”