Designing a fully biobased monomer to build a series of degradable thermosets is of great significance for sustainable development and environmental protection. In this work, a fully biomass based monomer (EUIT) was designed and synthesized from itaconic acid (IA) and eugenol (EU). Thiol–ene crosslinked polymers (TCPs) were prepared by changing the degree of the thiol functionality from 2 to 4 via a VOC-free thiol–ene click reaction. Also, the thermal, thermomechanical, and mechanical properties of these TCPs were investigated. The results showed that EUIT/4SH possessed the best comprehensive properties, that is, the glass-transition temperature (T_g) was up to 74.0 °C, and the mechanical properties including tensile strength and modulus were 58.6 MPa and 1.5 GPa, respectively, which were the maximum values compared with those in the reported investigations. Besides, these TCPs exhibited good degradable properties because of the inherent functional groups such as the ester groups in EUIT. Thus, this study provides a new method to prepare a fully biobased monomer and produce a series of degradable thermosets which are expected to be advanced biomedical materials, flexible electronic materials, etc.

Multi-responsive form-stable phase change materials (FSPCMs) can convert various forms of energy to latent heat for storage and have attracted extensive attention. Superhydrophobic surfaces are garnering constant interest and can improve the long-term solar energy utilization and environmental adaptability of multi-responsive FSPCMs. However, a simultaneous demonstration of such functional integration is still a challenge due to the restriction of supporting materials. Herein, crosslinkable bottlebrush crystalline polysiloxanes (Si_0.75-18-x) having strong intermolecular forces with paraffin are used as super-flexible supporting materials to encapsulate paraffin via self-assembly and 3D networks. Multi-responsive phase change films are directly fabricated by spray-coating Si_0.75-18-x/paraffin solution with a dispersion of multi-walled carbon nanotubes (MWCNTs), followed by in situ curing. Herein, apart from fine affinity with Si_0.75-18-x, MWCNTs simultaneously enable tailored surface roughness, thermal/electrical conductivity and photo-thermal conversion. The proof-of-concept material (Si_Pa-160/CNTs-3) shows excellent latent heat, superhydrophobicity, photonic/thermal/electrical responses, shape variation ability, thermal recycling properties and stability. Strikingly, Si_Pa-160/CNTs-3 coatings can be large-scale constructed on varied substrates and have the potential for use in wearable devices, intelligent buildings, electronic devices and so on. This study broadens the advanced application and creates a whole new development platform for FSPCMs in energy conversion and storage.

Room-temperature-use phase change materials (PCMs) are of vital importance in combining the sustainable development of energy with human comfort. Here, a series of novel epoxy-based polymeric solid–solid PCMs (SSPCMs) were facilely prepared by UV grafting 1-octadecanethiol (ODT) onto an allyl-based epoxy resin (DADGEBA) via thiol–ene click chemistry followed by the epoxy–amine thermal curing process. Therefore, the grafted ODT can be tightly locked in a reliable three-dimensional crosslinking network of the epoxy resin, which provides the PCMs with excellent shape-stable property. Phase change and mechanical properties characterized by DSC, DMA, hardness test, and tensile test can be easily tuned by adjusting the mass ratio of DGEBA and the ODT-grafted-DADGEBA product (D18), which was characterized by FTIR and NMR. XRD and POM analyses proved the crystallinity of EP_D18-X PCMs. The structure and morphology of the EP_D18-X PCMs were characterized by visual images, SEM, and POM analyses. Microphase separation was observed in all the EP_D18-X PCMs, and an obvious phase separation was observed in the EP_D18-25 system. However, the phase separation gradually disappeared with the increasing of the D18 content. Thermal recycling tests showed that EP_D18-X PCMs can remain stable after 50 DSC thermal cycles. Due to the unique strong encapsulated epoxy curing networks, EP_D18-X PCMs have excellent thermal stability with the onset degradation temperature higher than 250 °C. Tunable EP_D18-X systems can be applied for room-temperature-use thermal energy storage applications such as buildings, thermoregulated fabrics, and so on.