Structural batteries (SBs) are a growing research subject worldwide. The idea is to provide massless energy by using a multifunctional material. This technology can provide a new pathway in electrification and offer different design opportunities and significant weight savings in vehicle applications. The type of SB discussed here is a multifunctional material that can carry mechanical loads and simultaneously provide an energy storage function. It is a composite material that utilizes carbon fibers (CFs) as electrodes and structural reinforcement which are embedded in a multifunctional polymer matrix (i.e., structural battery electrolyte). A feasible composite manufacturing method still needs to be developed to realize a full-cell SB. UV initiated polymerization induced phase separation (PIPS) has previously been used to make bicontinuous structural battery electrolytes (SBE) with good ionic conductivity and mechanical performance. However, UV-curing cannot be used for fabrication of a full cell SB since a full-cell is made of multiple layers of nontransparent CFs. The present paper investigates thermally initiated PIPS to prepare a bicontinuous SBE and an SB half-cell. In addition, the effect of curing temperature was examined with respect to curing performance, morphology, ionic conductivity, and mechanical and electrochemical performance. The study revealed that thermally initiated PIPS provides a robust and scalable process route to fabricate SBs. The results of this study are an important milestone in the development of SB technology as they allow for the SB fabrication for an actual application. However, other challenges still remain to be solved before this technology can be introduced into an application.

Reduced mass for improvements in system performance has become a priority for a wide range of applications that requires electrical energy and includes load-bearing components. Use of lightweight materials has been identified as key for successful electrification of future transport solutions. Structure, energy storage and energy distribution are usually subsystems with the highest mass contributions but energy storage and energy distribution devices are structurally parasitic. One creative path forward is to develop composite materials that perform several functions at the same time – multifunctional materials. Combining functions in a single material entity will enable substantial weight savings on the systems level.

One such concept is a structural battery, a material that simultaneously carry load and stores energy like a battery. Structural batteries employ carbon fibres as structural reinforcement and negative electrode and can also be used as current collectors to save additional weight.

A number of new physical phenomena when using carbon fibres as battery electrodes have been found which allows for further multi-functionality. These are all based on the fact that carbon fibres intercalated lithium ions as an electrode material. The ion intercalation creates a reversible longitudinal expansion of the carbon fibres which could be used for actuation and morphing. A piezo electrochemical effect couples the electrical potential of the fibre to the strain acting on it, which can be used for sensing purposes. By combining the expansion and the piezo electrochemical effect one can convert mechanical energy to electrochemical energy, providing an energy harvesting function. The long-term vision of this work is to create a composite material that carries load, stores electrical energy, senses its own state, morphs and harvests energy.

This work demonstrates a versatile and environmentally friendly route for the development of new orthogonal monomers that can be used for postfunctionalizable polymer networks. A monomer containing both vinyl ether (VE) and cyclic disulfide moieties was synthesized via enzyme catalysis under benign reaction conditions. The bifunctional monomer could be polymerized to form macromolecues with differing architectures by the use of either cationic or radical photo polymerization. When cationic polymerization was performed, a linear polymer was obtained with pendant disulfide units in the side chain, whereas in the presence of radical initiator, the VE reacted with the disulfide to yield a branched structure. The monomer was thereafter used to design networks that could be postfunctionalized; the monomer was cross-linked with cationic initiation together with a difunctional VE oligomer and after cross-linking the unreacted disulfides were coupled to Rhodamine-VE by radical UV-initiation

This work demonstrates a versatile and environmentally friendly route for the development of new orthogonal monomers that can be used for postfunctionalizable polymer networks. A monomer containing both vinyl ether (VE) and cyclic disulfide moieties was synthesized via enzyme catalysis under benign reaction conditions. The bifunctional monomer could be polymerized to form macromolecues with differing architectures by the use of either cationic or radical photo polymerization. When cationic polymerization was performed, a linear polymer was obtained with pendant disulfide units in the side chain, whereas in the presence of radical initiator, the VE reacted with the disulfide to yield a branched structure. The monomer was thereafter used to design networks that could be postfunctionalized; the monomer was cross-linked with cationic initiation together with a difunctional VE oligomer and after cross-linking the unreacted disulfides were coupled to RhodamineVE by radical UV-initiation.

A synthesis protocol was identified to produce covalent grafting of poly(dimethyl siloxane) from cellulose, based on prior studies of analogous ring opening polymerizations. Following this polymer modification of cellulose, the contact adhesion was anticipated to be modified and varied as a function of the polymer molecular mass. The synthetic details were optimized for a filter paper surface before grafting the polymer from bulk cellulose spheres. The adhesion of the unmodified and grafted, bulk cellulose spheres were evaluated using the Johnson-Kendall-Roberts (JKR) theory with a custom build contact adhesion testing setup. We report the first example of grafting poly(dimethyl siloxane) directly from bulk cellulose using ring opening polymerization. For short grafting lengths, both the JKR work of adhesion and the adhesion energy at the critical energy release rate (G(c)) were comparable to unmodified cellulose beads. When polymer grafting lengths were extended sufficiently where chain entanglements occur, both the JKR work of adhesion and G(c) were increased by as much as 190%. Given the multitude of options available to graft polymers from cellulose, this study shows the potential to use this type of cellulose spheres to study the interaction between different polymer surfaces in a controlled manner. [GRAPHICS] .

Transforming biomass derived components to materials with controlled and predictable properties is a major challenge. Current work describes the controlled synthesis of starcopolymers with functional and degradable arms from the Lignoboost (R) process. Macromolecular control is achieved by combining lignin fractionation and characterization with ring-opening copolymerization (ROCP). The cyclic monomers used are epsilon-caprolactone (epsilon CL) and a functional carbonate monomer, 2-allyloxymethyl-2-ethyltrimethylene carbonate (AOMEC). The synthesis is performed at ambient temperature, under bulk conditions, in an open flask, and the graft composition and allyl functionality distribution are controlled by the copolymerization kinetics. Emphasis is placed on understanding the initiation efficiency, structural changes to the lignin backbone and the final macromolecular architecture. The present approach provides a green, scalable and cost effective protocol to create well-defined functional macromolecules from technical lignins.

The performance of different esterification catalysts was studied for the use in synthesis of renewable polyesters from dimethyl itaconate (DMI), dimethyl succinate (DMS) and 1,4-butanediol (BD). Itaconic acid and derivatives such as DMI are interesting monomers because of their multiple functionalities and previous work has shown great potential. However, the multiple functionalities also pose challenges to avoid side reactions such as thermally initiated, premature, radical crosslinking and/or isomerization of the 1,1-disubstituted unsaturation. Additionally, the two carboxylic acids have inherently different reactivity. One key factor to control reactions with IA is to understand the performance of different catalysts. In this study, six esterification catalysts were investigated; immobilized Candida antarctica lipase B (CalB), titanium(IV)butoxide (Ti(OBu)4), p-toluenesulfonic acid (pTSA), sulfuric acid (H2SO4), 1,8-diazabicycloundec-7-ene (DBU), and 1,5,7-triazabicyclodec-5-ene (TBD). CalB and Ti(OBu)4 were selected for further characterization with appreciable differences in catalytic activity and selectivity towards DMI. CalB was the most effective catalysts and was applied at 60 °C while Ti(OBu)4 required 160 °C for a reasonable reaction rate. CalB was selective towards DMS and the non-conjugated side of DMI, resulting in polyesters with itaconate-residues mainly located at the chain ends, while Ti(OBu)4 showed low selectivity, resulting in polyesters with more randomly incorporated itaconate units. Thermal analysis of the polyesters showed that the CalB-catalyzed polyesters were semi-crystalline, whereas the Ti(OBu)4-catalyzed polyesters were amorphous, affirming the difference in monomer sequence. The polyester resins were crosslinked by UV-initiated free radical polymerization and the material properties were evaluated and showed that the crosslinked materials had similar material properties. The films from the polyester resins catalyzed by CalB were furthermore completely free from discoloration whereas the film made from the polyester resins catalyzed with Ti(OBu)4 had a yellow color, caused by the catalyst. Thus, it has been shown that CalB can be used to attain sustainable unsaturated polyesters resins for coating applications, exhibiting equally good properties as resins obtained from traditional metal-catalysis.