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Polyacrolein derivatives can be obtained from polyacrylates without the use of the toxic and volatile acrolein monomer.

Biomass, a renewable carbon source which can be processed using biorefinery system as an alternative of the conventional petroleum-based refineries. Aromatic precursor molecule synthesis involves chemical synthesis of fossil-fuel-based starting materials, such as benzene and xylene. These energy-intensive processes are usually producing many byproducts along with the desired molecule. If aromatic molecules can be extracted from natural resources involving minimum chemical conversions, that can be advantageous. Most of the reported approaches are expensive in nature and the outcomes with lower yield. Microbial fermentation of the lignocellulosic derivatives are ideal to establish sustainable society. In this chapter, we will focus on the aromatic building block preparations starting from nonedible feedstock such as kraft pulp. Aromatic aminobenzoic acid (3-amino-4-hydroxybenzoic acid) preparation from renewable resources and its use in various polymer preparations, such as polyaniline, polyester, and polybenzazole will be discussed here.

Ultrahigh thermoresistant polybenzimidazole films with uniform pores and hard craters on the surface were prepared by a silica template method. The pore and crater formation enhanced elongation and Young's modulus.

Bio-based polymer materials having great potential due to the depletion of fossil-fuel resources have been applied as single-use and medicinal materials but their low thermomechanical resistance have limited wider applications. Here, ultrahigh thermoresistant bio-based terpolymers with a low dielectric constant, comprising polybenzimidazole and poly(benzoxazole

Carbon fiber (CF) is widely used in the preparation of carbon-fiber-reinforced polymer composites (CFRP) in which it is combined with epoxy resin due to its good mechanical properties. Thermosetting bisphenol A epoxy resin, as one of the most common polymer materials, is a non-renewable resource, leading to a heavy environmental burden and resource waste. To solve the above problems and achieve high mechanical and thermal properties comparable to those of bisphenol A, herein, a high-performance, degradable and recyclable bio-based epoxy resin was developed by reacting the lignin derivative vanillin with 4-amino cyclohexanol via Schiff base. This bio-based epoxy resin showed a Young’s modulus of 2.68 GPa and tensile strength of 44 MPa, 36.8% and 15.8% higher than those of bisphenol A epoxy, respectively. Based on the reversible exchange reaction of the imine bond, the resin exhibited good degradation in an acidic environment and was recoverable by heat treatment. Moreover, the prepared epoxy resin could be used to prepare carbon fiber (CF)-reinforced composites. By washing off the epoxy resin, the carbon fiber could be completely recycled. The recovered carbon fiber was well preserved and could be used again for the preparation of composite materials to realize the complete recovery and utilization of carbon fiber. This study opens a way for the preparation of high-performance epoxy resin and the effective recycling of carbon fiber.

To synthesize a high-performance biopolyimide bioplastic from lignocellulosic feedstock, Escherichia coli was metabolically engineered to produce 4-amino-L-phenylalanine (4APhe) as a diamine monomer. A high-biomass sorghum cultivar was used as the...

The balance between high mechanical properties and strong adhesion strength is crucial in designing and preparing a bio-based hydrogel adhesive for wound closure. Although the adhesion performance of bioadhesives has been remarkably improved by modification with catechol groups, their mechanical properties are yet to meet the biomedical requirements. In this study, mussel-inspired epoxy bioadhesives (CSD-PEG) were synthesized based on catechol-modified chitosan oligosaccharide (CSD) and polyethylene glycol diglycidyl ether (PEGDGE) through nucleophilic substitution. Notably, the CSD-PEG adhesive showed high mechanical and adhesion strengths, which were up to 50.7 kPa and 136.7 kPa, respectively. It was confirmed that a certain amount of the epoxy and catechol groups provided multiple interfacial interactions among the adhesives, substrates, and polymer chains for enhancing the performance of adhesives. The adhesives showed good binding and repairing effects for wound closure and favorable biocompatibility in vivo. The prepared CSD-PEG adhesives are expected to be a promising candidate for surgical tissue repair, wound closure, and tissue engineering fields. Statement of significance Current reported adhesives composed of biopolymers generally suffer from poor mechanical properties or weak tissue adhesiveness. Therefore, to achieve simultaneously high mechanical and adhesion properties in a bio-based adhesive for wound closure is a big challenge. In this study, mussel-inspired adhesive hydrogels (CSD-PEG) were prepared based on catechol-modified chitosan oligosaccharide (CSD) and polyethylene glycol diglycidyl ether (PEGDGE). The tensile strength and adhesive strength of CSD-PEG on porcine skin reached 50.7 kPa and 136.7 kPa, respectively, which were higher than those for most reported biopolymeric adhesives, mainly due to the multiple interfacial interactions between the catechol and epoxy groups. The CSD-PEG bioadhesives also showed good binding and repairing effects for wound closure and tissue regeneration in vivo.

Biobased diamines with unique bending angles, β- and δ-type truxinic acids, were prepared from functionalized 4-nitrocinnamic acid derivatives via solid-state photodimerization and further chemical...

The relationship between the magnetorheological effect and the void ratio for a polyurethane magnetic elastomer with voids was investigated using a dynamic viscoelastic measurement under a magnetic field of 500 mT. The magnetic elastomer contains iron particles with a diameter of 235 μm at a concentration of 85 wt% (volume fraction: 0.43). The void ratio defined using the volume of vacancies in the non-filled volume of magnetic particles was increased by reducing the amount of polyurethane up to a maximum void ratio of 0.56. The storage modulus of the magnetic elastomer without voids was 1.5 × 10

The biological functions of polysaccharides are influenced by their chemistry and chain conformation, which have resulted in various functional applications and new uses for polysaccharides in recent years. Sacran is an intriguing ampholytic polysaccharide with several key properties such as metal adsorption, anti-inflammatory nature, and transdermal drug-carrying capacity. It has an extremely high molecular weight over 10

A series of biobased polyimides bearing a structure derived from a predetermined tetracarboxylic dianhydride was synthesized. By ionizing the COOH group of the side chain with potassium hydroxide, four kinds of polyimides were solubilized in water, and the water-soluble polyimides were cast onto films over an aqueous solution, leading to higher optical transparency than that of non-water-soluble polyimides. 1H nuclear magnetic resonance measurements of the polyimides revealed no residual reactants from the polymerization process or side-chain modification. Partial crosslinking of the water-soluble polyimide chains by condensation of the carboxylate side chain with an amino acid-based diamine such as 4-aminophenylalanine or 4,4′-diamino-α-truxillic acid induced the formation of polyimide hydrogels. The remaining COOK groups of the obtained hydrogel were protonated/deprotonated by changing the pH, accompanied by reversible shrinking and swelling. In this study, novel water-soluble polyimides and hydrogels were synthesized and evaluated. The water-soluble polyimides were synthesized from biobased 4-aminocinnamic acid dimer and appropriate tetracarboxylic dianhydrides by reaction with aqueous potassium hydroxide. A polyimide hydrogel was prepared using a crosslinking agent with 4-aminophenylalanine or 4-aminocinnamic acid dimer, which are also biobased amino acids, resulted in a fully biobased polyimide hydrogel. This hydrogel exhibits stimulus responsiveness, accompanied by a pH-dependent volume change because of the effect of carboxylate group derived from the polyimide side chain and crosslinking agent.

Cinnamate-based polyesters were synthesized, including poly(4-hydroxycinnamic acid), poly(4-hydroxy-3-methoxycinnamic acid), poly(3-hydroxycinnamic acid) (P3HCA), and hyperbranched poly(3,4-dihydroxycinnamic acid) (PdHCA). These materials were further processed into hard and dry membranes by casting and underwent photoreactions by ultraviolet (UV) light. The photodeformation behavior of the linear and hyperbranched polyester containing membranes with cinnamate derivatives in the main chain was observed macroscopically and microscopically. The PdHCA and P3HCA membranes were amorphous and exhibited photodeformations. The PdHCA surface visibly contracts, which is a typically observed phenomenon in photoresponsive polymers; however, the P3HCA surface showed a unique photoexpansion behavior. Time-resolution infrared spectroscopy of the P3HCA film revealed trans-to-cis isomerism in the polymer main chains that bent convexly as a result of photoexpansion of the UV-irradiated regions. Furthermore, photomasking created a micropattern on the P3HCA film, which supported the photoexpansion mechanism of the P3HCA film.

In this prelude study, the gellan gum/kenaf core fiber (KCF) biocomposite films were fabricated with the addition of imidazolium-based ionic liquids such as 1-butyl-3-methylimidazolium chloride (Bmim Cl), 1,3-dimethylimidazolium methylsulphate (Dmim MeSO4), 1-ethyl-3-methylimidazolium acetate (Emim Ac), and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (Emim OTf). The fabrication of the biocomposite films was carried out by mixing KCF and the ionic liquids in an aqueous solution, followed by dissolution of gellan gum in the same solution at a temperature of 90°C. The mixed solution was gelled at room temperature, and the formed gel was dried in an oven at 40°C for 48 hours to obtain a freestanding biocomposite film. The fabricated films were characterized by using a universal testing machine to acquire tensile properties. The tensile test results indicated that the biocomposite film added with Emim Ac possesses a higher tensile extension at maximum (up to 24%) than the biocomposite film without ionic liquid (added with glycerol). In addition, the biocomposite film added with Emim OTf has a higher tensile modulus at maximum (up to 758%) compared to the biocomposite film without ionic liquid. In conclusion, the tensile properties of the gellan gum/KCF biocomposite films can be improved with the addition of Emim-based ionic liquids with different counter anions.

Graphite has been the conventional lithium-ion anode for the negative electrode for the past three decades. One of the major challenges for graphite anodes is the exfoliation of graphite framework ...

An aspartame-based AB-type diketopiperazine monomer, cyclo(L-aspartyl-4-amino-L-phenylalanyl) (ADKP), was synthesized and subsequently utilized in the polycondensation of homo-polyamides with high molecular weights. By using various amino acids, dicarboxylic acids, and diamines, random DKP-based copolymers were also synthesized. The self-assembly properties of ADKP and poly(cyclo(L-aspartyl-4-amino-L-phenylalanyl)) (PA1) were studied via the solvent displacement method. Notably, PA1 self-assembled into particles with various morphologies in different solvent systems, such as irregular networks, ellipsoids, and hollow particles. The morphological transformation was also confirmed by dropping acetone and toluene onto the PA1 particles. Furthermore, infrared spectra and Hansen solubility parameters of PA1 and different solvents revealed the particle formation mechanism, which provided more insights into the relationship between the morphology and strength of the hydrogen bonding of each solvent.

To shift from a petroleum-dependent society to a sustainable society using eco-friendly materials, polysaccharides from natural products are important candidates as alternative materials. We have researched one cyanobacterial polysaccharide, “sacran”, which is extracted from Aphanothece sacrum. In this review, the unique characteristics and structures of sacran and the preparation of liquid crystal gels are introduced: polymer properties such as megamolecular weight, that is, a weight > 107 g/mol; characteristic viscosity; liquid crystallinity (LC); fiber structures on the nanometer/micrometer scale; gel formation with heavy metal ions; photoshrinking in gels composed of metal ions; anisotropically swelling gels; orientation upon drying of the air-LC interface; meniscus splitting; and membrane formation with uniaxial orientation, which are the results of self-organization. These matters are discussed particularly from the perspectives of polymer science, colloidal science, gel science, etc. We expect that sacran will be applicable in a variety of fields, such as tissue engineering, pharmacodynamics, and biomedical materials, with possible contributions to the development of a sustainable material society. To shift from a petroleum-dependent society to a sustainable society using eco-friendly materials, polysaccharides from natural products are important candidates as alternative materials. We have researched one of the cyanobacterial polysaccharides, “sacran,” which is extracted from Aphanothece sacrum. In this review, the unique characteristics, structures, and preparation of sacran LC gels are introduced. These matters are discussed especially from the perspectives of polymer science, colloidal science, gel science, etc. We hope that sacran will be used in a variety of fields, such as tissue engineering, pharmacodynamics, and biomedical materials, with possible contributions to the development of a sustainable material society.

In this preliminary study, kenaf core fiber (KCF) was utilized as a natural filler for the preparation of the gellan gum/KCF biocomposite films. The films were prepared by casting gellan gum solutions containing glycerol and KCF, followed by gelation and drying. The weight ratio of gellan gum and glycerol was fixed at 2:3, while the content of KCF varied from 6 to 15 wt.% relative to the weight of gellan gum. The tensile properties of the prepared films have been determined by using a universal testing machine. The tensile test results demonstrated that the tensile extension and tensile energy at break of the biocomposite films have significantly increased with the incorporation of KCF. Nevertheless, the tensile stress and tensile modulus at maximum load have drastically decreased with the increase of KCF content. This study implied that the incorporation of KCF had enhanced the ductility of the gellan gum/KCF biocomposite films and at the same time, reduced the stiffness of the films.

A highly effective aqueous lubrication strategy employing electrostatic assembly of a negatively charged ultrahigh molecular weight natural polysaccharide named "sacran" and a positively charged poly[2-(methacryloyloxy)ethyltrimethylammonium chloride] (PMTAC) brush was investigated. The PMTAC brush was compressed through the adsorption of sacran to produce the layered structure of a PMTAC brush/sacran hybrid bottom layer and a poorly hydrated sacran top layer. The dynamic friction coefficients of the PMTAC brush were drastically reduced in salt-free sacran aqueous solutions, and the lubrication mode transition from the brush-lubrication regime to hydrodynamic lubrication was promoted. The electrostatic assembly was inhibited by the addition of NaCl into the lubricant solutions, leading to the loss of the lubrication effect. The hydrodynamic lubrication would be encouraged by the local viscosity enhancement at the friction boundary due to the poorly hydrated and highly viscous PMTAC brush/sacran hybrid film produced by the spontaneous electrostatic assembly.

Anionic pollutants in water, especially radioactive iodide, have gained attention because of their adverse toxic side effects on humans. Recently, an exotic biobased amino acid, 4-amino cinnamic ac...

Epidermal growth factor (EGF) accelerates epidermal regeneration, and it is widely studied as a wound-healing agent. However, the special carrier for the topical administration of EGF is urgently needed to deliver EGF on the wound site. In a preceding study, sacran hydrogel film (Sac-HF) showed a possible use as a dressing material for wound healing, as well as a good capability as a drug carrier. In the current study, we prepared Sac-HF containing EGF (Sac/EGF-HF) and then characterized their physicochemical properties, including thickness, swelling ratio, degradability, tensile strength, and morphology. In addition, we have also conducted thermal and crystallography studies using differential scanning calorimetry (DSC) and X-ray diffraction, respectively. Furthermore, we investigated the in vitro influence of Sac/EGF-HF on cell migration using a fibroblast cell line. Morphology study confirmed that the casting method used for the film preparation resulted in a homogeneous film of Sac/EGF-HF. Furthermore, EGF significantly increased the thickness, tensile strength, and degradability of Sac/EGF-HF compared to Sac-HF. Sac/EGF-HF had a lower swelling ability compared to Sac-HF; this result corroborated the tensile strength result. Interestingly, X-ray diffraction and DSC results showed that Sac/EGF-HF had an amorphous shape. The in vitro studies revealed that Sac/EGF-HF induced the fibroblast migration activity. These results conclude that Sac/EGF-HF has the potential properties of HF for biomedical applications.

Bio-based polyureas (PUs) with main-chain furan rings were synthesized by the polyaddition of 2,5-bis(aminomethyl)furan with various diisocyanates, such as methylene diphenyl diisocyanate. Several PU’s were soluble in polar organic solvents, and were cast to form thermomechanically stable films with softening temperatures of over 100 °C. The furan rings of the PU main chains underwent a dynamic Diels-Alder (DA) reaction with bismaleimide (BMI) cross-linkers. While the mixed solution of PU and BMI did not show any apparent signs of reaction at room temperature, the DA reaction proceeded to form gels upon heating to 60 °C, which became a solution again by further heating to 80 °C (retro-DA reaction). The solution phase was maintained by rapid quenching from 80 °C to room temperature, while the gel was reformed upon slow cooling. The recovered gels exhibited self-healing properties. A scratch made by a hot knife at temperatures above 80 °C disappeared spontaneously. When two different gels were cut using a knife at room temperature, placed in contact with each other, and heated to 60 °C, they fused. The ability to control the DA/retro-DA reaction allowed gels of varying composition to heal.