Synthesis of divanillic acid-based aromatic polyamides with linear and branched side-chains and the effect of side-chain structure on thermal and mechanical properties

Divanillic acid (DVA)-based aromatic polyamides (PAs) consisting of DVA with linear (methyl, butyl, hexyl, and octyl groups) or branched (isopropyl and isobutyl groups) side chains and 4,4'-methyldianillin were synthesized as high-performance and ultra-high-performance biomass plastics. The DVA PAs were amorphous with high thermal stability (decomposition temperature of ca. 380 °C). The glass transition temperature (Tg) of the DVA PAs depended on the side-chain composition in a linear manner, indicating the PA main chain possessed a random structure. The polymers were pressed to form melt-pressed films. The DVA PAs with a higher content of shorter side chains exhibited both higher Tg and tensile strength than those of polymers with a lower content of shorter side chains. The PAs exhibited Tg in the range of ca. 150-253 °C. The branched PA with isopropyl side chains exhibited the highest Tg of 253 °C and highest tensile strength of 63 MPa among the DVA PAs. The PAs with isopropyl side chains and some linear side chains (methyl/hexyl combination) exhibited high tensile strength of approximately 60-70 MPa; however, their Tg varied from 170 to 253 °C. The branched PA exhibited the highest Tg, tensile strength, and Young's modulus of the polymers. The thermal stability and mechanical properties of the PAs were tuned by their side-chain structure and composition.

Melt Polycondensation Strategy for Amide-Functionalized l-Aspartic Acid Amphiphilic Polyester Nano-assemblies and Enzyme-Responsive Drug Delivery in Cancer Cells

Aliphatic polyesters are intrinsically enzymatic-biodegradable, and there is ever-increasing demand for safe and smart next-generation biomaterials including drug delivery nano-vectors in cancer research. Using bioresource-based biodegradable polyesters is one of the elegant strategies to meet this requirement; here, we report an l-amino acid-based amide-functionalized polyester platform and explore their lysosomal enzymatic biodegradation aspects to administrate anticancer drugs in cancer cells. l-Aspartic acid was chosen and different amide-side chain-functionalized di-ester monomers were tailor-made having aromatic, aliphatic, and bio-source pendant units. Under solvent-free melt polycondensation methodology; these monomers underwent polymerization to yield high molecular weight polyesters with tunable thermal properties. PEGylated l-aspartic monomer was designed to make thermo-responsive amphiphilic polyesters. This amphiphilic polyester was self-assembled into a 140 ± 10 nm-sized spherical nanoparticle in aqueous medium, which exhibited lower critical solution temperature at 40-42 °C. The polyester nano-assemblies showed excellent encapsulation capabilities for anticancer drug doxorubicin (DOX), anti-inflammatory drug curcumin, biomarkers such as rose bengal (RB), and 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt. The amphiphilic polyester NP was found to be very stable under extracellular conditions and underwent degradation upon exposure to horse liver esterase enzyme in phosphate-buffered saline at 37 °C to release 90% of the loaded cargoes. Cytotoxicity studies in breast cancer MCF 7 and wild-type mouse embryonic fibroblasts cell lines revealed that the amphiphilic polyester was non-toxic to cell lines up to 100 μg/mL, while their drug-loaded polyester nanoparticles were able to inhibit the cancerous cell growth. Temperature-dependent cellular uptake studies further confirmed the energy-dependent endocytosis of polymer NPs across the cellular membranes. Confocal laser scanning microscopy assisted time-dependent cellular uptake analysis directly evident for the endocytosis of DOX loaded polymer NP and their internalization for biodegradation. In a nutshell, the present investigation opens up an avenue for the l-amino acid-based biodegradable polyesters from l-aspartic acids, and the proof of concept is demonstrated for drug delivery in the cancer cell line.

All-Atom Molecular Dynamics Simulations on a Single Chain of PET and PEV Polymers

Polyethylene vanillic (PEV), a bio-based material, has mechanical and thermal properties similar to polyethylene terephthalate (PET), the most common polymer used in industries. The present study aimed to investigate and compare their structural dynamics and physical data using a computational approach. The simple model of a single-chain polymer containing 100 repeating units was performed by all-atom molecular dynamics (MD) simulations with refined OPLS–AA force field parameters. As a result, the flexibility of the PEV structure was greater than that of PET. PET and PEV polymers had the predicted glass transition temperature T_g values of approximately 345 K and 353 K, respectively. PEV showed a slightly higher T_g than PET, consistent with current experimental evidence.

Downstream processing of lignin derived feedstock into end products

This review provides critical analysis on various downstream processes to convert lignin derived feedstock into fuels, chemicals and materials.

Synthesis, Thermal Properties and Decomposition Mechanism of Poly(Ethylene Vanillate) Polyester

Plastics are perceived as modern and versatile materials, but their use is linked to numerous environmental issues as their production is based on finite raw materials (petroleum or natural gas). Additionally, their low biodegradability results in the accumulation of microplastics. As a result, there is extensive interest in the production of new, environmentally friendly, bio-based and biodegradable polymers. In this context, poly(ethylene vanillate) (PEV) has a great potential as a potentially bio-based alternative to poly(ethylene terephthalate); however, it has not yet been extensively studied. In the present work, the preparation of PEV is reported. The enthalpy and the entropy of fusion of the pure crystalline PEV have been estimated for the first time. Additionally, the equilibrium melting temperature has also been calculated. Furthermore, the isothermal and non-isothermal crystallization behavior are reported in detail, and new insights on the thermal stability and degradation mechanism of PEV are given.

Structure/property relationships in copolymers comprising renewable isosorbide, glucarodilactone, and 2,5-bis(hydroxymethyl)furan subunits

Carbohydrates and their derivatives have great potential as building blocks for the development of renewable materials that are cost and performance competitive with conventional petroleum-based materials.

Crosslinkable polyesters based on monomers derived from renewable lignin

Crosslinked polyesters based on renewable resources have been successfully prepared, they have better tensile property and biodegradability.

Experimental solubilities of two lipid derivatives in supercritical carbon dioxide and new correlations based on activity coefficient models

Solubilities of 10-undecen-1-ol and geranyl butyrate were determined and correlated based on new models by combinations of solution/association theories.

Synthesis and properties of polyesters derived from renewable eugenol and α,ω-diols via a continuous overheating method

Two series of thermoplastic polyesters derived from renewable eugenol and linear aliphatic α,ω-diols were prepared. The dependence of the properties on the α,ω-diol length was investigated.

Synthesis and properties of temperature-sensitive and chemically crosslinkable poly(ether-urethane) hydrogel

The PEU-MA solutions can gelate at physiological temperature, and be further crosslinked by UV light.

Polyesters derived from bio-based eugenol and 10-undecenoic acid: synthesis, characterization, and structure–property relationships

A series of thermoplastic polyesters with versatile thermal and mechanical properties were prepared from renewable eugenol, which is extracted from lignocellulosic biomass-clove oil.

Renewable (semi)aromatic polyesters from symmetrical vanillin-based dimers

Two symmetrical biphenyl monomers derived from vanillin, a methylated divanillyl diol and a methylated dimethylvanillate dimer, were synthesized and employed as (co)monomers for the design of renewable (semi)aromatic polyesters.

Novel vanillic acid-based poly(ether–ester)s: from synthesis to properties

Two series of bio-based poly(ether–ester)s prepared from vanillic acid and linear α,ω-diols have been successfully synthesized by the direct esterification method. The mechanical properties of these poly(ether–ester)s are excellent, making them suitable materials for some practical applications.

Facile and Highly Efficient Strategy for Synthesis of Functional Polyesters via Tetramethyl Guanidine Promoted Polyesterification at Room Temperature

A facile and highly efficient strategy for the synthesis of functional polyesters from 10-undecenoic acid, which is abundantly available and derived from ricin oil, has been successfully achieved using 1,1,3,3-tetramethyl guanidine (TMG) as a promoter at room temperature. The experimental results indicate that high molecular weight polyesters have been obtained and a variety of functional groups, such as alkenyl, alkynyl, nitro, epoxy, hydroxyl, and bromoisobutyrate, can be incorporated as pendant groups. The structures of the obtained polymers were demonstrated by ¹H and ¹³C NMR spectroscopy and their thermal properties were studied by DSC and TGA.

Biobased building blocks for the rational design of renewable block polymers

Block polymers (BPs) derived from biomass (biobased) are necessary components of a sustainable future that relies minimally on petroleum-based plastics for applications ranging from thermoplastic elastomers and pressure-sensitive adhesives to blend compatibilizers. To facilitate their adoption, renewable BPs must be affordable, durable, processable, versatile, and reasonably benign. Their desirability further depends on the relative sustainability of the renewable resources and the methods employed in the monomer and polymer syntheses. Various strategies allow these BPs' characteristics to be tuned and enhanced for commercial applications, and many of these techniques also can be applied to manipulate the wide-ranging mechanical and thermal properties of biobased and self-assembling block polymers. From feedstock to application, this review article highlights promising renewable BPs, plus their material and assembly properties, in support of de novo design strategies that could revolutionize material sustainability.