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Cellulose, a linear polysaccharide biopolymer, has applications in various industries including food packaging, personal care products, and construction, due to its unique physico-chemical properties, as well as its biocompatibility and [...]

A range of cross-linkable latex copolymers with biobased content of up to 90% was synthesized from isobornyl methacrylate combined with acrylic monomers based on high-oleic soybean oil (HO-SBM) or camelina oil (CMM) through miniemulsion polymerization. By varying the HO-SBM and CMM macromolecular fractions, the cross-linking density of the resulting materials can be altered due to differences in the fatty acid profiles of the plant-oil-based monomers. The glass transition temperature of the synthesized copolymers correlates very well with the calculated Flory–Fox values. A higher cross-linking density of the biobased copolymer films leads to a notable growth in the modulus of the materials, while the elongation at break decreases due to more restricted macromolecular mobility. Remarkably, the copolymer with the highest unsaturation degree in the investigated range (based on CMM) shows an increase in both the modulus and elongation at break, due perhaps to extended entanglements of fatty-acid-based side chains. The adhesion performance of the cross-linked biobased copolymers was evaluated by performing shear and peel strength measurements on steel and polypropylene. Based on the obtained results, the unsaturation degree of CMM and HO-SBM (determined by plant oil composition) can be applied as a criterion for adjusting adhesion by choosing plant-oil-based monomers (or their mixtures) with different unsaturation degrees to achieve properties and performance required for specific applications.

Extracting, stabilizing, or delivering biomacromolecules such as proteins and peptides in organic phases have potential applications in biocatalysis, protein extraction, and food antioxidation. However, most current delivery/stabilization platforms face various limitations such as protein/peptide molecular size, platform stability/reusability, and/or potential damage to the cargos. A potential solution to these problems is micellar self-assemblies from amphiphilic invertible polymers, which have recently been demonstrated to be powerful as molecular hosts to deliver both small molecular drugs and functional polypeptides in the aqueous phase. To better understand the function of biomacromolecules and predict the usefulness of the formed invertible micellar assemblies (IMAs) as biomacromolecular hosts in organic phases, it is critical to characterize the spatial distribution, structure, and dynamics of biomacromolecules in the IMA including those upon release. However, the background signals of the IMAs limit the application of most peptide characterization approaches. In this work, we overcome the technical barriers by using site-directed spin labeling electron paramagnetic resonance to probe the spatial arrangement and release of a model, the hemagglutinin (HA) peptide, in the IMAs formed from two different amphiphilic invertible polymers. By site-specifically probing three residues along the peptide chain, for the first time, we depict the possible spatial distribution of HA within the IMAs. By triggering the disassembly of the IMAs with a thermodynamically good solvent (in this study, acetone), we detailed the stability of IMAs in toluene and the peptide release conditions once the polarity of the medium changes. Our findings are important for the application of peptides/proteins at the polar–nonpolar interface or using this interface to extract or deliver biomacromolecules. Our work also demonstrates the power of SDSL-EPR on probing peptide or micelle dynamics, which can be generalized to understand proteins or other biomacromolecules in micellar polymer assemblies in varied applications.

As the concentration of amphiphilic invertible polymers (AIPs) in both polar and nonpolar solvents increases, the AIP macromolecules self-assemble into polymeric micelles. The resulting invertible micellar assemblies (IMAs) have a controlled size and morphology determined by macromolecular composition and hydrophilic lipophilic balance (HLB) of the AIPs. It has been demonstrated that AIPs can rapidly switch the conformation in response to changes in the environmental polarity, thus facilitating, micellar inversion. In combination with IMAs’ ability to solubilize otherwise insoluble substances, inversion can be promising for rapid and controlled cargo delivery and release in applications that require simultaneous utility in polar and nonpolar media. While IMAs have been demonstrated to interact with peptides, fundamental pictures of micellar inversionremain elusive and became the focus of this work, including the behavior of the incorporated peptide in IMAs at the molecular level at different polarities of the environment and how polymer composition impacts such behavior. To trigger conformational changes of the micelle-forming AIPs, acetone (no self-assembly occurs in acetone) was added into the peptide-loaded IMAs aqueous solutions. Electron Paramagnetic Resonance (EPR) in combination with peptide spin labeling was used to probe the local environment of an antigenic peptide at various acetone concentrations. The obtained results are consistent with the previously revealed micellar structure. Increasing acetone percentage clearly impacts the extent of IMA inversion as reported by the labeled peptide and quantified by semiquantitative spectral analysis. The conformational changes are different for the two AIPs differing in the macromolecular composition. Conformational changes clearly relate to the HLB of the AIPs macromolecules and can certainly be meaningful in controlling the IMAs-mediated peptide release.

Sucrose octasoyate (SS8) was investigated as a reactive diluent for a medium oil alkyd (MOA). SS8, which is derived from sugar and soybean oil, is 100% biobased, nontoxic, and biodegradable. As a result of its unique molecular architecture, it was expected that SS8 would be an excellent reactive diluent for alkyd coatings. The experiment conducted basically involved the incremental replacement of the MOA with SS8, while maintaining essentially equivalent solution viscosity. The properties of cured coatings were determined using industry standard methods. In general, it was found that SS8 could be used to reduce volatile organic compound content of the coatings, while also reducing drying time (i.e., tack-free time), increasing solvent resistance, and increasing impact resistance. Of the properties measured, the only cured film property that was negatively affected by the use of SS8 was the König pendulum hardness. However, the reduction in König pendulum hardness was only observed when the amount of MOA replaced by SS8 was greater than 10 wt%. Overall, these initial results suggest that SS8 is a very good reactive diluent for alkyd coatings.

Summary:Peroxide‐containing chitosan was synthesized using a polymer‐analogous reaction between chitosan and tert‐butylperoxymethyl ester of maleic acid. Peroxide‐containing chitosan macromolecules cross‐link into a polymeric hydrogel network in the presence of 1‐vinyl‐2‐pyrrolidone upon heating. Polymeric hydrogels are formed due to reactions of radical chain transfer and recombination. Reacting radical species are chitosan macroradicals and poly(vinylpyrrolidone) macroradicals formed by decomposition of peroxide‐containing fragments. Synthesized hydrogels are pH‐responsive and facilitate drug release.

Summary:Results of a study on polymer surface modification using heterofunctional polyperoxides are presented. A prognostic model of the polymer surface modifier efficiency was developed on the basis of obtained data. It was shown that implementation of demands to the macromolecule composition during development of new peroxide‐containing modifiers in combination with sufficient peroxide group reactivity increased efficiency of the polymer surface modification.

Summary:Novel amphiphilic comb‐like poly(α‐olefin‐co‐maleic anhydride) with a controlled ratio of hydrophilic (polyoxyethylene) and hydrophobic (polymethylene) side chains have been synthesized and characterized. The comb‐like copolymers are soluble in organic and aqueous media and form micelles whose behaviour could be correlated to the chemical structure of polymers. We foresee that amphiphilic properties of the novel comb‐like polymers are obviously the basis of new architectures in solution which could be used in a broad range of applications. Using micelles from these copolymers, silver nanoparticles with a narrow particle size distribution have been obtained as stable dispersion in both polar and non‐polar media.

In this study, highly stable gold and silver nanoparticles evenly distributed within a crosslinked poly(acrylamide)/poly(N‐(hydroxymethyl)acrylamide) (PAAm‐PHMAAm) network have been fabricated without addition of a reducing agent. Remarkably, the same chemical hydrogel composition has been involved in the successful fabrication of spherical gold and silver nanoparticles within the hydrogel template. The hydrogel network acts simultaneously as an efficient reducing agent and stabilizer. The PAAm–PHMAAm hydrogel network binds metal ions and, following reduction of bound to crosslinked template metal ions, proceeds via oxidation of hydroxymethyl hydrogel fragments. A one‐electron mechanism is proposed for the formation of the silver and gold nanoparticles.

Plant-based proteins are attractive components which may serve as sustainable alternatives to current petrochemical products. Both soy protein and major corn protein, zein, are of interest in food packaging applications due to their sustainability, biodegradation properties, and inherent physicochemical properties. This study discusses the development of bioplastic materials, where it explores the effects of combining zein, soy protein, and plasticizing latexes derived from plant oil-based monomers (POBMs) on properties of resulting bioplastic films. By looking for synergistic effects of soy protein’s inherent film formation ability and zein’s higher strength, we prepare strong yet flexible soy–zein films as materials, called proteoposites. Incorporation of natural additive POBM-latexes helps to plasticize and hydrophobize the bioplastic films and thus to improve mechanical and barrier properties. Variation of the POBM-latexes’ particle size further aims to enhance the performance of resulting bioplastic films. As a result, modified soy–zein proteoposite films with improved moisture resistance, enhanced mechanical behavior, and greater barrier properties were developed. Machine learning-based computational models were utilized in order to find main structural factors affecting the bioplastic’s properties and develop a quantitative structure–property relationship model between the physicochemical properties of the film components and the resulted bioplastics’ properties and performance. The developed model effectively predicts experimental outcomes with >85% (R2: 0.85) accuracy. The newly synthesized proteoposites confirmed the machine learning model predictions. As a result, proteoposite films made of two plant proteins and modified with POBM-latexes can be considered as an attractive and viable replacement for petrochemical food packaging products.

Gold colloidal particles were synthesized and modified by molecular self‐assembly. In addition, the reaction of biotinylated colloids with a tetrameric protein, avidin, was studied by optical absorption spectroscopy and dynamic light scattering. The modification involves the chemisorption of octadecanethiol on the gold, with the further attachment of alkyl biotin and cross‐linking with avidin molecules. The specific interaction of avidin with biotin leads to the controlled cross‐linking of particles. The degree of flocculation was quantified using a semi‐empirical flocculation parameter and its dependence on the biotinylation system was studied. The measured data were in good agreement, showing the possibility of regulating the aggregation rate and size of the aggregates using the experimental time, degree of biotinylation, and avidin concentration. The morphology of the self‐assembled gold monolayers, from the aggregated particles, was imaged by high‐resolution scanning electron microscopy. The structure of the thin particulate film depends on the bulk aggregate size and aggregation rate.

We synthesized and characterized novel amphiphilic polyesters with both hydrophilic and hydrophobic functionalities. The polyesters are soluble in organic and aqueous media and reveal the formation of inverse architectures whose behavior could be correlated to their chemical structure. We foresee that the amphiphilic properties of the polyesters reported here are obviously the basis of new architectures both in solution and on the solid surfaces, which could be used in a broad range of applications. The described synthesis of the copolymers is very simple and is based on commercially available products. That makes this approach attractive in various uses.

Oscillations of the aggregate sizes of SiO2 particles covered by an adsorbed layer of poly(vinylpyridine) (PVP) at pH 3 with a periodicity of about 15 h were observed using a particle counting technique. The same oscillation was found for the contact angle values of water on the surface of Si wafers (with top silica layer) covered by adsorbed PVP as a function of exposure time in a PVP water solution.