Highly water-resistant paper via infiltration with polymeric microspheres from nanocellulose-stabilized plant oil-derived monomer.

Sustainable strategies to improve the water resistance of cellulose paper are actively sought. In this work, polymeric microspheres (PMs), prepared through emulsion polymerization of cellulose nanofibers stabilized rubber seed oil-derived monomer, were investigated as coatings on corrugated medium paper (CMP). After infiltrating porous paper with PMs, the water-resistant corrugated papers (WRCPn) with enhanced mechanical properties were obtained. When 30 wt% PMs were introduced, WRCP30 turned out to be highly compacted with an increased water contact angle of 106.3° and a low water vapor transmission rate of 81 g/(m2 d) at 23 °C. Meanwhile, the tensile strength of WRCP30 increased to 22.2 MPa, a 4-fold increase from CMP. When tested in a well-hydrated state, 71% of its mechanical strength in the dry state was maintained. Even with a low content of 10 wt% PMs, WRCP10 also exhibited stable tensile strength and water wettability during the cyclic soaking-drying process. Thus, the plant oil based sustainable emulsion polymers provide a convenient route for enhancing the overall performance of cellulose paper.

Association of serum five heavy metals level with all-cause and cause-specific mortality: a large population-based cohort study.

The study aimed to explore the association between five heavy metals exposure (Cadmium, Lead, Mercury, Manganese, and Selenium) and mortality [all-cause, cardiovascular disease (CVD), and cancer-related]. We integrated the data into the National Health and Nutrition Examination Survey from 2011 to 2018 years. A total of 16,092 participants were recruited. The link between heavy metals exposure and mortality was analyzed by constructing a restricted cubic spline (RCS) curve, Cox proportional hazard regression model, and subgroup analysis. The RCS curve was used to show a positive linear relationship between Cadmium, Lead, and all-cause mortality. In contrast, there was a negative linear correlation between Mercury and all-cause mortality. Additionally, Manganese and Selenium also had a J-shaped and L-shaped link with all-cause mortality. The positive linear, positive linear, negative liner, J-shaped, and L-shaped relationships were observed for Cadmium, Lead, Mercury, Manganese, and Selenium and CVD mortality, respectively. Cadmium, Lead, Mercury, and Selenium were observed to exhibit positive linear, U-shaped, negative linear, and L-shaped relationships with cancer-related mortality, respectively. There was an increase and then a decrease in the link between Manganese and cancer-related morality. This study revealed the correlation between the content of different elements and different types of mortality in the U.S. general population.

Chromosome-level genome assembly of the black widow spider Latrodectus elegans illuminates composition and evolution of venom and silk proteins.

BACKGROUND: The black widow spider has both extraordinarily neurotoxic venom and three-dimensional cobwebs composed of diverse types of silk. However, a high-quality reference genome for the black widow spider was still unavailable, which hindered deep understanding and application of the valuable biomass. FINDINGS: We assembled the Latrodectus elegans genome, including a genome size of 1.57 Gb with contig N50 of 4.34 Mb and scaffold N50 of 114.31 Mb. Hi-C scaffolding assigned 98.08% of the genome to 14 pseudo-chromosomes, and with BUSCO, completeness analysis revealed that 98.4% of the core eukaryotic genes were completely present in this genome. Annotation of this genome identified that repetitive sequences account for 506.09 Mb (32.30%) and 20,167 protein-coding genes, and specifically, we identified 55 toxin genes and 26 spidroins and provide preliminary analysis of their composition and evolution. CONCLUSIONS: We present the first chromosome-level genome assembly of a black widow spider and provide substantial toxin and spidroin gene resources. These high-qualified genomic data add valuable resources from a representative spider group and contribute to deep exploration of spider genome evolution, especially in terms of the important issues on the diversification of venom and web-weaving pattern. The sequence data are also firsthand templates for further application of the spider biomass.

Combination of cellulose and plant oil toward sustainable bottlebrush copolymer elastomers with tunable mechanical performance.

In this work, sustainable cellulose-g-poly(lauryl acrylate-co-acrylamide) [Cell-g-P(LA-co-AM)] bottlebrush copolymer elastomers derived from cellulose and plant oil were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. Differential scanning calorimeter (DSC) results indicate that these thermally stable Cell-g-P(LA-co-AM) bottlebrush copolymer elastomers show adjustable melting temperatures. Monotonic and cyclic tensile tests suggest that the mechanical properties, including tensile strength, extensibility, Young's modulus, and elasticity, can be conveniently controlled by changing the LA/AM feed ratio and cellulose content. In such kind of bottlebrush copolymer elastomers, the rigid cellulose backbones act as cross-linking points to provide tensile strength. The incorporated PAM segments can form additional network structure via hydrogen bonding, resulting in enhanced tensile strength but decreased extensibility when more PAM segments are introduced. This versatile strategy can promote the development of sustainable cellulose-based bottlebrush copolymer elastomers from renewable resources.

Cellulose nanocrystal/plant oil polymer composites with hydrophobicity, humidity-sensitivity, and high wet strength.

The preparation of high-performance cellulose nanocrystals (CNCs)/plant oil-derived polymer composites is still a challenge, due to their poor compatibility. Here, by designing amide groups and epoxy groups on sunflower oil derived polymers, appropriate interfacial hydrogen bond interactions between the polymers and CNCs were constructed, where CNCs were homogenously dispersed in polymer matrix. Tensile tests and DMA results revealed that the incorporation of CNCs into sunflower oil derived epoxy polymers significantly enhanced the tensile strength and storage modulus. More importantly, nanocomposites with 50 wt% CNCs are still hydrophobic, which not only show a fast and reversible humidity induced modulus switch, but also exhibit high wet strength (19.9 MPa) after equilibrium water adsorption. The present work revealed that proper designed CNCs/plant oil polymer nanocomposites are good candidates for high performance and functional materials, which are able to replace petroleum-based materials in various fields.

Modulating Morphologies and Surface Properties of Nanoparticles from Cellulose-Grafted Bottlebrush Copolymers Using Complementary Hydrogen-Bonding between Nucleobases.

Herein we report the synthesis of a cellulose-grafted bottlebrush copolymer with nucleobases as hydrophobic moieties. Well-defined spherical micelles from this bottlebrush copolymer were fabricated via a solvent switch method. A morphological transition from spheres to worms was only observed to occur when a diblock copolymer with a complementary nucleobase functionality was introduced. Hydrophobic interaction is not capable of triggering the morphological transformation, and the diblock copolymer with the heterogeneous acrylamide nucleobase monomer can induce the morphological transition at higher A:T molar ratios, which might be caused by the weak H-bonding interaction. This supramolecular "grafting to" method enables the preparation of a series of nanoparticles with similar shapes and dimensions but distinct surface properties such as zeta potentials. Moreover, reversible morphological transitions between worm-like micelles and spheres can be achieved using a reversible collapsing and swelling of a thermoresponsive polymer. This work highlights that a supramolecular "grafting to" approach between complementary nucleobases can be utilized to tune morphologies and surface properties of nanoparticles.

Sustainable Elastomers from Renewable Biomass.

Sustainable elastomers have undergone explosive growth in recent years, partly due to the resurgence of biobased materials prepared from renewable natural resources. However, mounting challenges still prevail: How can the chemical compositions and macromolecular architectures of sustainable polymers be controlled and broadened? How can their processability and recyclability be enabled? How can they compete with petroleum-based counterparts in both cost and performance? Molecular-biomass-derived polymers, such as polymyrcene, polymenthide, and poly(ε-decalactone), have been employed for constructing thermoplastic elastomers (TPEs). Plant oils are widely used for fabricating thermoset elastomers. We use abundant biomass, such as plant oils, cellulose, rosin acids, and lignin, to develop elastomers covering a wide range of structure-property relationships in the hope of delivering better performance. In this Account, recent progress in preparing monomers and TPEs from biomass is first reviewed. ABA triblock copolymer TPEs were obtained with a soft middle block containing a soybean-oil-based monomer and hard outer blocks containing styrene. In addition, a combination of biobased monomers from rosin acids and soybean oil was formulated to prepare triblock copolymer TPEs. Together with the above-mentioned approaches based on block copolymers, multigraft copolymers with a soft backbone and rigid side chains are recognized as the first-generation and second-generation TPEs, respectively. It has been recently demonstrated that multigraft copolymers with a rigid backbone and elastic side chains can also be used as a novel architecture of TPEs. Natural polymers, such as cellulose and lignin, are utilized as a stiff, macromolecular backbone. Cellulose/lignin graft copolymers with side chains containing a copolymer of methyl methacrylate and butyl acrylate exhibited excellent elastic properties. Cellulose graft copolymers with biomass-derived polymers as side chains were further explored to enhance the overall sustainability. Isoprene polymers were grafted from a cellulosic backbone to afford Cell-g-polyisoprene copolymers. Via cross-linking of these graft copolymers, human-skin-mimic elastomers and high resilient elastomers with a well-defined network structure were achieved. The mechanical properties of these resilient elastomers could be finely controlled by tuning the cellulose content. As isoprene can be produced by engineering of microorganisms, these elastomers could be a renewable alternative to petroleum products. In summary, triblock copolymer and graft copolymer TPEs with biomass components, skin-mimic elastomers, high resilient biobased elastomers, and engineering of macromolecular architectures for elastomers are discussed. These approaches and design provide us knowledge on the potential to make sustainable elastomers for various applications to compete with petroleum-based counterparts.

Plant Oil-Derived Epoxy Polymers toward Sustainable Biobased Thermosets.

Epoxy polymers (EPs) derived from soybean oil with varied chemical structures are synthesized. These polymers are then cured with anhydrides to yield soybean-oil-derived epoxy thermosets. The curing kinetic, thermal, and mechanical properties are well characterized. Due to the high epoxide functionality per epoxy polymer chain, these thermosets exhibit tensile strength over an order of magnitude higher than a control formulation with epoxidized soybean oil. More importantly, thermosetting materials ranging from soft elastomers to tough thermosets can be obtained simply by using different EPs and/or by controlling feed ratios of EPs to anhydrides.

A biomass approach to mendable bio-elastomers.

Sustainable bioelastomers with high elastic recovery, high resilience and mendability are conceptualized with low chain-entanglement polymers that are predominantly originated from renewable biomass. Polymers with plant oil-derived fatty groups at the side chain were installed with furan, which allowed Diels-Alder addition to introduce dynamic covalent crosslinking. These elastomers are mendable via retro Diels-Alder. Reprocessing of these polymers led to the formation of elastomers with preservation of excellent resilience and elastic recovery.

Biomass Approach toward Robust, Sustainable, Multiple-Shape-Memory Materials.

We report biomass-derived, shape-memory materials prepared via simple reactions, including "grafting from" ATRP and TAD click chemistry. Although the biomass, including plant oils and cellulose nanocrystals, has heterogeneous chemical structures in nature, these materials exhibit excellent multiple shape-memory properties toward temperature, water, and organic solvents, which are comparable to petroleum counterparts. The work presented herein provides burgeoning opportunities to design the next-generation, low-cost, biomass-prevalent, green materials for niche applications.