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A variety of renewable starting materials, such as sugars and polysaccharides, vegetable oils, lignin, pine resin derivatives, and proteins, have so far been investigated for the preparation of bio-based polymers. Among the various sources of bio-based feedstock, vegetable oils are one of the most widely used starting materials in the polymer industry due to their easy availability, low toxicity, and relative low cost. Another bio-based plastic of great interest is poly(lactic acid) (PLA), widely used in multiple commercial applications nowadays. There is an intrinsic expectation that bio-based polymers are also biodegradable, but in reality there is no guarantee that polymers prepared from biorenewable feedstock exhibit significant or relevant biodegradability. Biodegradability studies are therefore crucial in order to assess the long-term environmental impact of such materials. This review presents a brief overview of the different classes of bio-based polymers, with a strong focus on vegetable oil-derived resins and PLA. An entire section is dedicated to a discussion of the literature addressing the biodegradability of bio-based polymers.

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This review focuses on the progress made over the last decade, in the development of bio-based matrices for biocomposite applications.

Catalyst deactivation resulting from the hydrothermal leaching of sulfonic acid residues and the deposition of carbonaceous residues was studied using condensed phase flow reactor experiments along with state-of-the-art solid-state NMR. Several commercially available sulfonic acid-containing heterogeneous Bronsted acids were compared by measuring the rates of sulfonic acid breakdown at hydrothermal flow conditions of 160 degrees C. Amberlyst 45 was found to show higher hydrothermal stability when compared to both Nafion and Amberlyst 15, with <10% loss in acidity after 48 h. The dehydration reaction of fructose to hydroxymethylfurfural (HMF) was used as a model system to compare deactivation rates from carbon deposition (fouling) to those from sulfur leaching, and deactivation from fouling was shown to be dramatically faster than that from sulfonic acid leaching alone. Fouling rates were then investigated in greater detail by comparing the influence of several factors including reactant, solvent, residence time, and feed concentration. The only successful approach to minimize fouling was the use of a polar aprotic solvent [dimethyl sulfoxide (DMSO)] with dilute (50 mM) reactant streams. In aqueous systems, operating the reactor in a regime with low conversion conditions (short residence times) does not significantly improve the longevity of the catalyst. Spent catalysts were characterized using C-13 solid-state NMR spectroscopy enhanced by dynamic nuclear polarization. Additionally, in situ H-1 and C-13 high-resolution magic angle spinning (HR-MAS) solid-state NMR spectroscopies were used to investigate the solvent influence at the catalyst interface. The HR-MAS NMR studies showed that in polar aprotic solvents, the increased acidity leads to greater selectivity toward HMF; more importantly, that the dehydration products do not readily adhere to the surface in DMSO, in contrast to their behavior in water. The results demonstrate that more active and longer-lived acid catalysts could be obtained by tuning the solvent and surface polarity to allow for efficient desorption of products, thereby reducing the catalyst deactivation that occurs due to fouling.

Patchiness or spatial variability is ubiquitous in marine systems. With increasing anthropogenic impacts to coastal resources and coastal systems being disproportionately large contributors to ocean productivity, identifying the spatial scales of this patchiness, particularly in coastal waters, is of critical importance to understand coastal ecosystem dynamics. The current work focuses on fine scale structure in three coastal regions. More specifically, we utilize variogram analyses to identify sub-kilometer scales of variability in biological and physical parameters measured by an autonomous underwater vehicle (AUV) in the Mid-Atlantic Bight, Monterey Bay, and in San Luis Obispo Bay between 2001 and 2004. Critical scales of variability in density, turbidity, fluorescence, and bioluminescence are examined as a function of depth and distance offshore. Furthermore, the effects of undersampling are assessed using predictive error analysis. Results indicate the presence of scales of variability ranging from 10s to 100s of meters and provide valuable insight for sampling design and resource allocation for future studies.

A novel, bio‐based, aromatic monomer (methacrylated vanillyl alcohol, MVA) is synthesized using vanillyl alcohol and methacrylic anhydride in the absence of solvents. The resulting MVA is used as a sustainable comonomer to replace styrene in a maleinated acrylated epoxidized soybean‐oil (MAESO) resin to produce novel thermosets via free radical polymerization. The influence of MVA loading on the viscosity, gelation time, curing extent, thermomechanical properties, and tensile properties of the MAESO–MVA thermoset is investigated. The synthesized MVA exhibits very low volatility, which is beneficial for the development of construction material with low or zero emission. The viscosity of the MAESO–MVA system can be tailored to meet the commercial requirements. Increasing the MVA content accelerates the crosslinking reaction rate and improves thermal and mechanical properties of the MAESO–MVA system. The glass transition temperature increases with increasing MVA content. Soxhlet extraction experiments show that more than 90% of the components are incorporated into the crosslinking network. Overall, the developed MVA monomer shows promising properties to be used as an effective, green comonomer to replace styrene.

Soybean‐oil‐based cationic polyurethane coatings with antibacterial properties have been prepared with a range of different molar ratios of hydroxyl groups from an amine diol. A second series of polyurethane coatings were prepared from soy polyols with different hydroxyl numbers. All of the cationic PU dispersions and films exhibit inhibitory activity against three foodborne pathogens: Salmonella enterica ssp. enterica ser. Typhimurium, Listeria monocytogenes, and Staphylococcus aureus. It is generally observed that increases in the ratio of ammonium cations improve the antibacterial performance. Reduction of the crosslink density by decreasing the hydroxyl number of the soy polyol also results in slightly improved antibacterial properties. Higher glass transition temperatures and improved mechanical properties are observed with corresponding increases in the molar ratios of the amine diol and the diisocyanate. These results show that the mechanical properties of these coatings can be tuned, while maintaining good antibacterial activity.