Development of novel phosphorus-containing epoxy resins from renewable resources

Low-dose exposure to PBDE disrupts genomic integrity and innate immunity in mammary tissue

The low-dose mixture hypothesis of carcinogenesis proposes that exposure to an environmental chemical that is not individually oncogenic may nonetheless be capable of enabling carcinogenesis when it acts in concert with other factors. A class of ubiquitous environmental chemicals that are hypothesized to potentially function in this low-dose capacity are synthesized polybrominated diphenyl ethers (PBDEs). PBDEs can affect correlates of carcinogenesis that include genomic instability and inflammation. However, the effect of low-dose PBDE exposure on such correlates in mammary tissue has not been examined. In the present study, low-dose long-term (16 weeks) administration of PBDE to mice modulated transcriptomic indicators of genomic integrity and innate immunity in normal mammary tissue. PBDE increased transcriptome signatures for the Nuclear Factor Erythroid 2 Like 2 (NFE2L2) response to oxidative stress and decreased signatures for non-homologous end joining DNA repair (NHEJ). PBDE also decreased transcriptome signatures for the cyclic GMP-AMP Synthase - Stimulator of Interferon Genes (cGAS-STING) response, decreased indication of Interferon Stimulated Gene Factor 3 (ISGF3) and Nuclear Factor Kappa B (NF-κB) transcription factor activity, and increased digital cytometry estimates of immature dendritic cells (DCs) in mammary tissue. Replication of the PBDE exposure protocol in mice susceptible to mammary carcinogenesis resulted in greater tumor development. The results support the notion that ongoing exposure to low levels of PBDE can disrupt facets of genomic integrity and innate immunity in mammary tissue. Such effects affirm that synthesized PBDEs are a class of environmental chemicals that reasonably fit the low-dose mixture hypothesis.

Synthesis of non-phosphorylated epoxidised corn oil as a novel green flame retardant thermoset resin

This study aimed to produce a new potential flame retardant thermoset resin from epoxidised corn oil through a one-pot method using liquid inorganic catalysed with hydrogen peroxide. Using a gas chromatography-mass selective detector, attenuated total reflectance-fourier transform infrared spectroscopy, proton nuclear magnetic resonance imaging, optical microscopy, and scanning emission microscopy, we synthesised a bio-based resin based on newly designed parameters. The flame retardant capacity was fully established using thermogravimetric analysis and a micro calorimeter. The produced epoxidised corn oil had a relative percentage conversion of oxirane of approximately 91.70%, wherein the amount of double bonds converted into epoxides was calculated. A significant reduction from 17 to 40% in peak heat rate release (pHRR) and 26-30% in total heat release was observed, confirming its flame retardant property. Thus, the potential of epoxidised corn oil was demonstrated.

Oil-Based Polymer Coatings on CAN Fertilizer in Oilseed Rape (Brassica napus L.) Nutrition

Fertilizer coating can increase the efficiency of N fertilizers and reduce their negative impact on the environment. This may be achieved by the utilization of biodegradable natural coating materials instead of polyurethane-based polymers. The aim of this study was to detect the effect of calcium ammonium nitrate (CAN) fertilizer coated with modified conventional polyurethane enhanced with vegetable oils on the yield and quality of Brassica napus L. compared to CAN fertilizer with a vegetable oil-based polymer and to assess the risks of nitrogen loss. Three types of treatments were tested for both coated fertilizers: divided application (CAN, coated CAN), a single application of coated CAN, and a single application of CAN with coated CAN (1:2). A single application of coated CAN with both types of coating in the growth stage of the 9th true leaf significantly increased the yield, the thousand seed weight, and oil production compared to the uncoated CAN. The potential of using coated CAN may be seen in a slow nitrogen release ensuring the nitrogen demand for rapeseed plants throughout vegetation and eliminating the risk of its loss. The increased potential of NH4+ volatilization and NO3- leaching were determined using the uncoated CAN fertilizer compared to the coated variants. Oil-based polymer coatings on CAN fertilizer can be considered as an adequate replacement for partially modified conventional polyurethane.

Plant oil-based polymers

Polymer materials derived from natural resources have gained increasing attention in recent years because of the uncertainties concerning petroleum supply and prices in the future as well as their environmental pollution problems. As one of the most abundant renewable resources, plant oils are suitable starting materials for polymers because of their low cost, the rich chemistry that their triglyceride structure provides, and their potential biodegradability. This chapter covers the structure, modification of triglycerides and their derivatives as well as synthesis of polymers therefrom. The remarkable advances during the last two decades in organic synthesis using plant oils and the basic oleochemicals derived from them are selectively reported and updated. Various methods, such as condensation, radical/cationic polymerization, metathesis procedure, and living polymerization, have also been applied in constructing oil-based polymers. Based on the advance of these changes, traditional polymers such as polyamides, polyesters, and epoxy resins have been renewed. Partial oil-based polymers have already been applied in some industrial areas and recent developments in this field offer promising new opportunities.

Biodegradable Polymer Coated Granular Urea Slows Down N Release Kinetics and Improves Spinach Productivity

Low nitrogen (N) utilization efficiency due to environmental N losses from fertilizers results in high-cost on-farm production. Urea coating with biodegradable polymers can prevent these losses by controlling the N release of fertilizers. We calculated N release kinetics of coated granular with various biodegradable polymeric materials and its impact on spinach yield and N uptake. Different formulations were used, (i) G-1: 10% starch + 5% polyvinyl alcohol (PVA) + 5% molasses; (ii) G-2: 10% starch + 5% PVA + 5% paraffin wax (PW); (iii) G-3: 5% gelatin + 10% gum arabic + 5% PW; (iv) G-4: 5% molasses + 5% gelatin + 10% gum arabic, to coat urea using a fluidized bed coater. The morphological and X-ray diffraction (XRD) analyses indicated that a uniform coating layer with no new phase formation occurred. In the G-2 treatment, maximum crushing strength (72.9 N) was achieved with a slowed-down N release rate and increased efficiency of 31%. This resulted in increased spinach dry foliage yield (47%), N uptake (60%) and apparent N recovery (ANR: 130%) from G-2 compared to uncoated urea (G-0). Therefore, coating granular urea with biodegradable polymers is a good choice to slower down the N release rate and enhances the crop yield and N utilization efficiency from urea.

Novel sustainable biobased flame retardant from functionalized vegetable oil for enhanced flame retardancy of engineering plastic

The flame retardancy of an engineering plastic, poly(butylene terephthalate) (PBT), with a biobased flame retardant (FR) made from phosphorylated linseed oil (PLO) and phosphorylated downstream corn oil (PCO) was studied. Different phosphorus moieties were incorporated into the vegetable oil backbone through a ring-opening reaction. The chemical structure of the phosphorylated oil was confirmed by Fourier-transform infrared (FTIR) and nuclear resonance magnetic (NMR) spectroscopy. It was found that the incorporation of only 7.5 wt% of PLO was sufficient to change the UL-94 fire class of PBT from non-rating to V-0. The flame-retardancy mechanism of the PBT/PLO blends was evaluated from TGA-FTIR analysis. The combined effects of the gas phase mechanism and the dripping tendency of the blends aided to retard the flame propagation effectively. As the synthesized PLO and PCO contained high free fatty acids, the acid-ester exchange reaction occurred in the blends to form oligomers during the ignition. As a result, the blend dripped immediately and the drips carried all the heat to prevent fire. This work suggests that this sustainable biobased FR could be a desirable alternative to halogen-based FRs for PBT and other engineering polymers to develop more environmentally friendly FR products for various future applications.

Phosphorus-Containing Flame Retardants from Biobased Chemicals and Their Application in Polyesters and Epoxy Resins

Phosphorus-containing flame retardants synthesized from renewable resources have had a lot of impact in recent years. This article outlines the synthesis, characterization and evaluation of these compounds in polyesters and epoxy resins. The different approaches used in producing biobased flame retardant polyesters and epoxy resins are reported. While for the polyesters biomass derived compounds usually are phosphorylated and melt blended with the polymer, biobased flame retardants for epoxy resins are directly incorporated into the polymer structure by a using a phosphorylated biobased monomer or curing agent. Evaluating the efficiency of the flame retardant composites is done by discussing results obtained from UL94 vertical burning, limiting oxygen index (LOI) and cone calorimetry tests. The review ends with an outlook on future development trends of biobased flame retardant systems for polyesters and epoxy resins.

Bio-based epoxy-anhydride thermosets from six-armed linoleic acid-derived epoxy resin

A series of bio-based epoxy-anhydride thermosets with considerably high thermal and mechanical properties were developed from 4-methyl hexahydrophthalic anhydride and six-armed linoleic-acid-derived epoxy resin.

From a bio-based phosphorus-containing epoxy monomer to fully bio-based flame-retardant thermosets

In this work, phloroglucinol was used as a renewable resource to prepare an epoxy monomer and phosphorus containing reactive flame retardant (FR).

Synthesis of biobased phosphate flame retardants

An approach to prepare some biobased flame retardant (FR) compounds is presented. The adopted strategy consists in functionalizing an aromatic biobased phenolic compound, the phloroglucinol, with different phosphate groups in order to promote a charring effect. Different chlorophosphates were grafted onto phloroglucinol hydroxy groups and the functionalization of the hydroxy groups was quantitative. The synthesized biobased FR were incorporated into an epoxy matrix as additive to estimate their flame retardant properties. The influence of different parameters was studied such as the phosphorus content of the thermoset or the nature of the R group of the used phosphate P-O-R. MEB/EDX observations proved the influence of this R group on the compatibility between the FR and the matrix and its importance to obtain homogeneous thermoset. Thermogravimetric analyses of the phosphorus-containing thermosets showed a small decrease in thermal stability accompanied by a char yield almost tripled for a 3 %wP-containing thermoset compared to that of the thermoset without any FR. Pyrolysis combustion flow calorimetry was also used to evaluate the flammability of the modified epoxy thermoset. A significant decrease in peak of heat release rate and total heat released was observed compared to thermoset without FR. These results demonstrate the good flame retardant properties of these biobased phosphates in an epoxy matrix. In addition these results show the potential of the biobased phenolic compounds as raw material for flame retardants syntheses.

Synthesis and spectral characterization of methyl 9(10)-dialkylphosphonostearates

Dimethyl, diethyl, and di-n-butyl phosphites were reacted with methyl or ethyl oleates using thermally initiated radical reactions. Reactions were conducted with or without the presence of a dilauroyl peroxide initiator. The reactions gave mixture of isomers with the phosphorus attached at the 9 or 10 carbon of the stearates. High yields (94-97%) and high purity products (98-99% by GC) were obtained in the presence of the initiator, while without initiator, the reaction was very slow resulting in very low conversions (<50% after 6 days). The phosphonostearate products were positively identified and thoroughly characterized using GC with EI-MS, FTIR, and (1)H-, (13)C-, and (31)P NMR spectra. GC achieved only partial resolution of the positional isomers. Principal component analysis was applied to successfully separate the MS-EI spectra of fractions from the 9- and 10-isomers. A mechanism to explain the observed MS fragmentation pattern and the relative abundances is proposed. 2D-NMR data analysis was applied to assign values of (13)C- and (1)H NMR shifts as well as P-C and P-H splitting constants. The molecular volume and the refractive indices of the phosphonostearates were determined experimentally and were found to be in agreement with the computationally predicted values using the PM3 semi-empirical method and the group-contribution method of Bondi.

Recent advances in vegetable oil-based polyurethanes

Polyurethanes are among the most versatile polymers because of the wide range of monomers, particularly diols or polyols, that can be utilized in their synthesis. This Review focuses on the most recent advances made in the production of polyurethane materials from vegetable oils. Over the past several years, increasing attention has been given to the use of vegetable oils as feedstocks for polymeric materials, because they tend to be very inexpensive and available in large quantities. Using various procedures, a very broad range of polyols or diols and in some cases, poly- or diisocyanates, can be obtained from vegetable oils. The wide range of vegetable oil-based monomers leads to a wide variety of polyurethane materials, from flexible foams to ductile and rigid plastics. The thermal and mechanical properties of these vegetable oil-based polyurethanes are often comparable to or even better than those prepared from petroleum and are suitable for applications in various industries.

Novel polymeric materials from vegetable oils and vinyl monomers: preparation, properties, and applications

Veggie-based products: Vegetable-oil-based polymeric materials, prepared by free radical, cationic, and olefin metathesis polymerizations, range from soft rubbers to ductile or rigid plastics, and to high-performance biocomposites and nanocomposites. They display a wide range of thermophysical and mechanical properties and may find promising applications as alternatives to petroleum-based polymers.Vegetable oils are considered to be among the most promising renewable raw materials for polymers, because of their ready availability, inherent biodegradability, and their many versatile applications. Research on and development of vegetable oil based polymeric materials, including thermosetting resins, biocomposites, and nanocomposites, have attracted increasing attention in recent years. This Minireview focuses on the latest developments in the preparation, properties, and applications of vegetable oil based polymeric materials obtained by free radical, cationic, and olefin metathesis polymerizations. The novel vegetable oil based polymeric materials obtained range from soft rubbery materials to ductile or rigid plastics and to high-performance biocomposites and nanocomposites. These vegetable oil based polymeric materials display a wide range of thermophysical and mechanical properties and should find useful applications as alternatives to their petroleum-based counterparts.

Undecylenic acid: a valuable and physiologically active renewable building block from castor oil

A lot of attention is currently being paid to the transition to a biobased economy. In this movement, most efforts concentrate on the development of bioenergy applications including bioethanol, biodiesel, thermochemical conversion of biomass, and others. However, in the energy sector other nonbiomass alternatives are known, whereas no valuable alternatives are available when thinking about chemical building blocks. Therefore, it is also essential to develop new routes for the synthesis of bio-based chemicals and materials derived thereof. Such intermediates can originate either from plants or from animals. Castor oil is a non-edible oil extracted from the seeds of the castor bean plant Ricinus communis (Euphorbiaceae), which grows in tropical and subtropical areas. Globally, around one million tons of castor seeds are produced every year, the leading producing areas being India, PR China, and Brazil.2 10-Undecenoic acid or undecylenic acid is a fatty acid derived from castor oil that, owing to its bifunctional nature, has many possibilities to develop sustainable applications.