Biobased Content Research Articles

Evaluation of Biobased Content of Biobased Polymer by Measuring Carbon-14 Using Accelerator Mass Spectrometry

Evaluation of Biobased Content of Biobased Polymer by Measuring Carbon-14 Using Accelerator Mass Spectrometry

Carbon footprint of bioplastics using biocarbon content analysis and life-cycle assessment

Abstract

Impact of Structure and Functionality of Core Polyol in Highly Functional Biobased Epoxy Resins

Highly functional biobased epoxy resins were prepared using dipentaerythritol (DPE), tripentaerythritol (TPE), and sucrose as core polyols that were substituted with epoxidized soybean oil fatty acids, and the impact of structure and functionality of the core polyol on the properties of the macromolecular resins and their epoxy-anhydride thermosets was explored. The chemical structures, functional groups, molecular weights, and compositions of epoxies were characterized using nuclear magnetic resonance (NMR) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, gel permeation chromatography (GPC), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI MS). The epoxies were also studied for their bulk viscosity, intrinsic viscosity, and density. Crosslinked with dodecenyl succinic anhydride (DDSA), epoxy-anhydride thermosets were evaluated using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), tensile tests, and tests of coating properties. Epoxidized soybean oil (ESO) was used as a control. Overall, the sucrose-based thermosets exhibited the highest moduli, having the most rigid and ductile performance while maintaining the highest biobased content. DPE/TPE-based thermosets showed modestly better thermosetting performance than the control ESO thermoset.

High Biobased Content Epoxy–Anhydride Thermosets from Epoxidized Sucrose Esters of Fatty Acids

Novel highly functional biobased epoxy compounds, epoxidized sucrose esters of fatty acids (ESEFAs), were cross-linked with a liquid cycloaliphatic anhydride to prepare polyester thermosets. The degree of cure or conversion was studied using differential scanning calorimetry (DSC), and the sol content of the thermosets was determined using solvent extraction. The mechanical properties were studied using tensile testing to determine Young's modulus, tensile stress, and elongation at break. Dynamic mechanical analysis (DMA) was used to determine glass-transition temperature, storage modulus, and cross-link density. The nanomechanical properties of the surfaces were studied using nanoindentation to determine reduced modulus and indentation hardness. The properties of coatings on steel substrates were studied to determine coating hardness, adhesion, solvent resistance, and mechanical durability. Compared with the control, epoxidized soybean oil, the anhydride-cured ESEFAs have high modulus and are hard and ductile, high-performance thermoset materials while maintaining a high biobased content (71-77% in theory). The exceptional performance of the ESEFAs is attributed to the unique structure of these macromolecules: well-defined compact structures with high epoxide functionality. These biobased thermosets have potential uses in applications such as composites, adhesives, and coatings.

Biobased-Chemical Toner Prepared from Palm oil Derivatives

One of major challenge in bio-toner making was how to increase the amount of bio content. Palm oil based alkyd polyester was synthesized through step growth polymerization, mixed with styrene monomer (Sty) and butyl-acrylate (Ac) as co-monomer to produce the hybrid latex. Different levels of alkyd polyester incorporation were studied. Flocculation process was carried out using the hybrid latex with different alkyd resin percentage mixed with other additives like coagulant, wax, charge control agent, and pigment to produce bio-chemical toner, Palmotone™ CPT. The increasing intensity of OH stretching peak from pure Sty-Ac latex (standard) to highest alkyd polyester containing latex showed alkyd resin was well incorporated into styrene acrylic system. Besides, bio-based content analysis (ASTM D6866) revealed that percentage of renewable carbon to total carbon is increasing when alkyd polyester level increased. In addition, it was proven in this paper that the desirable properties in chemical toners are still achievable with the usage of palm oil based alkyd polyester. Furthermore, incorporation of bio-based materials will create a great versatility and hence serves various requirements in chemical toner applications, covering wide range of printers and copiers in the market. Higher level of incorporation is still under further study.

Interlaboratory Variability of Radiocarbon Results Obtained from Blind AMS Analyses on Several Modern Carbon Samples

Three samples of modern-day vegetation collected in 2009–2010 and a sample of bioethanol produced in 2010 were analyzed for radiocarbon by 5 different accelerator mass spectrometry (AMS) laboratories in a blind analysis study. The magnitude of any variability in the reported results for percent modern carbon (pMC) was observed. Results indicated that the interlaboratory repeatability on the samples of vegetation was generally very good, varying by no more than ~1 pMC for 2 of the 3 samples. Results for the bioethanol were less consistent, and varied by 5.5 pMC (ranging from 101.9 to 107.4 pMC). Variations in the δ13C values used to correct for isotopic fractionation did not account for the variability observed in the pMC values for this sample. In view of the homogeneity of the bioethanol and its inherent simplicity in composition, this suggests that volatile liquid fuels may be more difficult to prepare for analysis without incurring significant sample processing errors. When viewing all of the results as a whole, the analytical errors (incorporating both instrumental and sample processing errors) appeared to be more random than systematic in nature. Because of analytical uncertainties in pMC measurements, as well as inherent local and regional variations in 14C activity levels known to occur in modern-day biomass, there is not a precise (accurate to 2 decimal places) correction factor for negating the bomb carbon effect that is applicable to all biofuels or other biobased products being analyzed in accordance with ASTM Method D6866. Therefore, a reasonable correction factor (currently set at 0.95) needs to be consistently applied in order to make comparisons of biobased content data from different laboratories more valid. Results from this study indicate that, for samples containing predominantly modern carbon, reporting results to the nearest 0.1 pMC is not warranted.

Epoxidized High-Oleic Vegetable Oils Applied to Composites

Vegetable oils are a renewable source for the production of oleochemicals. Oils with high oleic and low saturate content may be an excellent source for producing epoxy resins because of the uniform distribution of cross-linking sites. Bio-based epoxy resins can be used as matrix components for composite materials. Vegetable oils with oleic acid content varying from 22% to 86% were epoxidized in situ with peracetic acid and a heterogeneous catalyst. Contents of 30%, 35%, and 40% (% wt of total matrix) of bio-based epoxy resins were blended with a synthetic epoxy resin and an anhydride curing agent to be applied as the matrix in the preparation of composites using E-glass as the structural fiber. A control was also prepared with a 100% synthetic epoxy resin. Mechanical properties (flexural properties, interlaminar shear strength, and dynamic mechanical analysis) of the produced composite materials were evaluated. More flexible but less resistant composites were obtained as the content of oleic acid in the initial vegetable oil and the content of bio-based resin increased. Toughness increased at lower levels of oleic acid content. Interlaminar shear strength showed low adhesion of the matrix-fiber at a bio-based epoxy resin content of 40%. High homogeneity and slightly reduced glass transition temperatures were shown in composites with high-oleic bio-based resins when compared with the control. The application of bio-based epoxy resins in the production of composites materials helps decrease the dependence on petroleum-based resins and may lead to a high added-value product from vegetable oils. However, future studies are needed to increase the adhesion of matrices containing bio-based resin with synthetic and natural fibers, which will improve the mechanical performance of the composites.

MATERIALS Coca-Cola to introduce biobased content for bottle plastic

The heaviest hitter in the beverage industry is taking a swing at biobased materials. Later this year, Coca-Cola Co. will introduce bottles for its Dasani-brand water with up to 30% biobased content. Beverage bottles are typically created from polyethylene terephthalate (PET), made, in turn, by reacting ethylene glycol and terephthalic acid. The ethylene glycol in the new Dasani bottles will be derived from sugar and molasses, rather than its usual origin in petroleum and natural gas. Coca-Cola won’t disclose the names of the chemical companies from which it is sourcing the glycol. Michael Schultheis, Coca-Cola’s director of sustainable packaging design, tells C&EN that his company will procure the sugar and molasses from India and Brazil. An Indian firm, India Glycols, boasts of being the world’s only producer of glycol made from molasses. Its stated production capacity is 125,000 metric tons per year, via ethanol and ethylene oxide. Brazil’s only glycol producer is Oxiteno, which ...

Ozone removal by green building materials

There is a rapidly expanding market for green building materials. Such materials are intended to be environmentally friendly, with such characteristics as low toxicity, minimal chemical emissions, ability to be recycled, and durability. In addition, green materials often contain recycled and/or bio-based contents. Consequently, some green materials may undergo significant oxidation with potential for reduction of indoor ozone. In this study, 48-L electro-polished stainless steel chambers were used to study the reactive consumption of ozone by ten common green wall, flooring, ceiling, and cabinetry materials (perlite-based ceiling tile, unglazed ceramic tile, natural cork wall-covering, aluminum tinted cork wall-paper, bamboo, UV-coated bamboo, wheat board, UV-coated wheat board, sunflower board, and UV-coated sunflower board). Ozone removal was quantified in terms of deposition velocity and reaction probability. Ozone removal decreased with time after initial exposure, but for several materials the ability to react with ozone was regenerated after a period of zero ozone exposure. Test materials found to have the highest ozone reaction probabilities were a perlite-based ceiling tile, natural cork wall-covering, and wheat board.

Considerations Regarding Inorganic Carbon in the Determination of "Biobased Content" Using Radiocarbon Analyses

Considerations Regarding Inorganic Carbon in the Determination of "Biobased Content" Using Radiocarbon Analyses

Compostability of polymers

AbstractIn recent years, biobased polymers have gained attention from industries, consumers and governments as a way to reduce municipal solid waste. Much attention has been given to their production and implementation. However, these materials only reach their potential environmental benefits when they are recovered through recycling or composting and/or their energy is recovered by incineration. These end‐of‐life scenarios allow closing the carbon cycle loop. A lot of confusion and misunderstanding about these new materials and their end‐of‐life scenarios, particularly composting, have been generated. This paper addresses definitions and environmental performance of these materials and their compostability. Current methods for measuring biobased content and biodegradability of polymers and factors affecting it, such as exposure conditions and polymer characteristics, are discussed, and the use of life cycle assessment as a tool to evaluate the environmental performance of biopolymers is presented. Although there are some obstacles for the growth and implementation of biobased polymers, such as consumer adoption and available composting facilities accepting these materials, new opportunities are growing due to government regulation and business initiatives in the past five years. However, consumers' understanding of when the use of these materials provides environmental benefits and when not is still missing. Therefore, to adopt and to implement these new biopolymers cooperative work among industry, consumers and government is needed. Copyright © 2008 Society of Chemical Industry

Biobased Contents of Organic Fillers and Polycaprolactone Composites with Cellulose Fillers Measured by Accelerator Mass Spectrometry Based on ASTM D6866

The biobased contents of raw materials such as starches, sugar, chitin, or wood powders for biomass plastics were measured using Accelerator Mass Spectrometry (AMS) based on ASTM D6866. AMS measures the isotope carbon ratio of 14C to 12C and 13C in graphite derived from sample powders. The biobased contents of starches, sugar or chitin were almost 100% which means that they are fully biobased. The biobased contents of the wood powders were over 140% due to the effect of the post 1950s 14C injection due to nuclear testing. Poly(e-caprolactone) (PCL) composite samples were prepared using the polymerization and direct molding method. The starting compound was the e-caprolactone monomer liquid combined with cellulose and inorganic fillers using aluminum triflate as a catalyst at 80 °C for 6 or 24 h. PCL cylinder-shaped composite samples with a homogeneously dispersed cellulose filler were prepared with Mn = 4,600 (Mw/Mn = 2.9). The biobased content of the PCL composite with 50 wt% cellulose filler (51.67%) measured using AMS was slightly higher than the carbon ratio of cellulose in the starting powder samples (41.3 mol%). This is due to the higher biobased content (112.70%) of the cellulose filler used in this study. The biobased content of the polymer composite powders by AMS was found not to be affected by the presence of inorganic fillers, such as talc.

Biobased Contents of Biodegradable Poly(ε‐caprolactone) Composites Polymerized and Directly Molded Using Aluminium Triflate from Caprolactone with Cellulose and Inorganic Filler

Poly(epsilon-caprolactone) (PCL) composite samples were prepared by polymerization and direct molding. The starting compound was epsilon-caprolactone monomer liquid combined with cellulose and inorganic fillers, using aluminium triflate as a catalyst at 80 degrees C, for 6 or 24 h. Cylinder-shaped PCL composite samples with a homogeneously dispersed cellulose filler were prepared with (-)M(n) = 4 600 ((-)M(w)/(-)M(n) = 2.9). The mechanical properties of the PCL composite samples were studied using compression test methods. The strength of a PCL composite with 50 wt.-% cellulose filler (10.8 MPa) was found to be lower than the PCL sample without fillers (19.2 MPa). The biobased content of the PCL composite with 50 wt.-% cellulose filler (51.67%) measured using accelerated mass spectrometry (AMS) was slightly higher than the carbon ratio of cellulose in the starting powder samples (41.3 mol-%). The biobased content of the polymer composite powders by AMS was found not to be affected by the presence of inorganic fillers, such as talc. The rate and extent of biodegradation, caused by Amano Lipase PS, of the PCL composite sample with cellulose filler (40% degradation in 4 d) was the same as that of a PCL sample without the cellulose filler.

Accuracy of radioanalytical procedures used to determine the biobased content of manufactured products

Radiocarbon analyses were used to determine the “biobased content” of a variety of diverse samples. The theoretical biobased contents of those samples were compared to the biobased content values obtained by radiocarbon analyses. Results of this work indicated that the radiocarbon analyses provided accurate (within ± 3%, absolute) biobased content values for the samples tested. It is not practical to examine the accuracy of the radiocarbon analyses for every possible type of sample matrix. However, based on analyses performed on various types of samples, every indication is that the analyses provide accurate and reliable results on the biobased content of liquid and solid materials.

Determining the modern carbon content of biobased products using radiocarbon analysis

In support of the USDA Federal Biobased Products Preferred Procurement Program (FB4P), Iowa State University is coordinating testing to determine the “biobased content” of manufactured products. These tests are part of a process to “designate” items that qualify for preferential procurement status with federal agencies. Biobased content determinations are being performed using three radiocarbon dating procedures specified in ASTM D 6866-05. Test results obtained thus far indicate that the AMS and benzene synthesis methods provide comparable results. Data from the CO 2 cocktail method did not agree as well with the data from the other two methods, but were still in reasonably good agreement with those data. Radiocarbon analysis is shown to be a reliable and valuable tool for verifying the biobased content of a wide variety of biobased products. Based on inter- and intra-laboratory comparisons, a reasonable uncertainty to associate with the analyses would be ±3% (absolute) for the AMS and benzene synthesis methods. Because of limited data availability, additional work is needed to establish the uncertainty of the CO 2 cocktail method for analyzing biobased products.