Bio-based resins

The raw materials used in the production of phenolic resins (phenol and formaldehyde) are obtained on a large scale from non-renewable sources. Therefore, the substitution of these reagents by equivalent chemicals obtained from non-fossil sources is an interesting alternative from both economic and environmental perspectives (Razera and Frollini, 2004 Hoareau et al., 2006 Paiva and Frollini, 2006). Moreover, substituting formaldehyde with other aldehydes obtained from renewable sources could eliminate the potential emission of formaldehyde during the use of phenolic resins (Ramires et al., 2010a). 

The saccharification and fermentation of sugarcane bagasse or other lignocellulosic fibers in biorefineries is a promising process for the production of bioethanol (Lacerda et al., 2012 Hemandez-Salas et al., 2009), which 

Tannins are considered polyphenols due to the large number of phenolic rings in their structures (Mosiewicki et al., 2007 Moubarik et al., 2009). These natural products can be found in certain plant tissues, such as bark, fruit and wood, and can be removed from these sourees by extraction with water. Tannins are classified in two groups hydrolyzable tannins and condensed tannins (Mueller-Harvey, 2001). The condensed tannins are flavonoids with complex structures (Fig. 2.5). The phenolic groups present in tannin enable this macromolecule to participate in the same reactions as phenol (Tondi and Pizzi, 2009). Condensed tannins are more suitable than the hydrolyzable type for use in the manufacture of a phenolic-type polymeric matrix due to the presence of phenolic rings with a greater number of free positions where the electrophilic attack can occur (Barbosa et al., 2010). The high reactivity of 

4 Main units in non-wood plant lignin and schematic representation of lignin-formaldehyde pre-polymers (Ramires et al., 2010b Malutan et al., 2008). 

5 Schematic representation of condensed tannins and tannin-phenolic pre-polymers (Barbosa et aL, 2010 Ramires and Frollini, 2012). 

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At the same time, prices for the three major types of bio-based resins, starch-based biopolymers, polylactic acid (PLA) and aliphatic aromatic co-polyester, have dropped considerably over the last... 

Historically, pricing had been the biggest barrier to biodegradable polymer market development. However, growing volumes of production and the development of new technology should further allow bio-based resin makers to reduce costs. Using materials such as corn stover, wheat straw and rice straw, which remain in fields after crops are harvested, as resin feedstock, could also increase productivity and economic performance. 

Biomass-based fiiran resins use furfuryl alcohol (FA) [17]. It has affected the success of the rather old biomass-based chemical industry. This reactive alcohol plays a vital role in the production of foundry sand binders. For over 30 years these fiiran resins have been extensively used in the foundry industry to produce cores that yield high-quality castings. Despite the good chemical, mechanical and thermal properties of FA resins/polymers such as corrosion resistance, fiame retardancy, low smoke emission and excellent char formation, the consumption of these bio-based resins in other markets is of minor significance ... 

Mahendran, A.R., Aust, N., Wuzefla, G. and Kandelbauer, A. (2012) Synthesis and characterization of a bio-based resin from Unseed oil. Macromolecular Symposia, 311, 18-27. 

Vegetable oil-modified biocomposites are broadly defined as composites of vegetable oil-based resins and synthetic fibres or of bio-based resins and natural fibres. The conventional vegetable oil-based composites mainly consist of a vegetable oil-based polymers matrix. This has been discussed in earlier chapters and the dispersed phase or reinforcing agents, which may be synthetic or natural fibres, are discussed here. 

Bio-PET Popularity of bio-PET is due to its successful application in beverage bottles. Polyester is made by polycondensation of EG with terephthalic acid [TPA]. Bio-based EG is made from molasses, sugarcane, switchgrass, and bagasse via their fermentation into ethanol. Using this bio-EG with fossil fuel-based TPA, a PET that is partially bio-based is obtained. The PlantBottle by Coca-Cola in 2009 is made using this partly (22.5%) bio-based resin. The Bio-PET is recyclable. 

Key words phenolic-type resins, bio-based resins, synthesis, phenolic-type composites, reinforcements, properties. 

For instance cardanol, a phenol-based by-product of the cashew nut industry, is one of the common precursors used to obtain different types of epoxy bio-based resins. Cardanol is an industrial grade yellow oil obtained by vacuum distillation of cashew nut shell liquid (CNSL), the international name for the alkyl phenolic oil contained in the spongy mesocarp of the cashew nut shell from the cashew tree Anacardium occidentale L. CNSL derived from the most diffused roasted mechanical processes of the cashew industry represents nearly 25% of the total nut weight, and its production worldwide (Africa, Asia and South America being the main producer areas) is estimated to be about 300,000 tons per year (Calo et al., 2007). 

Plant oils and animal fat are mostly unsatured fatty acids. Some of these oily products are already well known by the public from their use in paint (e.g., flax (linseed) tung oils are drying oils used in paints, varnishes and enamels) or in soaps, detergents, cosmetics and lubricant applications. Plant oils increasingly become a source of raw material to produce thermoset resins that can be mixed widi natural fibres in order to achieve light and resistant composite materials. The combination of bio-based resins with natural fibres (plant and poultry) or... 

Bio-Rex 70 2.4 0.70 Weakly acidic cation exchanger with car-boxylate groups on a macroreticular acrylic matrix for separation and fractionation of proteins, peptides, enzymes, and amines, particularly high molecular weight solutes. Does not denature proteins as do styrene-based resins. 

Ion exchange resins are also useful for demineralising biochemical preparations such as proteins. Removal of metal ions from protein solutions using polystyrene-based resins, however, may lead to protein denaturation. This difficulty may be avoided by using a weakly acidic cation exchanger such as Bio-Rex 70. 

Polymerization of Bionolle 3001 (polybutylene succinate/adipate) using bio-based and petro-based succinic acid was examined. As for polymerization conditions and processability, there was no significant difference between these two types of resin. Mechanical properties of blown films processed from both resins were almost the same. The quality of bio-based succinic acid turned out to be good enough as a polymer grade. 

Osaka-based Mitsui Chemicals Inc. is increasing production of its Lacea-brand PLA resin. The bio-based material has been used in electronics packaging, envelope windows and prepaid phone cards. Most recently, Honda Motor Co. Ltd. of Tokyo has used Lacea PLA in packaging straps at its auto plants. 

Bio-based and recycled polymers often have short-lifecycles compared to oil-based virgin resins. We studied bio-based (PAX) and recycled (PA6) polyamide (PA) blends [LOU 13]. Scanning electron microscopy (Figure 12.4) shows that the formulations are composed of 75% PA6 and 25% PAX by mass (denoted PA6/PAX (25/75)) and PAX nodules appear in the PA6 matrix. To refine the morphology and improve PA6/PAX interfaces, we conducted reactive compatibilization to couple the... 

Though the overall impact result of the hemp/epoxy composite was lower than the impact of the glass/epoxy composite, the impact associated with the matrix was very high. There are two ways to reduce the impacts associated with the matrix one is using bio-based matrix, the other is using a recycled matrix. Many studies involve the use of bio-based epoxy resin in thermoset composites, while recycled polypropylene and recycled polyethylene have been studied in new thermoplastic formulations. 

Looking at the different types of plastics and their applications large differences in the share of bio-based materials can be found. In 2010, the German Eederal Agency for Renewable Resources presented data for the German market in the year 2007, which was analysed in three different sectors thermoplastic and thermoset resins, elastomers, and man-made fibres (Figure 1.2). 

This book focuses on bio-based plastics. It emphasizes materials that are presently in use or that show a significant potential for future applications. It presents a broad, up-to-date but concise overview of basic and applied aspects of bioplastics. The main focus is on thermoplastic polymers for material use. Elastomers, thermosets and coating applications, Uke, for example, natural rubber or alkyd resins, will be covered in other volumes of the series. 

Hirayama, K.-I, Irie, T, Teramoto, N. and Shibata, M. (2009) High-performance bio-based thermosetting resins composed of dehydrated castor oil and bismaleimide. Journal of Applied Polymer Science, 114(2), 1033-1039. 

Lu, J. and Wool, R.P. (2008) Additive toughening effects on new bio-based thermosetting resins from plant oils. Composites Science and Technology, 68(3-4), 1025-1033. 

The bio-related resin polylactic acid is well known as a renewable material. However, renewable materials such as this lack the mechanical and thermal properties to be of any practical use. hi order to overcome these drawbacks, the synthesis of clay nanocomposites based on renewable materials has been discussed. These materials are known as Green Nanocomposites [44] and are now forming a new sector in materials studies. 

In our research we used AESO resin for producing wheat straw particleboards. Since both raw materials are derived from nature, this kind of particleboard is totally a bio-based product, without any use of forestry resources (wood particles) or any formaldehyde emissions (because AESO does not contain any formaldehyde). We made the boards, evaluated their physical and mechanical properties and eventually compared the results to wood particleboard EN-standards. 

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