EPOXIDISED LINSEED OIL

The linear diblocks are then coupled by a polyfunctional coupling agent such as epoxidised linseed oil to give a star-shaped polymer. As already mentioned, commercial materials of this type have a tetramodal distribution. 

The number of epoxy groups per molecule will vary but for modified soya bean oils there are an average of about four whereas there are about six for epoxidised linseed oils. 

Epoxidised soybean oil (ESBO) Epoxidised linseed oil (ELO) Primary use as a secondary heat stabiliser but also impart flexibility. Compatible only at relatively low addition levels. General use... 

Boquillon, N. and Fringant, C. (2000) Polymer networks derived from curing of epoxidised linseed oil influence of different catalysts and anhydride hardeners. Polymer, 41(24), 8603-8613. 

Vegetable oil-based polyols obtained by epoxidation are treated with diisocyanates in the presence of a suitable chain extender and catalyst to obtain polyurethanes (Fig. 6.5). Polyurethanes have been prepared from olive, peanut, canola, corn, soybean, safflower and sunflower oil by the conventional epoxidation process, followed by treatment of the polyols of the epoxies with diphenylmethane diisocyanate. Polyurethane resins may also be obtained by the treatment of soybean polyols (which are obtained by methanolysis of epoxidised soybean oil with isocyanates at a temperature of 50°C) or from epoxidised linseed oil with TDI using xylene as the solvent. 

Blends of poly(methacrylic acid) or polystyrene with epoxidised linseed oil are prepared in solution by mechanical mixing in dimethyl sulphoxide (DMSO) or tetrahydrofuran (THF) to improve the performance of the individual components. However, blends of poly(methylacrylic acid) are not able to produce compatible systems, although different compositions (15-55 wt%) of polystyrene blends will form miscible blends. The results show an improvement in properties, including biodegradation of the miscible blends, and the systems are comparable with low density polyethylene. 

Anhydride cured combined epoxy of epoxidised linseed oil or epoxidised soybean oil with bisphenol-A-based diglycedyl ether epoxy, gives a high elastic modulus, high glass transition temperature, a high Izod impact... 

Nanocomposites were prepared from epoxidised linseed oil after copolymerisation with 3-glycidyl propyl heptaisobutyl-T8-polyhedral oUgomeric sUsesquioxanes (G-POSS). Owing to reinforcement by inorganic POSS derivatives, enhanced values and storage moduli of the networks in the glassy state and rubber plateau were observed compared to pristine epoxy. ... 

Now, if 75% styrene and 25% butadiene are polymerized together in a different way then, a totally different material results it is a plastic rather than a rubber. This is done by sequential, anionic polymerization in solution. As a result a material is produced which contains long lengths (or blocks) of polystyrene and long lengths (or blocks) of polybutadiene may contain up to, for example, six blocks. The molecules of the final plastic are star shaped as the initial multiblocks are coupled together by a polyfunctional material, for example, epoxidised linseed oil. (Because of the polymerization technique employed, plastics with a narrow molecular weight distribution may be produced if required). 

Scheme 4.4 Reaction of epoxidised linseed oil with diamines [13]...

Use of anhydride hardeners to crosslink epoxidised oils has received more attention. Boquillon and Fringant [19] studied the kinetics of the polycondensation of epoxidised linseed oil with various aromatic and cycloaliphatic anhydrides at 150-170 °C and characterised the ensuing networks by measuring their Tg and flexural modulus (which both increased with increasing proportion of anhydride) as well as dynamic mechanical properties and their crosslink density. These materials, based partly on renewable resources, displayed adequate properties in terms of applications of thermosets associated with a relatively low Tg (35-110 °C). A similar investigation in which epoxidised vegetable oils substituted with <50% of bisphenol A diglycidyl... 

Scheme 6.9 Reaction of aminated grapeseed oil with epoxidised linseed oil. AGSO Amino-grafted soybean oil and ELO epoxidised linseed oil [31]...

These studies opened the way to a new area of macromolecular science based on renewable resources pursued by approaches based on pristine oils and their commercial derivatives. The bulk reaction of epoxidised vegetable oils with an excess of furfurylamine was studied in green chemistry conditions and formd to take place through two parallel mechanisms occurring at approximately the same rate. That is, aminolysis of ester bonds and oxirane ring-opening, as shown in Scheme 7.5 for the case of epoxidised linseed oil [12], These reactions were followed by Fourier-Transform infrared spectroscopy and H-nuclear magnetic resonance spectroscopy, respectively, and both reached completion. 

Scheme 7.5 Double insertion of furfurylamine into epoxidised linseed oil [12]...

The amoimt of plasticiser required can sometimes be reduced by replacing part of it with a different, cheaper softening agent, sometimes known as an extender. Extenders have similar effects to plasticisers, but are not capable of completely replacing them because of their inadequate compatibility. Examples include the chlorinated hydrocarbons, epoxidised soya bean oil and epoxidised linseed oil. These last two substances have already been described as plasticisers the boimdaiy between plasticisers and extenders is not sharp, becanse compatibiUty depends on the formulation. Note that the term extender is sometimes used for other low cost additives designed to bulk out the volume of a mix, such as cheap fillers. 

Lankroflex L Epoxidised Linseed Oil Lankroflex E2307 Epoxidised Soya Bean Oil Lankroflex E2414 E xidised Soya Bean Oil Lankroflex EDS Octyl Epoxy Stearate... 

The biopolymers covered in this book chapter are Starch polymers, polyhydroxyalkanoates (PHA), polylactides (PLA), lignin-epoxy resins, epoxidised linseed oil and composites reinforced with natural fibres such as flax, hemp, and china reed (miscanthus). The first three materials are biodegradable while this is not the case for the remaining studied materials. 

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