A one-step method of plant oil direct transesterification was used to synthesize new vinyl monomers from sunflower (SFM), linseed (LSM), soybean (SBM), and olive (OVM) oils. The degree of unsaturation in plant oil fatty acids was used as a criterion to compare the free radical polymerization behavior of new monomers. The number-average molecular weight of plant oil-based homopolymers synthesized in toluene in the presence of AIBN at 75 °C varies at 11 000–25 000 and decreases as follows: poly­(OVM) > poly­(SFM) > poly­(SBM) > poly­(LSM), corresponding to increasing degree of unsaturation in the monomers. Rate of polymerization depends noticeably on the degree of unsaturation in monomers. Due to the allylic termination, chain propagation coexists with effective chain transfer during polymerization. The obtained values of C M (ratio of chain transfer and propagation rate constants) depends on monomer structure as follows: C M(LSM) > C M(SBM) > C M(SFM) > C M(OVM). 1H NMR spectroscopy shows that the fraction of the reacting allylic atoms does not vary significantly for the synthesized monomers (7–12%) and is determined entirely by plant oil degree of unsaturation. The glass transition temperature of homopolymers [T g = 4.2 °C for poly­(SFM), T g = −6 °C for poly­(SBM)] from new monomers indicates that varying biobased fragments in copolymers might considerably change the intermolecular interactions of macromolecules and their physicochemical properties.

ABSTRACT:Investigations of terpolymerization kinetics of the system on the basis of vinyl acetate (VA), peroxidic monomer (VEP) 2-tert-butyl-peroxy-2-methyl-5-hexene-3-yne, and acrylic acid proved that it falls under the equation of faintly inhibited copolymerization in which VEP serves as a comonomer and a chain-transfer agent. The contribution of each stage to the summary process rate is defined by the monomer ratio and depends on their consumption rate. Combination of a low-active VA monomer and of a VEP faint inhibitor in the system allows the control of the Trommsdorf effect and molecular-weight characteristics of functional oligoperoxides by changing the component ratio. The new carbon chain oligomers containing ditertiary alkyl peroxide and polar functional groups have practical application as multicenter surface-active radical initiators of polymerization and structurization.

In recent years, polymer chemistry has experienced an intensive development of a new field regarding the synthesis of aliphatic and aromatic biobased monomers obtained from renewable plant sources. A one-step process for the synthesis of new vinyl monomers by the reaction of direct transesterification of plant oil triglycerides with N-(hydroxyethyl)acrylamide has been recently invented to yield plant oil-based monomers (POBMs). The features of the POBM chemical structure, containing both a polar (hydrophilic) fragment capable of electrostatic interactions, and hydrophobic acyl fatty acid moieties (C15-C17) capable of van der Waals interactions, ensures the participation of the POBMs fragments of polymers in intermolecular interactions before and during polymerization. The use of the POBMs with different unsaturations in copolymerization reactions with conventional vinyl monomers allows for obtaining copolymers with enhanced hydrophobicity, provides a mechanism of internal plasticization and control of crosslinking degree. Synthesized latexes and latex polymers are promising candidates for the formation of hydrophobic polymer coatings with controlled physical and mechanical properties through the targeted control of the content of different POBM units with different degrees of unsaturation in the latex polymers.

Today coatings made from renewable biobased resources are still being over performed by coatings made from petroleum-based sources in the way they act mechanically, thus leaving them less useful from the industrial standpoint. Such properties of films/coatings as toughness or rigidness are accessible for control through regulating their cross-link density. As the curing process continues, the double bonds that do not get polymerized are capable of reforming to link the alkyl groups of monomers together, thus varying the cross-link density of the material. Use of plant-oil-based monomers in this case can be advantageous because the amount of unsaturation of the fatty acid chains in those monomers is generally much higher than that of their petro-based counterparts and can be regulated. Using the developed in our group one-step method of plant oil direct transesterification, a library of acrylic monomers has been recently synthesized [1-4]. Using emulsion and miniemulsion polymerization latexes from new monomers based on plant oils (soybean, linseed, canola, sunflower, high oleic soybean, olive, hydrogenated soybean oil) (POBMs) with remarkably different amount of unsaturation (compositions of fatty acids in oil triglycerides) have been developed. Presence of plant oil-based fragments impacts thermomechanical properties of latex films by decreasing glass transition temperature (thus, providing plasticizing effect) of latex copolymers. The thermomechanical properties of resulting latex nanoparticles depend considerably on the amount of incorporate oil-derived fragments. Biobased ingredient makes latex copolymers more flexible, improves material film forming properties, provides some flexibility and toughness, as compared to the normally rigid polystyrene and poly(methyl methacrylate). In addition, plant oil-based fragments enhance hydrophobicity of the resulting latex films and can be considered as additives to reduce water sensitivity of the polymer. At this point, stable latexes containing up to 70 wt% of biobased content can be synthesized using the miniemulsion process of copolymerization of POBMs with different vinyl counterparts. Their unsaturation amount can be utilized as a criterion in studying the resulting latex properties, including the effect of variation in monomer feed unsaturation on the crosslink density of latex films and, consequently, on polymer thermal and mechanical properties. It is observed that in oxidatively cured latex films, the crosslink density depends linearly on reaction feed unsaturation. Based on that, the latex network thermomechanical properties can be adjusted by simply combining various plant oil-based monomers at certain ratios ("given" unsaturations) in the reaction feed.

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