No abstract

Glycerol esters are synthesized from rosin of Elliottii type by different methodologies and characterized in relation to the most relevant properties that define their quality for use in adhesive formulations. The produced esters have different properties due to the different synthesis recipes, mainly in relation to the percentage of glycerol and the type of additive used in the esterification. However, all cases showed great potential to be used as tackifiers resins in hot melt pressure sensitive adhesives (HMPSA).

The main goals of the present work are the production of bifunctional initiators through reactions between n‐butyl lithium (n‐BuLi) and divinylbenzene (DVB) and evaluation of the initiator performance in styrene polymerizations. Bifunctional initiators are desired for production of elastomers because they can be used to produce telechelic polymers. Initiators were prepared in solution in presence of the polar modifier 2,2‐ditetrahydrofurylpropane (DTHFP), used for solvation of the lithium cation and increase of the ion solubility in aliphatic hydrocarbons. It is shown that useful multifunctional initiators can be produced at the analyzed conditions, as indicated by the high average molar masses of the final product.

Multifunctional anionic initiators based on n‐BuLi and the diolefin m‐DIB (meta‐diisopropenylbenzene) were synthesized and stored at different temperatures, using different polar modifier contents and solvents. Solution styrene polymerizations were then used to evaluate the performances of the produced initiators. Based on the obtained results, it is shown that the best initiators were the ones prepared at 40 °C, using the DTHFP/BuLi molar feed ratio of 0.1 in cyclohexane. At these preparation conditions, the produced initiator has higher contents of multifunctional species and presents higher stability. The DTHFP/n‐BuLi ratio of 0.1 was shown to be the most appropriate because it minimizes the formation of oligomers and allows for suitable initiation of styrene polymerizations.

1,3-butadiene (1,3-BD) is a building block produced mainly as a byproduct of the ethylene steam cracking process. However, due to the growing interest in sustainable technologies, there is also growing interest in manufacturing 1,3-BD from ethanol. For this reason, taking into account that the ethanol-derived 1,3-BD can contain oxygenated contaminants that are difficult to remove, the present manuscript investigates for the first time how the presence of low concentrations of some oxygenates (acetaldehyde, crotonaldehyde, 3-hydroxybutyraldehyde, acetone, water, ethanol, 1,3-butanodiol, 3-buten2-ol, crotyl alcohol, and 1-butanol) in the 1,3-BD monomer can affect polymerization reactions performed with the neodymium versatate catalyst and modify the characteristics of the obtained polybutadiene products. It is shown that the presence of oxygenated compounds can cause inhibitory effects on the course of the polymerization and modify the molar mass distributions and flow properties of the final products, although all analyzed samples presented the characteristic high-cis character of polybutadienes produced with the neodymium versatate catalyst.