Influence of Reaction Parameters on the Gelation of Silanised Linseed Oil.

Ewelina Depczyńska,Bartłomiej Mazela,Waldemar Perdoch

doi:10.3390/ma13235376

Ewelina Depczyńska, Bartłomiej Mazela + Show 1 more

Open Access

https://doi.org/10.3390/ma13235376

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Abstract

The subject of this work was to characterize the catalytic course of the linseed oil silylation reaction with vinyltrimethoxysilane (VTMOS), carried out under elevated pressure and temperature conditions, and an explanation of the reasons for rapid gelation of the reaction product. To explain and describe the process, analytical methods were used, i.e., 1H and 13C NMR (nuclear magnetic resonance), GC-FID (gas chromatography coupled with flame ionisation detection), and GPC (gel permeation chromatography). Reaction products were monitored after 3, 6 and 12 h. The molar mass of the VTMOS-modified oil in only 3 h was comparable with the molar mass of the product obtained by conventional polymerisation. An increase in the reaction time resulted in further transformations resulting from the hydrolysis and condensation reactions taking place. In contrast to reactivity of soybean oil, the silanisation of linseed oil occurred much faster and without the need for cross-linking catalysts. The reason for the high reactivity of linseed oil to VTMOS and rapid gelation of the resulting product was primarily the amount of double bonds present in linseed oil and their high availability, in particular the double bond in the acid linolenic acid located at the C16 carbon.

Highlights

The literature on the subject explicitly indicates that in the 21st century, triglyceride oils can be treated as the most important raw materials for the synthesis of polymers produced from renewable resources [1]
Since C16 carbon in Linolenic acid of linseed oil is involved in the polymerisation reaction, the VTMOS-fatty acid reaction can take place on the unconjugated C9 carbon atom or on the C16 atom by blocking the polymerisation
gel permeation chromatography (GPC) analysis confirmed the formation of polymers; it is very likely that VTMOS attacks the double bond with C9 Linolenic acid according to the

Summary

Introduction

The literature on the subject explicitly indicates that in the 21st century, triglyceride oils can be treated as the most important raw materials for the synthesis of polymers produced from renewable resources [1]. The presence of the oil/fatty acid chain in the polymer structure improves some of the polymer physical properties in terms of their flexibility, adhesion, resistance to water and chemicals resistance. Due to their source and structural nature, triglyceride oils can be widely used as pure polymers. The largest area of triglyceride oils’ application is concentrated in the field of coatings, including starting raw materials for the synthesis of other polymers, intended for varnish products [2]. Radical polymerisation is one of the common methods used to modify oils [1]. The radicals arising from the influence of the thermal energy or UV/VIS (Ultraviolet/Visible Spectroscopy) and an explanation of the reasons for rapid gelation of the reaction product radiation are responsible for initiating the reaction

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