The impact of lignin addition on the properties of hybrid microspheres based on trimethoxyvinylsilane and divinylbenzene

• Hybrid microspheres of trimethoxyvinylsilane, divinylbenzene and lignin were synthesized by a suspension polymerization method. Commercially available alkali lignin and the methanol fraction of softwood kraft lignin were used as the bio-component of polymeric microspheres. The methanol fraction of lignin had a high content of phenolic groups and low molecular weight which are desirable features for further methacrylation. The physicochemical and electrokinetic properties of the synthesized materials were analyzed in detail. The preliminary modification of the hybrids with lignin had a noticeable positive effect on the stability and electrokinetic properties of the final products compared to those of unmodified microspheres composed of divinylbenzene and trimethoxyvinylsilane (DVB-TMVS). Thermal properties were investigated by differential scanning calorimetry and thermogravimetric analysis, and the morphology was studied using scanning electron microscopy. The microsphere texture was characterized using low-temperature nitrogen adsorption. The microspheres were mesoporous with a specific surface area in the range of 149–305 m2/g. The porosity of the hybrid materials was influenced by the type and modification of the lignin; microspheres with modified lignin in general had more developed porous structures. The applicability of the porous materials obtained as sorbents for the removal of dyes was confirmed in a batch experiment. The mechanism of interactions between dyes and a bio-sorbent containing lignin may involve electrostatic interactions between the positively charged nitrogen atoms of the dye molecule and the dissociated functional groups of the adsorbent, hydrogen bonding and π-π interactions.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Pappers-, massa- och fiberteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Paper, Pulp and Fiber Technology (hsv//eng)

Nyckelord

Lignin

Hybrid microspheres

Electrokinetic properties

Sorption

Fiber- och polymervetenskap

Fibre and Polymer Science

Publikations- och innehållstyp

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