Preparation and analysis of polypropylene composites with maleated tea dust particles

Abstract

In this research work, the recycling of waste tea dust particles was done by preparing the injection moulded polypropylene (PP) composites using different (10–40 wt.%) loadings of tea dust particles as a filler. The tea dust particles were treated with maleic anhydride (MA) and its esterification effect was studied on physico-mechanical (morphology, mechanical, thermal and swelling) properties of tea dust:polypropylene (TD:PP) composites. Surface modification of tea dust particles was observed due to the MA treatment i.e. the esterification effect. The surface morphology of the composites showed better interfacial bonding between the maleated tea dust particles and PP than the untreated particles. The mechanical properties of the maleated TD:PP composites were found to be improved (200–300% higher tensile strength, 250% higher tensile modulus, 43% higher flexural strength and 10% higher hardness) as compared to untreated TD:PP composites. Crystallinity and thermal properties of the maleated TD:PP composites showed increasing trend with increase in filler content. Water absorption tests showed that maleated TD:PP composites absorb less water than that of untreated one. The increment in all these properties is due to the greater compatibility in tea dust particles and PP by MA treatment. Thus, tea dust particles can be suggested for preparation of composite materials.

Elaboration of performance of tea dust–polypropylene composites

“…This treatment eliminated low molecular weight species and hemicelluloses . In previous study, FTIR spectra revealed that surface treatment of TD particles can remove hemicelluloses, lignin type materials and which was confirmed from the absence of spectra (1370–1330 cm −1 of in‐plane CH bending of hemicelluloses and 1505–1520 cm −1 for lignin) in treated TD particles. These TD particles were denoted as “styrene treated TD” (STD) particles.…”

“…Ratio of TD:PP (40:60) was kept suitable for surface treatment using styrene and to study the improvement in properties. This ratio (40:60) was already tested and showed improvement in physicomechnical properties of STD:PP composites, as per previous study . The UTD and STD particles were precisely weighed and mixed with PP in the different weight ratios (10:90, 20:80, 30:70, and 40:60) as shown in Table .…”

“…Then PP composites were prepared by reinforcing the STD particles in matrix. Molecular mechanism and FTIR spectra of untreated and MA and tetra ethyl silane treated TD particles have been discussed . Surface treatment has been confirmed from XRD analysis.…”

“…Waste TD particles were collected from the tea stalls after use. TD is generally composed of moisture, ash, lignin, cellulose, and hemicellulose type materials …”

“…Compatibilizer and coupling agent normally enhance the compatibility of the two phases in polymer composites, for example, MA treated and silane treated TD:PP composites . Montecelli et al used different coupling agents for the treatment of fibers and reported that the degree of hydrolysis could enhance the bonding strength of the composite.…”