Waste Eggshells as a Natural Filler for the Poly(Vinyl Chloride) Composites

Abstract

The paper presents the characteristics of unplasticized PVC composites modified with biofiller obtained from the waste eggshells of hen eggs. The composites obtained by extrusion contained from 10 phr to 40 phr of biofiller. The filler was characterized using the SEM, TG, and sieve analysis methods. The influence of the filler on the processing properties was determined using plastographometric and MFR tests. Fundamental analysis of mechanical properties was also performed, i.e., Charpy impact strength and determination of tensile properties. The mechanical properties were supported with dynamical mechanical thermal analysis, time of thermal stability, and thermogravimetric analysis. Structure analysis was also performed using SEM and X-ray microcomputed tomography (micro-CT). The processing properties of the tested composites do not give grounds for disqualifying such material from traditional processing PVC mixtures. Notably, the biofiller significantly improves thermal stability. Ground eggshells (ES) work as scavengers for the Cl radicals released in the first stage, which delays the PVC chain’s decay. Additionally, a significant increase in the value of the modulus of elasticity and softening point (VST) of the composites concerning PVC was found. Ground hen eggshells can be used as an effective filler for PVC composites.

Potential Utilization of Ground Eggshells as a Biofiller for Natural Rubber Biocomposites

“…The residue after decomposition at 1100 • C was 51.4% for eggshells and 57.2% for CaCO 3 , respectively. Therefore, the ground eggshells contained of approximately 94% mineral compounds, i.e., CaCO 3 , whereas the organic part was approximately 6% mineral compounds, which is consistent with the literature [49,56].…”

“…In the case of CaCO 3 , the mass loss in the temperature range of 650-900 • C was attributed to the emission of gaseous carbon dioxide (CO 2 ) [49,52,53]. The presence of a similar mass loss on the TG curve of eggshells in the temperature range of 650-900 • C confirmed that the eggshells contained CaCO 3 .The removal of CO 2 from CaCO 3 led to the calcium oxide (CaO) as a mineral residue after thermal decomposition [54][55][56]. The residue after decomposition at 1100 • C was 51.4% for eggshells and 57.2% for CaCO 3 , respectively.…”

Modification of Poly(vinyl chloride) with Bio-Based Cassia Oil to Improve Thermo-Mechanical and Antimicrobial Properties

“…261 °C is associated with an intensive decomposition of plasticiser, while the T DTG3 maximum of approx. 293 °C is associated with the dechlorination of PVC macromolecules [ 45 , 52 ]. The next stage above 400 °C is attributed to the crosslinking of chains containing C=C bonds, as the process of thermal degradation of polyenes involves cyclization and the splitting of chains [ 53 ].…”

“…The relatively small amplitude and low strain frequency allow for a measurement in a linear viscoelastic range with a low value of the loss modulus [ 44 ]. The glass transition temperature ( T g ) was determined based on changes in the value of the storage modulus (E′) as a function of temperature at the beginning of a rapid decrease in value E′ ( T g onset) [ 45 ]. From the DMA thermograms obtained, the maximum values of the loss modulus (E″) and tan δ were established.…”

Bio-Based White Eggshell as a Value-Added Filler in Poly(Lactic Acid) Composites

“…For instance, eggshells [20][21][22][23] and clam seashell powder [24] were added as filler materials in PP matrices. Similarly, eggshells have been incorporated into LDPE [25,26], HDPE [27], and poly(vinyl chloride) [28].…”