The Interaction Effect of the Design Parameters on the Water Absorption of the Hemp-Reinforced Biocarbon-Filled Bio-Epoxy Composites.

Natural fiber-reinforced composites perform poorly when exposed to moisture. Biocarbon has been proven to improve the water-absorbing behavior of natural fiber composites. However, the interaction effect of the design parameters on the biocarbon-filled hemp fiber-reinforced bio-epoxy composites has not been studied. In this study, the effects of the design parameters (pyrolysis temperature, biocarbon particle size, and filler loading) on the water absorptivity and water diffusivity of hemp-reinforced biopolymer composites have been investigated. Biocarbon from the pyrolysis of hemp and switchgrass was produced at 450, 550, and 650 °C. Composite samples with 10 wt.%, 15 wt.%, and 20 wt.% of biocarbon fillers of sizes below 50, 75, and 100 microns were used. The hemp fiber in polymer composites showed a significant influence in its water uptake behavior with the value of water absorptivity 2.41 × 10-6 g/m2.s1/2. The incorporation of biocarbon fillers in the hemp biopolymer composites reduces the average water absorptivity by 44.17% and diffusivity by 42.02%. At the optimized conditions, the value of water absorptivity with hemp biocarbon and switchgrass biocarbon fillers was found to be 0.72 × 10-6 g/m2.s1/2 and 0.73 × 10-6 g/m2.s1/2, respectively. The biocarbon at 650 °C showed the least composite thickness swelling due to its higher porosity and lower surface area. Biocarbon-filled hemp composites showed higher flexural strength and energy at the break due to the enhanced mechanical interlocking between the filler particles and the matrix materials. Smaller filler particle size lowered the composite's water diffusivity, whereas the larger particle size of the biocarbon fillers in composites minimizes the water absorption. Additionally, higher filler loading results in weaker composite tensile energy at the break due to the filler agglomeration, reduced polymer-filler interactions, reduced polymer chain mobility, and inadequate dispersion of the filler.

The Potential Application of Starch and Walnut Shells as Biofillers for Natural Rubber (NR) Composites.

The goal of this study was application of corn starch and ground walnut shells in various amounts by weight as biofillers of natural rubber (NR) biocomposites. Additionally, ionic liquid 1-butyl-3-methylimidazolium chloride (BmiCl) and (3-aminopropyl)-triethoxysilane (APTES) were used to increase the activity of biofillers and to improve the curing characteristics of NR composites. The effect of biofillers used and their modification with aminosilane or ionic liquid on the curing characteristics of NR composites and their functional properties, including crosslink density, mechanical properties in static and dynamic conditions, hardness, thermal stability and resistance to thermo-oxidative aging were investigated. Starch and ground walnut shells were classified as inactive fillers, which can be used alternatively to commercial inactive fillers, e.g., chalk. BmiCl and APTES were successfully used to support the vulcanization and to improve the dispersion of biofillers in NR elastomer matrix. Vulcanizates with starch, especially those containing APTES and BmiCl, exhibited improved tensile properties due to the higher crosslink density and homogenous dispersion of starch, which resulted from BmiCl addition. NR filled with ground walnut shells demonstrated improved resistance to thermo-oxidative aging. It resulted from lignin present in walnut shells, the components of which belong to polyphenols, that have an antioxidant activity.

Potential Application of Peppermint (Mentha piperita L.), German Chamomile (Matricaria chamomilla L.) and Yarrow (Achillea millefolium L.) as Active Fillers in Natural Rubber Biocomposites.

In this study, peppermint (Mentha piperita L.), German chamomile (Matricaria chamomilla L.) and yarrow (Achillea millefolium L.) were applied as natural fibrous fillers to create biocomposites containing substances of plant origin. The purpose of the work was to investigate the activity and effectiveness of selected plants as a material for the modification of natural rubber composites. This research was the first approach to examine the usefulness of peppermint, German chamomile and yarrow in the field of polymer technology. Dried and ground plant particles were subjected to Fourier transmission infrared spectroscopy (FTIR) and UV-Vis spectroscopy, thermogravimetric analysis (TGA), goniometric measurements (contact angle) and scanning electron microscopy (SEM). The characterization of natural rubber composites filled with bio-additives was performed including rheometric measurements, FTIR, TGA, cross-linking density, mechanical properties and colour change after simulated aging processes. Composites filled with natural fillers showed improved barrier properties and mechanical strength. Moreover, an increase in the cross-linking density of the materials before and after the simulated aging processes, compared to the reference sample, was observed.

Evaluation of Marginal Adaptation of Composite Restorations Reinforced with Novel Enamel Inserts (Biofillers) in Class V Cavities.

AIM AND OBJECTIVE: To evaluate the marginal adaptation at the tooth-restoration interface at enamel and cementum margins using composite restoration reinforced with novel enamel inserts/biofillers. MATERIALS AND METHODS: Standardized class V box-shaped cavities were prepared in 40 extracted maxillary first premolar teeth which were divided randomly into four experimental groups consisting of 10 samples each. Group I: Bulk placement. Groups II: Horizontal incremental technique. Group III: Restoration with precured composite balls (megafillers). Group IV: Restoration with biofillers. All the cavities were restored with visible light-activated direct restorative nanocomposite. The specimens were thermocycled for 24 hours. After thermocycling, the samples were immersed in a 1% methylene blue for 4 hours and subsequently evaluated for microleakage. Microleakage scores (0-4) were obtained from gingival margins of class V restorations and analyzed by statistical analysis. Evaluation of the data was performed by Kruskal-Wallis one-way analysis of variance (ANOVA), and Mann-Whitney U tests. RESULTS: Microleakage scores have indicated restorations with biofillers showed best results followed by megafillers, incremental horizontal build-up, and bulk filling. CONCLUSION: Biofillers provide a novel approach in improving microleakage and marginal adaptability of composite resin restorations. CLINICAL SIGNIFICANCE: Incorporation of inserts, which are capable of adequate bonding to resin and tooth, may provide improved marginal adaptability and reduce microleakage around restorative margins.

The Effect of Rapeseed Oil Biopolyols and Cellulose Biofillers on Selected Properties of Viscoelastic Polyurethane Foams.

This paper presents the results of research on polyurethane viscoelastic foams (PUVFs) modified with biomaterials. This investigation looked at the effect of the biomaterials on the foaming processes, as well as the acoustical and selected physical-mechanical properties of the foams. Various types of rapeseed oil biopolyols and microcellulose were used to modify the materials. The analysis of properties covered a reference biopolyol-free sample and materials containing 10 wt.%, 20 wt.%, and 30 wt.% of different types of biopolyols in the mixture of polyol components. The biopolyols differed in terms of functionality and hydroxyl value (OHv). Next, a selected formulation was modified with various microcellulose biofillers in the amount of 0.5-2 wt.%. The PUVFs, with apparent densities of more than 210 kg/m3 and open-cell structures (more than 85% of open cells), showed a slow recovery to their original shape after deformation when the pressure force was removed. They were also characterized by a tensile strength in the range of 156-264 kPa, elongation at break of 310-510%, hardness of 8.1-23.1 kPa, and a high comfort factor of 3.1-7.1. The introduction of biopolyols into the polyurethane system resulted in changes in sound intensity levels of up to 31.45%, while the addition of fillers resulted in changes in sound intensity levels of up to 13.81%.

Novel nano composites from Citrus limon and Citrullus colocynthis agricultural wastes for biomedical applications.

In recent years, academic and industrial research has focused on using agro-waste for energy and new material production to promote sustainable development and lessen environmental issues. In this study, new nanocomposites based on polyvinyl alcohol (PVA)-Starch using two affordable agricultural wastes, Citrus limon peels (LP) and Citrullus colocynthis (Cc) shells and seeds powders with different concentrations (2, 5, 10, and 15 wt%) as bio-fillers were prepared. The nanocomposites were characterized by Dielectric Spectroscopy, Fourier-Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and water swelling ratio. The antimicrobial properties of the nanocomposites against Escherichia coli, Staphylococcus aureus, and Candida albicans were examined to investigate the possibility of using such composites in biomedical applications. Additionally, the biocompatibility of the composites on human normal fibroblast cell lines (HFB4) was tested using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. The results demonstrate that the filler type and concentration strongly affect the film's properties. The permittivity ε', dielectric loss ε″ and conductivity σdc increased by increasing filler content but still in the insulators range that recommend such composites to be used in the insulation purposes. Both bio fillers control the water uptake, and the samples filled with LP were more water resistant. The polyvinyl alcohol/starch incorporated with 5 wt% LP and Cc have antimicrobial effects against all the tested microorganisms. Increasing the filler content has a negative impact on cell viability.

Elastomeric Compositions of Ethylene-Norbornene Copolymer Containing Biofillers Based on Coffee and Tea Waste.

The development of eco-friendly elastomeric materials has become an important issue in recent years. In this work, thermoplastic elastomer samples of an ethylene-norbornene copolymer (EN) with coffee and tea biofillers mixed with typical fillers such as montmorillonite (MMT), silica (SiO2), and cellulose were investigated. The aim of this research was to determine the effect of fillers on the properties of the materials and to assess their degradability after two ultraviolet (UV) aging cycles (200, 400 h). The scientific novelty of this work is the assessment of the anti-aging effect of simultaneous biofillers-stabilizers based on coffee and tea waste. The surfaces of the obtained polymer compositions were examined using infrared spectroscopy (FTIR-ATR). Contact angles were determined, and surface energy was calculated. The mechanical properties were tested, and the influence of plant fillers and aging on the color change in the materials was analyzed. The combination of coffee with silica, MMT, and cellulose fillers limited the migration of fatty acids and other compounds from the biofiller to the EN surface (FTIR analysis). Based on the aging coefficients K, it was shown that all coffee- and tea-based fillers stabilized the polymer compositions during UV aging (400 h). The results allowed the authors to determine the importance and impact of waste plant fillers on the degradability of the synthetic EN.

Fully Bio-Based Polymer Composites: Preparation, Characterization, and LCD 3D Printing.

The present work aimed to prepare novel bio-based composites by adding fillers coming from agro-wastes to an acrylate epoxidized soybean oil (AESO) resin, using liquid crystal display (LCD) 3D printing. Different photocurable formulations were prepared by varying the reactive diluents, iso-bornyl methacrylate (IBOMA) and tetrahydrofurfuryl acrylate (THFA). Then, two fillers derived from different industrial wastes, corn (GTF) and wine (WPL-CF) by-products, were added to the AESO-based formulations to develop polymer composites with improved properties. The printability by LCD of the photocurable formulations was widely studied. Bio-based objects with different geometries were realized, showing printing accuracy, layer adhesion, and accurate details. The thermo-mechanical and mechanical properties of the 3D-printed composites were tested by TGA, DMA, and tensile tests. The results revealed that the agro-wastes' addition led to a remarkable increase in the elastic modulus, tensile strength, and glass transition temperature in the glassy state for the systems containing IBOMA and for flexible structures in the rubbery region for systems containing THFA. AESO-based polymers demonstrated tunable properties, varying from rigid to flexible, in the presence of different diluents and biofillers. This finding paves the way for the use of this kind of composite in applications, such as biomedical for the realization of prostheses.

A review on sliding wear properties of sustainable biocomposites: Classifications, fabrication and discussions.

Biocomposites have gained huge attention in the field of manufacturing. They are widely accepted over conventional petroleum-based composites due to less environmental footprint and safer living habitats, abundance, availability, recyclability, reusability, and end-life disposals. The potential applications of biocomposites are now widely accepted in key engineering areas such as automotive, construction, consumer products, and aerospace industries. Concurrently, tribological properties for biopolymer composites are an appealing research direction. In this review article, a comprehensive literature survey of recent progress made in sliding wear properties of biocomposites are discussed in detail. It summarizes natural and synthetic ways to attain tribological performances in biocomposites such as biopolymers with bio-fillers, biopolymers with synthetic/inorganic fillers, and non-biopolymers with bio-fillers. The study gives a deeper understanding of the crucial informations regarding sliding wear properties of biocomposites and thereby aid in the future research in the design and preparation of similar composites.

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

The aim of this work was application of ground eggshells in various amounts by weight as a biofiller for natural rubber (NR) biocomposites. Cetyltrimethylammonium bromide (CTAB), ionic liquids (ILs), i.e., 1-butyl-3-methylimidazolium chloride (BmiCl) and 1-decyl-3-methylimidazolium bromide (DmiBr), and silanes, i.e., (3-aminopropyl)-triethoxysilane (APTES) and bis [3-(triethoxysilyl)propyl] tetrasulfide (TESPTS), were used to increase the activity of ground eggshells in the elastomer matrix and to ameliorate the cure characteristics and properties of NR biocomposites. The influence of ground eggshells, CTAB, ILs, and silanes on the crosslink density, mechanical properties, and thermal stability of NR vulcanizates and their resistance to prolonged thermo-oxidation were explored. The amount of eggshells affected the curing characteristics and crosslink density of the rubber composites and therefore their tensile properties. Vulcanizates filled with eggshells demonstrated higher crosslink density than the unfilled sample by approximately 30%, whereas CTAB and ILs increased the crosslink density by 40-60% compared to the benchmark. Owing to the enhanced crosslink density and uniform dispersion of ground eggshells, vulcanizates containing CTAB and ILs exhibited tensile strength improved by approximately 20% compared to those without these additives. Moreover, the hardness of these vulcanizates was increased by 35-42%. Application of both the biofiller and the tested additives did not significantly affect the thermal stability of cured NR compared to the unfilled benchmark. Most importantly, the eggshell-filled vulcanizates showed improved resistance to thermo-oxidative aging compared to the unfilled NR.

Influence of Enzymatically Hydrophobized Hemp Protein on Morphology and Mechanical Properties of Bio-Based Polyurethane and Epoxy Foams.

Biomass fillers offer the possibility to modify the mechanical properties of foams, increasing their cost-effectiveness and reducing their carbon footprint. In this study, bio-based PU (soft, open cells for the automotive sector) and epoxy (EP, hard, closed cells for construction applications) composite foams were prepared by adding pristine and laccase-mediated lauryl gallate-hydrophobized hemp protein particles as filler (HP and HHP, respectively). The fillers were able to modify the density, the mechanical properties and the morphology of the PU and EP foams. The addition of HP filler increases the density of PU foams up to 100% and significantly increases the σ values by 40% and Emod values. On the other hand, the inclusion of the HHP as filler in PU foams mostly results in reduced density, by almost 30%, and reduced σ values in comparison with reference and HP-filled foams. Independently from filler concentration and type, the biomass increased the Emod values for all foams relative to the reference. In the case of the EP foams, the tests were only conducted for the foams filled with HHP due to the poor compatibility of HP with the EP matrix. HHP decreased the density, compressive strength and Emod values of the composites. For both foams, the fillers increased the size of the cells, while reducing the amount of open cells of PU foams and the amount of closed cells for EP foams. Finally, both types of foams filled with HHP reduced the moisture uptake by 80 and 45%, respectively, indicating the successful hydrophobization of the composites.

Fruit Peel Powder as Natural Antioxidant and Reinforcing Bio-Filler in Natural Rubber Latex Gloves: Cases of Mangosteen, Pomelo and Durian.

As the world is facing rapid increases in agricultural wastes that greatly affect global health, the environment, and economies, this work aims to alleviate such issues by introducing simple uses of waste fruit peel powder (FPP) derived from mangosteen (MPP), pomelo (PPP), or durian (DPP), as dual natural antioxidants and reinforcing bio-fillers in natural rubber latex (NRL) gloves. A thorough investigation was undertaken of the relevant characteristics for both FPP (morphological, functional groups, particle sizes, and thermals stability) and NRL gloves (morphological, functional groups, density, color, thermal stability, and mechanical properties-both before and after thermal/25 kGy gamma aging). The results indicated that the initial addition (2-4 parts per hundred parts of rubber by weight; phr) of FPP to NRL composites generally enhanced the strength and elongation at the break of the specimens, with the levels of the improvement varying depending on the type and content of FPPs. In addition to the reinforcing effects, the FPP also offered natural antioxidant properties, evidenced by higher values of aging coefficients for all FPP/NRL gloves under either thermal or 25 kGy gamma aging than those of pristine NRL. Furthermore, by comparing the tensile strength and elongation at break of the developed FPP/NRL gloves with the requirements for medical examination latex gloves according to ASTM D3578-05, the recommended FPP contents for actual glove production were 2-4 phr for MPP, 4 phr for PPP, and 2 phr for DPP. Consequently, based on the overall outcomes, the FPPs of interest showed promising potential for utilization as simultaneous natural antioxidants and reinforcing bio-fillers in NRL gloves, which would not only enhance the strength and ability of the gloves to resist oxidative degradation from heat and gamma irradiation but also increase their economical value as well as reducing the amounts of the investigated wastes.

Influence of Biofillers on the Properties of Regrind Crystalline Poly(ethylene terephthalate) (CPET).

As the demand for plastics only increases, new methods are required to economically and sustainably increase plastic usage without landfill and environmental accumulation. In addition, the use of biofillers is encouraged as a way to reduce the cost of the final resin by incorporating agricultural and industrial waste by-products, such as rice hulls and coffee chaff to further reduce waste being sent to landfills. Crystalline poly(ethylene terephthalate) (CPET) is a resin commonly used for microwave and ovenable food packaging containers that have not been fully explored for recycling. In this article, we investigate how the incorporation of biofillers at 5% wt. and 10% wt. impacts critical polymer properties. The thermal and mechanical properties were not significantly altered with the presence of rice hulls or coffee chaff in the polymer matrix at 5% wt. loading, but some reduction in melt temperature, thermal stability, and maximum stress and strain was more noticed at 10% wt. The complex viscosity was also reduced with the introduction of biofillers. The levels of heavy metals of concern, such as Cd, Cr, and Pb, were below the regulatory limits applicable in the United States and Europe. Additional studies are suggested to improve the performance of CPET/biofiller blends by pre-treating the biofiller and using compatibilizers.

The Role of Inorganic-Organic Bio-Fillers Containing Kraft Lignin in Improvement in Functional Properties of Polyethylene.

In this study, MgO-lignin (MgO-L) dual phase fillers with varying amounts of lignin as well as pristine lignin and magnesium oxide were used as effective bio-fillers to increase the ultraviolet light protection and enhance the barrier performance of low density polyethylene (LDPE) thin sheet films. Differential scanning calorimetry (DSC) was used to check the crystalline structure of the studied samples, and scanning electron microscopy (SEM) was applied to determine morphological characteristics. The results of optical spectrometry in the range of UV light indicated that LDPE/MgO-L (1:5 wt/wt) composition exhibited the best protection factor, whereas LDPE did not absorb ultraviolet waves. Moreover, the addition of hybrid filler decreased the oxygen permeability factor and water vapor transmission compared with neat LDPE and its composites with pristine additives, such as lignin and magnesium oxide. The strong influence of the microstructure on thin sheet films was observed in the DSC results, as double melting peaks were detected only for LDPE compounded with inorganic-organic bio-fillers: LDPE/MgO-L.

Potential applications of polycarbohydrates, lignin, proteins, polyacids, and other renewable materials for the formulation of green elastomers.

Renewable resources including polycarbohydrates, lignin, proteins, and polyacids are the intrinsically valuable class of materials that are naturally available in great quantities. Their utilization as green additives and reinforcing bio-fillers, in substitution of environmentally perilous petroleum-based fillers, for developing high-performance green rubber blends and composites is presently a highly tempting option. Blending of these renewable materials with elastomers is not straight-forward and research needs to exploit the high functionality of carbohydrates and other natural materials as proper physicochemical interactions are essential. Correlating and understanding the structural properties of lignin, carbohydrates, polyacids, and other biopolymers, before their incorporation in elastomers, is a potential approach towards the development of green elastomers for value-added applications. Promising properties i.e., biodegradability, biocompatibility, morphological characteristics, high mechanical properties, thermal stability, sustainability, and various other characteristics along with recent advancements in the development of green elastomers are reviewed in this paper. Structures, viability, interactions, properties, and use of most common natural polycarbohydrates (chitosan and starch), lignin, and proteins (collagen and gelatin) for elastomer modification are extensively reviewed. Challenges in commercialization, applications, and future perspectives of green elastomers are also discussed. Sustainability analysis of green elastomers is accomplished to elaborate their cost-effectiveness and environmental friendliness.

Wine By-Products as Raw Materials for the Production of Biopolymers and of Natural Reinforcing Fillers: A Critical Review.

The plastic industry is today facing a green revolution; however, biopolymers, produced in low amounts, expensive, and food competitive do not represent an efficient solution. The use of wine waste as second-generation feedstock for the synthesis of polymer building blocks or as reinforcing fillers could represent a solution to reduce biopolymer costs and to boost the biopolymer presence in the market. The present critical review reports the state of the art of the scientific studies concerning the use of wine by-products as substrate for the synthesis of polymer building blocks and as reinforcing fillers for polymers. The review has been mainly focused on the most used bio-based and biodegradable polymers present in the market (i.e., poly(lactic acid), poly(butylene succinate), and poly(hydroxyalkanoates)). The results present in the literature have been reviewed and elaborated in order to suggest new possibilities of development based on the chemical and physical characteristics of wine by-products.

Waterborne Intumescent Coatings Containing Industrial and Bio-Fillers for Fire Protection of Timber Materials.

Flammability and combustion of softwood treated with intumescent coatings were studied in the present work. The formulations applied onto wood surfaces contained different ratios of industrial fillers, titanium dioxide TiO2 and aluminium trihydroxide Al(OH)3, and/or bio-fillers, eggshell and rice husk ash. Combustion behaviours of unprotected and protected wood samples have been examined with the aid of cone calorimetry performed under the varied levels of thermal flux ranging from 30 to 50 kW/m². The char residues obtained after the completion of cone calorimetry test at 40 kW/m² were analysed by the Raman spectroscopy. The fire protective properties of the studied coatings were strongly influenced by the nature of the fillers as well as by the intensity of thermal irradiance. The incorporation of bio-based fillers into the water-based intumescent formulations significantly improved fire resistance of wood substrates. For example, at 30 kW/m², the Effective Heat of Combustion was reduced by more than 40%, whilst the average Peak to Heat Release Rate had dropped from 193.2 to 150.3 kW/m² for the wood sample protected with the formulation incorporating two industrial and two bio-fillers. Moreover, an application of the studied coatings resulted in a notable reduction of the back surface temperature of the wood specimens.

Use of Biomaterials for 3D Printing by Fused Deposition Modeling Technique: A Review.

Three-dimensional (3D) printing is a revolutionary manufacturing technique that can fabricate a 3D object by depositing materials layer by layer. Different materials such as metals, polymers, and concretes are generally used for 3D printing. In order to make 3D printing sustainable, researchers are working on the use of different bioderived materials for 3D printing. Because of the abundant and sustainable sources, and versatile properties, biomaterials are considered as the potential candidates that have the ability to replace petroleum-based polymers. This review highlights the basic overview of fused deposition modeling (FDM) technique of 3D printing and recent developments that have occurred on FDM printing using biomaterials. Specifically, FDM printing process, final properties, and characteristics of biopolymers, their composites, and polymers containing biofillers are discussed.

Additive Manufacturing of Geopolymers Modified with Microalgal Biomass Biofiller from Wastewater Treatment Plants.

This paper deals with the additive manufacturing of metakaolin-based geopolymers and with the use of microalgal biomass from wastewater treatment plants as biofiller in this kind of cementitious material. The study was developed following the evolution stages of the material, which was prepared and printed as a soft paste and then hardened thanks to an inorganic polymerization reaction (geopolymerization). Thus, the characterization techniques adopted encompassed rheometry, mechanical tests performed on the hardened material, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and mercury intrusion porosimetry (MIP). Microalgal biomass addition, evaluated in this study at 1, 3 and 5 php with respect to the powder weight, affected both the properties of the fresh and of the hardened material. Regarding the former aspect, biomass reduced the yield stress of the pastes, improving the ease of the extrusion process, but potentially worsening the ability to build structures in height. When hardened, geopolymers containing microalgae showed mechanical properties comparable to the unfilled material and a microstructure characterized by smaller pores. Finally, a printing test was successfully performed with a larger printer to assess the feasibility of producing large-scale structures. Taking into account these results, this study demonstrates the possibility of using microalgal biomass as biofiller in geopolymers for additive manufacturing.

Thermal, structural and acetylation behavior of snail and periwinkle shells chitin.

This article reports a successful removal of CaCO3 from snail and periwinkle shells for the purpose of producing high quality chitin for possible application as bio-fillers in bone fixation materials. Experiment was designed with varying concentrations of acid and alkali for demineralization, deproteinization and deacetylation of the samples. Thermal characteristics, morphology, degree of de-acetylation, crystalline structure and hydrogen bonding characteristics of the extracted chitin were examined. Infra-red spectra, thermogravimetric analysis and X-ray diffraction patterns show that demineralization with 1.7 M HCl led to a successful removal of CaCO3. Subsequent deproteinization and deacetylation with 1.2 M NaOH led to a development of chitosan having a degree of deacetylation of 77 and 60% for periwinkle and snail shells, respectively. Generally, all results show that different treatments led to different chitin structure and consequently different properties.