Increase In Impact Strength Research Articles

Functionalized halloysite nanotubes endowing epoxy resin with simultaneously enhanced flame retardancy and mechanical properties

In order to impart epoxy resin (EP) with desired flame retardancy, thermal stability and mechanical properties, a novel flame retardant HNT@PZM@Fe(OH)3 with hierarchical core–shell-dot structure was successfully constructed in this work. The shell layer composed of polyphosphazene (PZM) effectively facilitated the interface interaction between halloysite nanotube (HNT) and polymer matrix, and significantly reinforced the EP nanocomposites (26.6 % increase in tensile strength and 31.5 % increase in impact strength when introduced with 5 wt% HNT@PZM@Fe(OH)3). Owing to the interfacial catalysis of transition metal compounds and barrier effect of HNT, EP/HNT@PZM@Fe(OH)3 performed remarkably in flame retardancy and smoke suppression. Upon the incorporation of 5 wt% HNT@PZM@Fe(OH)3, EP nanocomposites possessed the limiting oxygen index (LOI) of 30.8 %, reaching UL-94 V-0 rating. Cone calorimeter tests proved a distinct fall in the peak of heat release rate (PHRR) and smoke production rate (SPR) of EP/5HNT@PZM@Fe(OH)3, being respectively 65.8 % and 57.1 % compared to EP. The relevant tests revealed that the interfacial charring catalysis of transition metal oxides was beneficial to the formation of residual char structure with higher graphitization degree, which further improved the fire safety. Our work has provided aresearch basisand promising prospect for the production of high-efficient flame retardant EP nanocomposites.

Mechanical Properties of Hybrid Composites PMMA Denture Base with Varying Concentrations of Nano-ZrO<sub>2</sub> and Glass Fiber

Studying the effects of hybrid reinforcement made of nano-zirconium oxide and chopped glass fibers for poly methyl methacrylate (PMMA) denture bases, nano- ZrO2 (n ZrO2) at grain sizes (46.7 nm) which measured using Atomic Force Microscopy (AFM) and different ratios on the mechanical characteristics was the aim of this study .To make the pure sample, a 2:1 powder to liquid ratio of typical acrylic resin was used. Hybrid composites with varying concentrations of nano-ZrO2 (nZrO2) and glass fiber (GFs) (2.5%nZrO2+2.5% GFs), (3.5%nZrO2+1.5%GFs), (1.5%nZrO2+3.5% GFs) were introduced. Mechanical tests as tensile strength, flexural strength, impact strength, shore D hardness are used to learn about the properties of manufactured composites. Antibacterial testing, water absorption, density testing, and thermal conductivity these indicated that composites may be effectively turned into filler material. In addition to X-ray diffraction (XRD), Scanning Electron Microscopy (SEM). The result show increased the mechanical properties of the PMMA denture base material. The tensile strength flexural strength, and impact strength increase for all hybrid ratio and reach maximum value at the concentration (2.5%nZrO2+2.5% GFs) compared to unreinforced PMMA.While hardness increase and reach maximum value at the concentration (3.5%nZrO2+1.5% GFs). In addition, thermal conductivity and density, the maximum value at concentration (1.5%nZrO2+3.5% GFs), as well as water absorption decrease as ratio of nZrO2 increase this shoed in concentration (3.5wt. % nZrO2 +1.5wt. %, GFs).

Investigation of Impact Properties of Carboxylated‐terminated Liquid Acrylonitrile Rubber and Cerium Oxide Nano Double‐toughened Epoxy Resin

AbstractThe excellent physical properties of epoxy resin are not available in other thermoplastic materials, but the toughness of pure species samples is relatively poor. In this experiment, epoxy resin was toughened by adding carboxylated‐terminated liquid acrylonitrile rubber and cerium oxide nanoparticles. The samples were subjected to performance tests, including impact tests, scanning electron microscopy, Energy Dispersive Spectroscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, and Thermal stability analysis. Based on the analysis of the performance test results, the best toughening mass ratio of the raw material of the double toughened epoxy resin was obtained. The mass ratio of epoxy resin to double toughening agent was 4 : 1. In the double toughening agent, the mass ratio of carboxylated‐terminated liquid acrylonitrile rubber to cerium oxide nano was 4 : 1. The impact strength of the double toughened epoxy resin at the optimum toughened mass ratio can reach 31.77 KJ/m2. This is an impact strength increase of 692 % compared with the pure epoxy resin.

Enhancing toughness, flame retardant, hydrophobic and dielectric properties of epoxy resin by incorporating multifunctional additive containing phosphorus/silicon

Developing epoxy resins with superior toughness, flame retardant and hydrophobic as well as dielectric properties remains a huge challenge. Herein, an epoxy additive (ETP) was prepared by grafting phosphorus-containing molecules into the skeleton of silicone resin through silicon hydrogen addition reaction. Through such a design, the obtained ETP imparted Bisphenol A epoxy resin (DGEBA) with excellent flexibility, fire safety, hydrophobicity and dielectrical property. When only 6 wt% of ETP was introduced into the DGEBA system, the resulting product (ETP-6) passed the V-0 level in the UL-94 test with a high limiting oxygen index of 29.8 %, which could be ascribed to the presence of phosphorus and silicon element. Meanwhile, compared with neat DGEBA, the peak heat releases and smoke emissions of ETP-6 were reduced by 32.7 % and 37.8 % during the combustion. Additionally, ETP also imparted the cured product with excellent hydrophobic and dielectric properties, as well as superior toughness (114.5 % increase in impact strength) due to its “rigid and flexible” silicone skeleton and good dispersion. This work opens up a new strategy for developing high-performance and multifunctional epoxy resin additives with potential versatile applications.

Morphological, Mechanical and Thermal Properties of Polybutylene Tetrephthalate‐Polyester Based Thermoplastic Polyurethane Blends

AbstractPolybutylene tetrephthalate (PBT)‐polyester based thermoplastic polyurethane (TPU) blends with varying percentages of TPU (10 %, 20 %, 30 %, 40 %) were prepared in order to improve impact strength of PBT to enhance its applications. The blends were prepared by melt mixing using a twin screw extruder. Based on morphological images, impact strength analysis and dynamical mechanical analysis, TPU was well dispersed in PBT polymer matrix. Studies using Differential Scanning Calorimetry indicate a decrease in crsytallinity on addition of 30 % TPU in PBT. Thermogravimetric analysis demonstrates that addition of TPU in PBT matrix increases the char content. PBT and TPU have a good interfacial adhesion, according to SEM investigations. Mechanical characteristics demonstrate that the inclusion of TPU in PBT matrix resulted in a significant increase in impact strength of about 208 %, with minor changes in tensile strength and tensile modulus. Change in glass transition temperature of the optimised blend was measured using DMA.

Investigation of the effects of deep cryogenic treatment on the structural and mechanic properties of polyoxymethylene copolymer (POM-C) materials

Polyoxymethylene is used as an engineering material in many fields such as aircraft, aviation, and automotive industries in today due to its thermal resistance and mechanical properties. In this study, it is aimed to investigate the effects on the mechanical and structural properties of polyoxymethylene copolymer (POM-C) materials, which are used in many different industrial applications, by applying cryogenic treatment. For this purpose, deep cryogenic treatment was applied to the prepared samples at −175°C for 6, 12, 18, and 24 h, and then tensile, abrasion, impact, and hardness tests were applied to the samples that were kept at room temperature. In order to understand the changes in micro and crystal structures, XRD (X-Ray Diffraction), SEM (Scanning Electron Microscope), and FTIR (Fourier Transform Infrared Radiation) analyzes were performed, and based on these analyzes, the differences in the structure of the POM-C material were compared. It was observed that there was no improvement in the tensile strength of the deep cryogenically treated samples, but an increase in hardness and impact strength was detected.

Experimental study of compressive strength, permeability and impact testing in geopolymer concrete based on Blast furnace slag

Cement production has always been associated with environmental challenges due to carbon dioxide emissions. On the other hand, cement production is an energy-intensive process and leads to the consumption of abundant fossil fuels. In order to solve this problem, the production of geopolymer concrete is on the agenda. The researchers decided to reduce the negative effects of cement production and have superior properties than ordinary concrete. In the current study, slag-based geopolymer concrete was used with 0-2% polyolefin fibers and 0-8% nano-silica to improve its structure. After curing the specimens under dry conditions at a temperature of 60°C in an oven, they were subjected to compress strength, tensile strength and Drop weight hammer tests to evaluate their mechanical properties, as well as Permeability test to assess their durability. tests were performed at 7 and 90 days of age at ambient temperature (20℃). The addition of nano-silica enhanced the whole properties of the slag-based geopolymer concrete. Increasing the curing age improved the results of all tests. The results of all tests in geopolymer concrete showed the superiority of the results over conventional concrete. At the 28-day curing age, the addition of up to 8% nanosilica to the geopolymer concrete composition improved the compressive strength test results by 19.01%, water permeability by up to 35% and impact strength by up to 36.36%. Addition of up to 2% of polyolefin fibers in the composition of geopolymer concrete resulted in a 28.95% decrease in compressive strength but a 20% improvement in water permeability and an 8.26-fold increase in impact strength. In the following, by conducting the SEM test, a microstructure investigation was carried out on the concrete samples. In addition to their overlapping with each other, the results indicate the geopolymer concrete superiority over the regular concrete. Besides, it demonstrated the positive influence of nano-silica addition on the concert microstructure.

Influence of Fiber Content and Dosing Position on the the Mechanical Properties of Short-Carbon-Fiber Polypropylene Compounds.

The properties of short-fiber-reinforced composites depend on the fiber length of the reinforcing fibers. This fiber length is typically influenced by processing to different extents. In this work, we investigate the influence of processing, i.e., the influence of residence time achieved via different dosing points in compounding, and the fiber content on the fiber length and mechanical properties of short-carbon-fiber-reinforced polypropylene. We found that, with increasing fiber content, the fiber length decreases from 900 to 300 µm after compounding and from 500 to 250 µm after injection molding. Additionally, a decrease in residence time in the compounder leads to an increase in the fiber length of approx. 300 µm compared to the longer residence time. This is later reduced by the injection molding step, but the longer fibers are still longer in the final molded test specimen, thus resulting in a 5-10% increased tensile strength and elastic modulus as well as an some increase in impact strength. As the injection molding step showed considerable fiber length reduction (down to 250 µm), further investigations of injection molding should be undertaken to preserve fiber length better for the increased performance of these composites.

Digital experiment as a method for improving the mechanical properties of Hadfield steel

This study is devoted to determining the optimal composition of high-manganese austenitic Hadfield steel for producing castings with increased impact strength and hardness relative to the standard grade. The chemical composition of the steel was modified in terms of expanding the range of Mn content (12–19 %). The effect of combined doping with a complex of elements Cr, Mo, Ni is considered. Preliminary computer modeling and porosity analysis of the cast billets was carried out to determine the place of cutout of representative samples needed to evaluate the actual chemical composition and mechanical properties. Statistical analysis of the obtained results on the content of elements and impact strength of the samples was performed using the desirability function. Further optimization of the model was carried out using the response surface methodology. Based on the analysis of pairwise interactions, two experimental compositions of the Hadfield steel are proposed. A comparison of grade 110G13L with the proposed compositions based on the level of mechanical properties and grain score by microstructure is given. It is concluded that it is promising to further use the proposed Fe–1.1C–16Mn–0.8Si–1.3Cr–Ni–Mo composition, which can improve the reliability of castings operating under conditions of significant wear.The work was carried out within the framework of the state task for science of the Siberian Federal University, project number FSRZ-2020-0013.

Biomass-derived polyphosphazene toward simultaneously enhancing the flame retardancy and mechanical properties of epoxy resins

As one of the most widely used polymers, the intrinsic brittleness and high flammability bring about a stringent requirement for the practical application of epoxy resins (EPs). It is difficult to toughen EP without compromising its mechanical and thermal properties for many conventional toughening agents. Here, a novel furan-derived bio-based polyphosphazene (PFMP) with a flexible backbone and rigid side groups was prepared by the nucleophilic substitution reaction between polydichlorophosphazene (PDCP) and furfuralcohol. The resultant PFMP was incorporated into EP to realize exceptional toughening, strengthening, and flame retardant function. By adding 15% of PFMP, the limit oxygen index value is from 25% (EP) to 33% (EP/PFMP-15) and reaches the UL-94 V-0 rating. According to the cone calorimeter results, EP/PFMP-15 exhibits exceedingly reduced peak heat release rate (pHRR) (50.2%) and total heat release (THR) (49.6%). The significantly increased fire performance index (FPI) and decreased fire growth rate index (FIGRA) of EP/PFMP-15 demonstrate an improvement in its flame retardancy. The catalytic carbonization effect (condensed phase) and radical quenching effect (gas phase) of PFMP account for the greatly improved flame retardancy. Moreover, the impact and tensile tests indicate that PFMP can ameliorate the mechanical performance of EP with a maximum increase of impact strength (111.8%) and elongation at break (35.2%) for EP/PFMP-5. With 15% PFMP added, the tensile strength of EP/PFMP-15 increases by 40.4%. This work demonstrates that PFMP is expected to overcome shortcomings (flammability, toughness, and strength) of EP and spread its applied fields.

Phosphazene-Containing Epoxy Resins Based on Bisphenol F with Enhanced Heat Resistance and Mechanical Properties: Synthesis and Properties.

Organophosphazenes are of interest due to the combination of increased mechanical and thermal properties of polymer materials obtained with their use, however, they are characterized by a complex multi-stage synthesis. Moreover, the high viscosity of phosphazene-containing epoxy resins (PhER) makes their processing difficult. To simplify the synthesis of PhER, a one-step method was developed, and bisphenol F was chosen, which also provided a decrease in viscosity. In the current study, PhER were formed by a one-stage interaction of hexachlorocyclotriphosphazene (HCP) with bisphenol F isomers and epichlorohydrin in the presence of alkali, which was a mixture of epoxycyclophosphazenes (ECPh) with a functionality from 1 to 4 according to the results of MALDI-TOF analysis. Conventional epoxy resins based on bisphenol F, also formed during the process, showed high mechanical properties and glass transition temperature, and the reactivity of the obtained resins is similar to the base epoxy resins based on bisphenols A and F. Cured PhER had higher or the same mechanical properties compared to base epoxy resins based on bisphenol A and F, and a glass transition temperature comparable to base epoxy resins based on bisphenol F: glass transition temperature (Tg) up to 174.5 °C, tensile strength up to 74.5 MPa, tensile modulus up to 2050 MPa, tensile elongation at break up to 6.22%, flexural strength up to 146.6 MPa, flexural modulus up to 3630 MPa, flexural elongation at break up to 9.15%, and Izod impact strength up to 4.01 kJ/m2. Analysis of the composition of the obtained PhER was carried out by 1H and 31P NMR spectroscopy, MALDI-TOF mass spectrometry, X-ray fluorescence elemental analysis, and contained up to 3.9% phosphorus and from 1.3% to 4.2% chlorine. The temperature profile of the viscosity of the resulting epoxy resins was determined, and the viscosity at 25 °C ranged from 20,000 to 450,000 Pa·s, depending on the ratio of reagents. The resins studied in this work can be cured with conventional curing agents and, with a low content of the phosphazene fraction, can act as modifiers for traditional epoxy resins, being compatible with them, to increase impact strength and elasticity while maintaining the rest of the main mechanical and processing properties, and can be used as a resin component for composite materials, adhesives, and paints.

Improvement of mechanical properties of recycled PET by reactive toughening and post-crystallization

Noticeable increase in impact strength of recycled PET (RPET) was achieved using ethylene-butyl acrylate-glycidyl methacrylate (EBA-GMA) type reactive terpolymer (PTW). The decrease in stiffness and heat resistance due to reactive toughening was successfully compensated by thermal annealing. Based on the results, strong correlation can be shown between crystallinity and impact strength: increasing crystallinity results in reduced impact resistance at PTW contents higher than 5 m/m%, yet a 6-time increase compared to 100 % crystallized RPET was reached with 15 m/m% PTW content. Regarding heat resistance and stiffness, crystallinity appears to be the key parameter: above a critical value of 10 % crystallinity a sharp improvement of the properties can be noticed. Based on the results, properly choosing the elastomer ratio and post-crystallization conditions, post-consumer PET can be suitable for durable engineering applications as well.

Investigation of Impact Resistance of High-Strength Portland Cement Concrete Containing Steel Fibers.

Impact resistance of Portland cement concrete (PCC) is an essential property in various applications of PCC, such as industrial floors, hydraulic structures, and explosion-proof structures. Steel-fiber-fortified high-strength concrete testing was completed using a drop-weight impact assessment for impact strength. One mix was used to manufacture 320 concrete disc specimens cured in both humid and dry conditions. In addition, 30 cubic and 30 cylindrical specimens were used to evaluate the compressive and indirect tensile strengths. Steel fibers with hooked ends of lengths of 20, 30, and 50 mm were used in the concrete mixtures. Data on material strength were collected from impact testing, including the number of post-first-crack blows (INPBs), first-crack strength, and failure strength. Findings from the results concluded that all the steel fibers improved the mechanical properties of concrete. However, hooked steel fibers were more effective than crimped steel fibers in increasing impact strength, even with a smaller length-to-diameter ratio. Concrete samples containing hybrid fibers (hooked + crimped) also had lower compressive strength than the other fibers. Comparisons and analogies drawn between the test results and the static analyses (Kolmogorov–Smirnov and Kruskal–Wallis) show that the p-value of the analyses indicates a more normal distribution for curing in a humid environment. A significant difference was also observed between the energy absorptions of the reinforced mixtures into steel fibers.

Effects of blending poly(lactic acid) and thermoplastic polyester polyurethanes on the mechanical and adhesive properties in two-component injection molding

Abstract One possible way to increase the use of bioplastics and thus contribute to a more resource-efficient and sustainable economy is to broaden the application range of such bioplastics. Poly(lactic acid) (PLA) is a promising and commercially available bio-based and biologically degradable polymer, which exhibits a high strength and stiffness but is very brittle. Blending with other polymers can lead to an enhancement of the ductility of the PLA. The goal of this work was to show that blending of PLA with a bio-based thermoplastic polyester-urethane elastomer (TPU) increases the ductility of the compound and also affects the adhesion of the layers when the materials – the modified PLA compound and the TPU – are processed via two-component (2C) injection molding to form corresponding composite parts. The results show that both goals – the increased ductility as well as the increased adhesion between the polymeric phases in 2C parts – can be reached by compounding PLA with two different bio-based polyester-based TPUs. Tensile strength and Young’s modulus of the compounds decrease according to a linear mixing rule with the addition of TPU. Elongation at break and notched Charpy impact strength increase by 750 and 200%, respectively. By addition of the TPU, the surface free energies of the compounds were increased, especially the polar parts. This led to reduced interfacial tensions between the produced compounds and the neat TPUs and thus increased the adhesion between them. For the softer TPU the adhesion was so strong that the TPU showed a cohesive failure in the 90° peel test and thus could not be separated from the compound substrate at all. For the harder TPU the bonding strength increased by 140% upon the addition of this TPU inside the hard component.

An easy-to-implement self-healing smart design for increasing impact strength and crashworthiness resistance of honeycomb sandwich structures

In this paper, the dynamic compression impact response of an aluminum honeycomb core filled with open-cell foams impregnated with self-healing liquid agents was investigated experimentally. Samples were subjected to a variety of impacts in order to determine healing time and self-healing performance. Three different sandwich specimens were developed to evaluate the effectiveness of self-healing. The sandwich specimens are designated as B (empty honeycomb core cells), S (only open-cell soft polyurethane foam-filled honeycomb core cells), and self-healing agent (SHA) (open-cell soft polyurethane foams impregnated with liquid self-healing agents). The test results were presented by considering the crashworthiness and healing efficiency criteria, and the impact characteristics of the samples were compared related to these criteria. After testing, the results demonstrated that the self-healing agent specimens had much fewer buckling deformation and displacement than their counterparts. Significant improvements were achieved in healing efficiencies and crashworthiness evaluation criteria. The peak load and the energy needed to attain peak load are considered healing efficiency criteria. Self-healing agent specimens reached 29.7% and 12.9% more peak loads, and in the energy absorbed up to peak loads 140% and 34.9% higher values than the B and S sandwiches. In the same samples, crushing strain features were acquired as 50% versus 66%, indicating less displacement in self-healing agent specimens than counterparts. The results indicated that an aluminum honeycomb sandwich structure that can heal itself after damage and recover impact characteristics remarkably could be produced practically.

Experimental Investigation on the Mechanical Properties of Hybrid Composites Made with Banyan and Peepal Fibers

ABSTRACT Industries demand a material with better strength and light weight for various applications. Natural composites are fulfilling the needs of industries partially. The purpose of the present research is to develop a new composite material with light weight and better strength. In this research, hybrid composites were fabricated by conventional hand layup method using natural fibers such as banyan and peepal. Totally, four composites were manufactured namely banyan (Epoxy: banyan: 70 wt%: 30 wt %), peepal (Epoxy: peepal: 70 wt%: 30 wt %), BPB (Epoxy: banyan: peepal: 70 wt%: 20 wt%: 10 wt %) and PBP (Epoxy: banyan: peepal: 70 wt%: 10 wt%: 20 wt %). Density and porosity of the composites were determined and the results showed that BPB composite exhibited a least density. Further, all the composites displayed the maximum porosity percentage of 5. Moreover, the mechanical properties like tensile, flexural and impact strengths were tested. The hybrid composite BPB showed 2.7%, 4.9% and 13.5% increase in tensile, flexural and impact strength respectively, compared to PBP composite. Furthermore, water absorption study was conducted and the results revealed that BPB composite absorbed less amount of water (9%) at the immersion time of 12 hours. Hence, it is suggested from the present investigation that the BPB hybrid composite could be a suitable candidate for the industrial applications with better mechanical properties and light weight.

Continuous Fiber-Reinforced Material Extrusion with Hybrid Composites of Carbon and Aramid Fibers

An existing challenge in the use of continuous fiber reinforcements in additively manufactured parts is the limited availability of suitable fiber materials. This leads to a reduced adaptability of the mechanical properties to the load case. The increased design freedom of additive manufacturing allows the flexible deposition of fiber strands at defined positions, so that even different fiber materials can be easily combined in a printed part. In this work, therefore, an approach is taken to combine carbon and aramid fibers in printed composite parts to investigate their effects on mechanical properties. For this purpose, tensile, flexural and impact tests were performed on printed composite parts made of carbon and aramid fibers in a nylon matrix with five different mixing ratios. The tests showed that the use of hybrid composites for additive manufacturing is a reasonable approach to adapt the mechanical properties to the loading case at hand. The experiments showed that increasing the aramid fiber content resulted in an increase in impact strength, but a decrease in tensile and flexural strength and a decrease in stiffness. Microstructural investigations of the fracture surfaces showed that debonding and delamination were the main failure mechanisms. Finally, Rule of Hybrid Mixture equations were applied to predict the mechanical properties at different mixture ratios. This resulted in predicted values that differed from the experimentally determined values by an average of 5.6%.

Mechanical Performance Study of Kenaf/HDPE Composite for Structural Applications under Wet or Outdoor Environments

ABSTRACT The present work used natural fiber-reinforced polymer composite to explore its feasibility for structural applications in wet or outdoor environments. A novel technique of microwave-assisted compression molding (MACM) is used to manufacture kenaf/high-density polyethylene (HDPE) composites. Mechanical performance of 30 wt.% reinforced kenaf/HDPE composite conditioned in different environments for 6 months was evaluated. The liquids taken for environmental conditioning were sea water, 5% NaOH solution, deionized water, vegetable oil (soybean oil), and diesel. Mechanical performances were investigated and correlated with different attributes, i.e. wettability, liquid uptake, thickness swelling, absorption mechanism, and morphologies. It was observed that the tensile, flexural, and hardness properties were decreased due to degradation in interfacial bonding. Whereas increased impact strength was observed due to the plasticization effect after conditioning. Composites conditioned in vegetable oil retained highest value of physical and mechanical properties. Whereas composites conditioned in 5% NaOH solution followed by other conditioning environments showed maximum degradation in the properties. It can be inferred from the study that kenaf/HDPE composites can be used for medium load structural applications present in viscous and chemically neutral environments. The best-suited example of the present work is container for storage of vegetable oil and for making boundaries outside the property.

Potency of Banana (<i>Musa acuminata Linn.</i>) Stem Fiber as a Reinforcement Material for Heat Cured Acrylic Resin

Denture base made of heat-cured acrylic resin can be sometimes fractured easily during impact such as falling while cleaning it. This study aimed to evaluate the impact strength of heat-cured acrylic resin added with banana (Musa acuminata Linn.) stem fiber of 0.5%, 1%, 1.5% by weight. A total of 32 plate-shaped specimens of heat-cured acrylic resin measuring 65 x 10 x 2.5 mm were divided into 4 groups, group I as control (without addition of banana stem fiber), group II (with addition of 0.5% banana stem fiber), group III (with addition of 1% banana stem fiber), and group IV (with addition of 1.5% banana stem fiber), then the impact strength test was performed using a Charpy Impact Tester. The result shows that the impact strength were increased from group I to group IV and the data obtained were analyzed statistically using One Way ANOVA and post hoc LSD test (p <0.05). The data showed significantly results of the impact strength value with group IV as the highest among all groups, and an increase in impact strength occurred along with increase in the percentage of fiber added to the heat-cured acrylic resin. Based on the results, banana stem fiber has the potential as heat cured acrylic resin reinforcement materials.

Using Cellulose-graft-Poly(L-lactide) Copolymers as Effective Compatibilizers for the Preparation of Cellulose/Poly(L-lactide) Composites with Enhanced Interfacial Compatibility.

Cellulose-grafte-poly(L-lactide) (C-g-PLLA) copolymers synthesized in a CO2-switchable solvent are proposed for use as effective compatibilizers for the preparation of cellulose–PLLA composites with enhanced interfacial compatibility. The effect of the molar substitution (MSPLLA) of the grafted PLLA side chain in the C-g-PLLA copolymer and the feeding amount of this copolymer on the mechanical and thermal properties and hydrophilicity of the composites was investigated. The composites had a largely increased impact strength with the incorporation of the compatibilizer. With the increasing of MSPLLA and the feeding amount of the copolymer, the resulting composites had an increased impact strength. When 5 wt% C-g-PLLA with MSPLLA of 4.46 was used as a compatibilizer, the obtained composite containing 20 wt% cellulose presented an impact strength equal to that obtained for the neat PLLA. The composites had a slightly decreased melting temperature and thermal decomposition temperature, but increased hydrophilicity due to the incorporation of the compatibilizer. This work suggests an effective method to improve the interfacial compatibility between cellulose and PLLA for the fabrication of fully bio-based composites with high performance.