An investigation on the rheology,morphology, thermal and mechanical properties of recycled poly (ethylene terephthalate) reinforced with modified short glass fibers

This work was done with the aim to solve an important environmental issue regarding poly (ethylene terephthalate), (PET) wastes. Samples of recycled PET (r-PET) were reinforced with 10 to 30 wt% modified short glass fibers (SGF) through a melt mixing process in an internal mixer and their performance were assessed and compared with those of commercial glass reinforced PET through investigation of their rheology, morphology, thermal, and mechanical properties. It was found that the mechanical properties of the glass reinforced r-PET composites in most cases were comparable or even higher than those of the commercial grades. The impact strength of the 30 wt% SGF filled r-PET composite was about 30% higher than the commercial grades. This led to a conclusion that the PET wastes can be successfully converted to easily moldable thermoplastic materials by incorporation of 30 wt% SGF having a good balance of properties. Through investigation of rheological and morphological properties the optimum conditions for the best reinforcement performance were determined. The r-PET with 30 wt% glass fiber content showed the highest level of orientation and improved interaction with the r-PET matrix while having an acceptable flow behavior and processability. In spite of significant fiber breakage during the melt mixing process, leading to about 20 times reduction in the fiber aspect ratio, the composites maintained their good mechanical properties and showed a shear thinning behavior at high shear rates. The incorporated glass fibers acted as nucleating agents and improved the crystallization rate of r-PET leading to an overall increase in the crystallinity. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Unsaturated polyester‐toughened epoxy composites: Effect of sisal fiber on thermal and dynamic mechanical properties

In the present study, the mechanical and thermal properties of sisal fiber‐reinforced unsaturated polyester (UP)‐toughened epoxy composites were investigated. The sisal fibers were chemically treated with alkali (NaOH) and silane solutions in order to improve the interfacial interaction between fibers and matrix. The chemical composition of resins and fibers was identified by using Fourier‐transform infrared spectroscopy. The UP‐toughened epoxy blends were obtained by mixing UP (5, 10, and 15 wt%) into the epoxy resin. The fiber‐reinforced composites were prepared by incorporating sisal fibers (10, 20, and 30 wt%) within the optimized UP‐toughened epoxy blend. Scanning electron microscopy was used to analyze the morphological changes of the fibers and the adhesion between the fibers and the UP‐toughened epoxy system. The results showed that the tensile and flexural strength of (alkali‐silane)‐treated fiber (30 wt%) ‐reinforced composites increased by 83% and 55%, respectively, as compared with that of UP‐toughened epoxy blend. Moreover, thermogravimetric analysis revealed that the (alkali‐silane)‐treated fiber and its composite exhibited higher thermal stability than the untreated and alkali‐treated fiber systems. An increase in storage modulus and glass transition temperature was observed for the UP‐toughened epoxy matrix on reinforcement with treated fibers. The water uptake behavior of both alkali and alkali‐silane‐treated fiber‐reinforced composites is found to be less as compared with the untreated fiber‐reinforced composite. J. VINYL ADDIT. TECHNOL., 23:188–199, 2017. © 2015 Society of Plastics Engineers     

Polyamide‐6 composites reinforced with cellulose fibers and fabricated by extrusion: Effect of fiber bleaching on mechanical properties and stability

We prepared polyamide‐6 (PA‐6) composites using bleached and semibleached cellulose fibers from Eucalyptus species by processing in a corotating interpenetrating twin‐screw extruder. PA‐6 is a challenging matrix because of its high processing temperature, which overlaps the thermodegradation temperature of the fibers. The selection of the processing conditions for extrusion and the use of the lubricant ethylene bis (stearamide) permitted the production of composites with 20, 30, and 40 wt% of bleached fibers, which are lighter than the corresponding glass fiber composites. Composites with 30 wt% of bleached fibers yield the best mechanical properties and good fiber/matrix interaction, as demonstrated by mechanical tests and scanning electron microscopy. X‐ray photoelectron spectroscopy studies showed that the natural moisture in the fibers promotes the fiber/matrix interaction through the formation of ester bonds. We assessed the effect caused by the presence of lignin in the fibers. Composites containing 30 wt% of semibleached fibers maintained the flexural properties and showed small improvements in thermal stability when compared with bleached fiber composites; however, there is a slight decrease in the tensile properties. Through accelerated aging tests, we observed that increased lignin concentration in the fibers reduced the formation of carbonyl compounds on sample surfaces, indicating a stabilization effect. POLYM. COMPOS., 38:299–308, 2017. © 2015 Society of Plastics Engineers     

Influence of interfacial adhesion on the structural and mechanical behavior of PP‐banana/glass hybrid composites

Hybrid composites of polypropylene (PP), reinforced with short banana and glass fibers were fabricated using Haake torque rheocord followed by compression molding with and without the presence maleic anhydride grafted polypropylene (MAPP) as a coupling agent. Incorporation of both fibers into PP matrix resulted in increase of tensile strength, flexural strength, and impact strength upto 30 wt% with an optimum strength observed at 2 wt% MAPP treated 15 wt% banana and 15 wt% glass fiber. The rate of water absorption for the hybrid composites was decreased due to the presence of glass fiber and coupling agent. The effect of fiber loading in presence of coupling agent on the dynamic mechanical properties has been analyzed to investigate the interfacial properties. An increase in storage modulus (E′) of the treated‐composite indicates higher stiffness. The loss tangent (tan δ) spectra confirms a strong influence of fiber loading and coupling agent concentration on the α and β relaxation process of PP. The nature of fiber matrix adhesion was examined through scanning electron microscopy (SEM) of the tensile fractured specimen. Thermal measurements were carried out through differential scanning calorimetry (DSC) and the thermogravimetric analysis (TGA), indicated an increase in the crystallization temperature and thermal stability of PP with the incorporation of MAPP‐treated banana and glass fiber. POLYM. COMPOS., 31:1247–1257, 2010. © 2009 Society of Plastics Engineers     

Influence of different glass fiber sizings on selected mechanical properties of PET/glass composites

The properties of fiber-reinforced plastics are considerably influenced by fiber-matrix interaction. The aim of this study was to investigate the influence of glass fiber surface treatments on the morphology of poly(ethylene terephthalate) (PET) and on selected mechanical properties of unidirectional PET/glass fiber composites. The materials used here were E-glass fibers treated with model sizings including aminosilane as a coupling agent and polyurethane and epoxy resin dispersions as film formers and PET as the matrix. For identification of the degree of crystallinity of the PET matrix, differential scanning calorimetry (DSC) was used. To study the influence of the different sizings on the mechanical properties, the following tests were performed: interlaminar and intralaminar shear tests and a transverse tensile test. Dynamic-mechanical analysis (DMA) was used to characterize the behavior of the composites under dynamical load. The DSC results show that the overall crystallinity and the melting behavior of the PET matrix were hardly influenced by the glass fiber surface treatments used. The various strength properties of the composites are influenced not only by the silane coupling agent, but also by the type of film former. With an epoxy resin dispersion, the mechanical properties were enhanced compared with a polyurethane dispersion. These results were confirmed by characterization of the composites by DMA.     

Relationship between processing method and microstructural and mechanical properties of poly(ethylene terephthalate)/short glass fiber composites

Composites of recycled poly(ethylene terephthalate) (PET) reinforced with short glass fiber (GF) (0, 20, 30, and 40 wt %) were compounded in a single‐screw extruder (SSE) and in a intermeshing corotating twin‐screw extruder (TSE). An SSE fitted with a barrier double‐flight screw melting section in between two single‐flight sections and a TSE with a typical screw configuration for this purpose were used. The composites were subsequently injection molded at two different mold temperatures (10 and 120°C), with all other operative molding parameters kept constant. The effects of processing conditions on composite microstructure, PET degree of crystallinity, and composite mechanical properties were evaluated. Appropriate dispersive and distributive mixing of the glass fiber throughout the PET matrix as well as fine composite mechanical and thermal‐mechanical properties were achieved regardless of whether the composites were prepared in the SSE or TSE. The performance of the SSE was attributed to the efficiency of the barrier screw melting section in composite mixing. The mold temperature influenced the mechanical properties of the composites, by controlling of the degree of crystallinity of the PET in the composites. For a good balance of mechanical and thermal‐mechanical properties, high mold temperatures are desirable, typically, 120°C for a mold cooling time of 45 s. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Preparation and properties of hierarchical composites based on carbon nanotubes‐coated glass babric preform

A strategy based on carbon nanotubes (CNTs)‐containing sizing dispersion has been implemented to fabricate nanocomposite preforms and their hybrid multiscale composites. The state of pristine CNTs and carboxylic acid functionalized CNTs (CNTs–COOH) in sizing dispersion was effectively monitored by on‐line measuring electrical conductivity. The effects of different CNTs coating applied onto glass fabric on wettability of nanocomposite fibrous reinforcement with epoxy matrix were evaluated using scanning electron microscopy and capillary experiment. A CNTs‐COOH loading of 0.5 wt% gave rise to 97% and 30°C increases in the storage modulus (G′) and glass transition temperature of the resulting hybrid composites, respectively. The enhanced thermomechanical properties of the CNTs hybrid composites are closely related to the stable CNTs sizing dispersion and uniform coating onto fiber reinforcement. The mechanism for reinforcing composites through toughening resin region with CNTs desorbing from primary fiber surface during impregnation has been identified. POLYM. COMPOS. 37:979–986, 2016. © 2014 Society of Plastics Engineers     

An investigation for the effect of recycled matrix on the properties of textile waste cotton fiber reinforced (T‐FRP) composites

The main objective of this research is to study the effect of recycled low density polyethylene (r‐LDPE) matrix on the tensile, impact, and flexural properties of the novel textile waste cotton fiber reinforced (T‐FRP) composites. For this purpose, the T‐FRP composites were manufactured by using two different matrix types; namely, virgin LPDE (v‐LDPE) and r‐LDPE, with different waste cotton fiber content. All composites were compatibilized by maleic anhydride‐LDPE (MA‐LDPE) in order to increase the interfacial adhesion between fibers and matrices. Differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, dynamic mechanical analyzer studies were performed in order to characterize the materials. The results have shown that best tensile and flexural properties have been obtained from the composites with the content of 30 wt% cotton fiber, 5 wt% maleic anhydride‐LDPE, and 65 wt% recycled LDPE matrix. However, the impact properties of the composites were decreased drastically compared to the pure LDPE matrix. POLYM. COMPOS., 38:1231–1240, 2017. © 2015 Society of Plastics Engineers     

Short glass fiber reinforced ABS and ABS/PA6 composites: Processing and characterization

In this study acrylonitrile‐butadiene‐styrene (ABS) terpolymer was reinforced with 3‐aminopropyltrimethoxysilane (APS)‐treated short glass fibers (SGFs). The effects of SGF concentration and extrusion process conditions, such as the screw speed and barrel temperature profile, on the mechanical properties of the composites were examined. Increasing the SGF concentration in the ABS matrix from 10 wt% to 30 wt% resulted in improved tensile strength, tensile modulus and flexural modulus, but drastically lowered the strain‐at‐break and the impact strength. The average fiber length decreased when the concentration of glass fibers increased. The increase in screw speed decreased the average fiber length, and therefore the tensile strength, tensile modulus, flexural modulus, and impact strength were affected negatively and the strain‐at‐break was affected positively. The increase in extrusion temperature decreased the fiber length degradation, and therefore the tensile strength, tensile modulus, flexural modulus, and impact strength increased. At higher temperatures the ABS matrix degraded and the mechanical strength of the composites decreased. To obtain a strong interaction at the interface, polyamide‐6 (PA6) at varying concentrations was introduced into the ABS/30 wt% SGF composite. The incorporation and increasing amount of PA6 in the composites broadened the fiber length distribution (FLD) owing to the low melt viscosity of PA6. Tensile strength, tensile modulus, flexural modulus, and impact strength values increased with an increase in the PA6 content of the ABS/PA6/SGF systems due to the improved adhesion at the interface, which was confirmed by the ratio of tensile strength to flexural strength as an adhesion parameter. These results were also supported by scanning electron micrographs of the ABS/PA6/SGF composites, which exhibited an improved adhesion between the SGFs and the ABS/PA6 matrix. POLYM. COMPOS. 26:745–755, 2005. © 2005 Society of Plastics Engineers     

Bamboo fiber polypropylene composites: Effect of fiber treatment and nano clay on mechanical and thermal properties

In the current study, bamboo fibers were modified with sodium meta‐periodate in order to improve the mechanical and thermal properties of the bamboo‐clay‐polypropylene (PP) composites. Both raw and treated bamboo fibers were used in the manufacturing of the composites. The mechanical and thermal properties of the composites from modified bamboo fibers were found to increase considerably compared with those of untreated fibers. Tensile strengths of (raw bamboo fiber)/PP, (raw bamboo fiber‐clay)/PP, and (treated bamboo fiber‐clay)/PP composites showed a decreasing trend with increasing fiber loadings. However, the values for the chemically modified (bamboo fiber)‐clay‐PP composite at all mixing ratios were found to be higher than that of the original PP. The scanning electron micrographs showed that interfacial bonding between the treated fiber‐clay and matrix has significantly improved. It was determined that better dispersion of the filler into matrix occurred on 5% clay addition and fiber treatment. J. VINYL ADDIT. TECHNOL., 21:253–258, 2015. © 2014 Society of Plastics Engineers     

Mechanical,thermal and dynamic‐mechanical behavior of banana fiber reinforced polypropylene nanocomposites

Natural fiber‐reinforced nanocomposites based on polypropylene/nanoclay/banana fibers were fabricated by melt mixing in a twin‐screw extruder followed by compression molding in this current study. Maleic anhydride polypropylene copolymer (MA‐g‐PP) was used as a compatibilizer to increase the compatibility between the PP matrix, clay, and banana fiber to enhance exfoliation of organoclay and dispersion of fibers into the polymer matrix. Variation in mechanical, thermal, and physico‐mechanical properties with the addition of banana fiber into the PP nanocomposites was investigated. It was observed that 3 wt% of nanoclay and 5 wt% of MA‐g‐PP within PP matrix resulted in an increase in tensile and flexural strength by 41.3% and 45.6% as compared with virgin PP. Further, incorporation of 30 wt% banana fiber in PP nanocomposites system increases the tensile and flexural strength to the tune of 27.1% and 15.8%, respectively. The morphology of fiber reinforced PP nanocomposites has been examined by using scanning electron microscopy and transmission electron microscopy. Significant enhancement in the thermal stability of nanocomposites was also observed due to the presence of nanoclay under thermogravimetric analysis. Dynamic mechanical analysis tests revealed an increase in storage modulus (E′) and damping factor (tan δ), conforming the strong interaction between nanoclay/banana fiberand MA‐g‐PP in the fiber‐reinforced nanocomposites systems. POLYM. COMPOS., © 2011 Society of Plastics Engineers.     

Banana/Glass Fiber-Reinforced Polypropylene Hybrid Composites: Fabrication and Performance Evaluation

Hybrid composites of Polypropylene (PP) reinforced with intimately mixed short banana and glass fibers were fabricated using Haake twin screw extruder followed by compression molding with and without the presence maleic anhydride grafted polypropylene (MAPP) as a coupling agent. Incorporation of both the fibers into PP matrix resulted in an increase in tensile, flexural and impact strength with an increasing level of fiber content upto 30 wt% at banana: glass fiber ratio of 15:15 wt% and 2 wt% of MAPP. The rate of water absorption for the hybrid composites decreased due to the presence of glass fiber and coupling agent. The effect of fiber loading in presence of coupling agent on the dynamic mechanical properties has also been analyzed to investigate the interfacial properties. An increase in the storage modulus (E′) of the treated composite indicates higher stiffness. The tan δ spectra confirms a strong influence of fiber contents and coupling agent on the α and β relaxation processes of PP. The nature of fiber matrix adhesion was examined through scanning electron microscopy (SEM) of the tensile fractured specimen. Thermal measurements were carried out employing differential scanning calorimetry (DSC) and the thermogravimetric analysis (TGA) which indicated a decrease in the crystallization temperature and thermal stability of PP with the incorporation of MAPP treated banana and Glass fiber.     

Characterization of nanocomposite laminates fabricated from aqueous dispersion of nanoclay

Preparation of E‐glass/waterborne epoxy prepregs containing natural nanoclay and properties of their composites are presented. Prepregs were prepared by wetting randomly oriented, chopped glass fiber preforms with aqueous dispersion of EpiRez 3522‐W‐60 resin, dicyandiamide, 2‐methylimidazole and natural nanoclay (Cloisite® Na⁺). The nanoclay content of the aqueous dispersion was adjusted to yield final nanoclay contents of 0, 1, 2, and 4 wt%, whereas the glass fiber content is kept constant at 47 wt%. These prepregs were then used to fabricate disk‐shaped composite samples by APA2000 rheometer. Composite samples were tested for interlaminar shear strength, flexural stiffness, and glass transition temperature. The flexural stiffness was observed to increase by more than 26% over the range of nanoclay loading, despite a 13% decrease in interlaminar shear strength. Similarly, glass transition temperature increased from 89°C to above 94°C for the samples comprising 4 wt% nanoclay. X‐ray diffraction analyses indicated 48% increase in the gallery spacing suggesting strong intercalation of the nanoclay platelets by the epoxy matrix. Microstructural observations of the fracture surfaces and polished surfaces show significant differences in the matrix topology and fiber to matrix adhesion. The composites with higher nanoclay content depict uniform and submicron surface features implying homogenous dispersion of nanoclay. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

Concentration effect of γ‐glycidoxypropyltrimethoxysilane on the mechanical properties of glass fiber–epoxy composites

In this study, glass fibers were modified using γ‐glycidoxypropyltrimethoxysilane of different concentrations to improve the interfacial adhesion at interfaces between fibers and matrix. Effects of γ‐glycidoxypropyltrimethoxysilane on mechanical properties and fracture behavior of glass fiber/epoxy composites were investigated experimentally. Mechanical properties of the composites have been investigated by tensile tests, short beam tests, and flexural tests. The short‐beam method was used to measure the interlaminar shear strength (ILSS) of laminates. The tensile and flexural properties of composites were characterized by tensile and three‐point bending tests, respectively. The fracture surfaces of the composites were observed with a scanning electron microscope. On comparing the results obtained for the different concentrations of silane solution, it was found that the 0.5% GPS silane treatment provided the best mechanical properties. The ILSS value of heat‐cleaned glass fiber reinforced composite is enhanced by ∼59% as a result of the glass fiber treatment with 0.5% γ‐GPS. Also, an improvement of about 37% in tensile strength, about 78% in flexural strength of the composite with the 0.5% γ‐GPS treatment of glass fibers was observed. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Mechanical and Thermal Properties Modeling,Sorption Characteristics of Multiscale (Multiwalled Carbon Nanotubes/Glass Fiber) Filler Reinforced Polypropylene Composites

The present work was aimed to investigate the individual and hybrid reinforcement effect of multiscale fillers [glass fibers (GF)/multiwalled carbon nanotubes (MWCNTs)] in polypropylene (PP) matrix. The MWCNT content in the hybrid composites was varied from 0.5 to 5 wt%, and glass fiber fraction was fixed as 20 wt%. The morphology of nano and hybrid composite revealed reasonable dispersion of MWCNTs and glass fibers in the matrix. At a MWCNT content of 3 wt%, the optimum tensile properties for the hybrid composites were achieved and beyond which it declined due to agglomeration effects as revealed by transmission electron microscopy. A comparative study of the experimental and predicted values of moduli of nano, micro, and hybrid composites using various micromechanical models was conducted. The simultaneous incorporation of MWCNTs and glass fibers in PP restricted the mobility of polymer chains as indicated by the increase in storage modulus and rise in glass transition temperature obtained by dynamic mechanical analysis. The differential scanning calorimetry studies indicated that the inclusion of 2 wt% of MWCNTs increased the crystallinity of PP from 58.2 to 69.1% in hybrid composites. The Avrami and Mo models were used to explore nonisothermal crystallization kinetics, and Mo model was in close agreement with the experimental results. The sorption behavior of the composites revealed that the formation of immobilized regions developed by the simultaneous inclusion of micro and nano fillers delayed the transport of the solvent. J. VINYL ADDIT. TECHNOL., 25:E94–E107, 2019. © 2019 Society of Plastics Engineers     

Benefits of low kenaf loading in biobased composites of poly(L‐lactide) and kenaf fiber

Bast fibers from stems of kenaf (Hibiscus cannabinus, L.), a warm‐season tropical herbaceous annual plant, were dispersed into poly‐L ‐lactide (PLLA) matrix by melt‐mixing followed by compression molding. Low fiber fractions (1–5%) were investigated. The composites showed a slight lowering of thermal stability when evaluated by thermogravimentric analysis. X‐ray diffraction and differential scanning calorimetry indicated an influence of kenaf on the crystallization of PLLA. The fiber dispersion in the polymer matrix was established by polarized optical microscopy. Scanning electron microscopy showed good fiber–matrix adhesion as revealed by the combination of dispersion, interaction, and crystallinity, which enabled an increase in the mechanical properties of the composite that scaled with concentration. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Polymerization compounding composites of nylon‐6,6/short glass fiber

Nylon‐6,6 was grafted onto the surface of short glass fibers through the sequential reaction of adipoyl chloride and hexamethylenediamine onto the fiber surface. Grafted and unsized short glass fibers (USGF) were used to prepare composites with nylon‐6,6 via melt blending. The glass fibers were found to act as nucleating agents for the nylon‐6,6 matrix. Grafted glass fiber composites have higher crystallization temperatures than USGF composites, indicating that grafted nylon‐6,6 molecules further increase crystallization rate of composites. Grafted glass fiber composites were also found to have higher tensile strength, tensile modulus, dynamic storage modulus, and melt viscosity than USGF composites. Property enhancement is attributed to improved wetting and interactions between the nylon‐6,6 matrix and the modified surface of glass fibers, which is supported by scanning electron microscopy (SEM) analysis. The glass transition (tan δ) temperatures extracted from dynamic mechanical analysis (DMA) are found to be unchanged for USGF, while in the case of grafted glass fiber, tan δ increases with increasing glass fiber contents. Moreover, the peak values (i.e., intensity) of tan δ are slightly lower for grafted glass fiber composites than for USGF composites, further indicating improved interactions between the grafted glass fibers and nylon‐6,6 matrix. The Halpin‐Tsai and modified Kelly‐Tyson models were used to predict the tensile modulus and tensile strength, respectively.     

Experimental investigation on the influence of the composition on the morphology and the mechanical properties of short glass fiber‐reinforced polypropylene nanocomposites

Polypropylene composites containing 0–5 wt% layered silicate and 0–30 wt% short glass fibers are prepared by melt compounding. To investigate the influence of different compositions on the mechanical properties of short glass fiber‐reinforced polypropylene nanocomposites, materials with various filler contents are prepared. At a glass fiber content of 10 wt% Young's modulus of the layered silicate‐containing composites decreases by around 30% compared to conventional glass fiber‐reinforced polypropylene. But at higher glass fiber loadings, an increasing modulus of up to 10% is observed. However, the addition of layered silicate results in large decreases of the tensile and the notched impact strength. A maleic anhydride‐grafted polypropylene enhances Young's modulus and the tensile strength. © 2012 Society of Plastics Engineers     

Mechanical,thermal, and dynamic mechanical properties of long glass fiber‐reinforced thermoplastic polyurethane/polyoxymethylene composites

Long glass fiber (LGF)‐reinforced thermoplastic polyurethane (TPU) elastomers and polyoxymethylene (POM) (LGF/TPU/POM) composites were prepared by using self‐designed impregnation device. Dynamic mechanical properties of the LGF/TPU/POM composites have been investigated by using dynamic mechanical thermal analysis. The results indicated that the storage modulus and glass transition temperature of the composites increase with increasing the glass fibers content and scanning frequencies. In addition, the Arrhenius relationship has been used to calculate the activation energy of α‐transition of the LGF/TPU/POM composites. The thermal stability of the LGF/TPU/POM composites was investigated by thermogravimetric analysis. The consequence demonstrated that the thermal stability increase with augmenting the content of glass fibers. The mechanical properties of the composites are investigated by a universal testing machine and a ZBC‐4 Impact Pendulum. The results demonstrated the mechanical properties of the composites aggrandize with augmenting the glass fibers content. The good dispersion of the LGFs in the matrix resins is obtained from scanning electron micrographs. POLYM. COMPOS., 35:2067–2073, 2014. © 2014 Society of Plastics Engineers     

Development and study of fully biodegradable composite materials based on poly(butylene succinate) and hemp fibers or hemp shives

The use of natural fibers to reinforce polymers is an established practice, and biocomposites have gained an increased interest in areas such as automotive, construction, and agriculture. The purpose of the present work was the preparation and study of fully biodegradable (“green”) composite materials using poly(butylene succinate) (PBSu) as polymeric matrix and hemp fibers and shives as fillers. Composites containing 15, 30, 50, 60, and 70 wt% of fillers were prepared by melt mixing in a twin screw extruder. The composites were studied using Fourier transform infrared spectroscopy, X‐ray diffraction, and differential scanning calorimeter while the dispersion and interfacial adhesion were studied with scanning electron microscopy. From mechanical properties measurements, it was found that tensile and impact strength are both affected by the type and the amount of the used filler. The degree of crystallinity of PBSu was found to decrease by increasing the filler content, although that both fillers can act as nucleating agents. Finally, the degradation rate during enzymatic hydrolysis and soil burial increased in all biocomposites by increasing the filler content. PBSu/hemp shive composites showed higher biodegradation rates than PBSu/hemp fiber composites. POLYM. COMPOS., 37:407–421, 2016. © 2014 Society of Plastics Engineers