Crystallization, Morphology and Mechanical Properties of PLA/PBAT/CaCO3 Composites

2012 ◽  
Vol 602-604 ◽  
pp. 768-771 ◽  
Author(s):  
Nan Shi ◽  
Jun Cai ◽  
Qiang Dou

The melting, crystallization behavior, morphology and mechanical properties of poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT)/calcium carbonate (CaCO3) composites were investigated by means of differential scanning calorimetry (DSC), scanning electron microscopy(SEM), and mechanical test. It is shown that PBAT decreases the crystallinity, while CaCO3 increases the crystallinity of the composites. A synergistic toughening effect is obtained by the combination of CaCO3 and PBAT. The optimum mechanical properties can be achieved in case of the composite (PLA: PBAT: CaCO3=60: 20: 20).

2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.


2008 ◽  
Vol 575-578 ◽  
pp. 941-946
Author(s):  
Hong Yan Tang ◽  
Ji Hui Wang ◽  
Guo Qiang Gao ◽  
Wen Xing Chen

Fiberglass continuous strand mat(CSM)/poly(urethane-isocyanurate) composites were formed by SRIM process, treated under different conditions and then characterized based on dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) ,transmission electron microscopy (TEM) and the mechanical property tests. The results show that the mechanical properties of the composites could be increased with improving the degree of microphase separation. At a given temperature (120°C), the degree of microphase separation is the highest for 4h and decreases gradually with prolonging treatment time. For a given time (4h), the well microphase-separated morphology is obtained and the degree of microphase mixing is increased at 120°C and 140°C treatments, respectively. The degree of microphase separation of the composites decreases with enhancing the temperature to 140°C.


Author(s):  
Mohammad K. Hossain ◽  
Samira N. Shaily ◽  
Hadiya J. Harrigan ◽  
Terrie Mickens

A completely biodegradable composite was fabricated from an herbal polymer, soy protein concentrate (SPC) resin. Soy protein was modified by adding 30 wt% of glycerol and 5 wt% of poly vinyl alcohol (PVA) to enhance its mechanical as well as thermal property. 3%, 5%, 10%, and 20% nanoclay (NC) were infused into the system. To evaluate its mechanical properties, crystallinity, thermal properties, bonding interaction, and morphological evaluation, tensile, X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR) tests, and optical microscopy (OM) and scanning electron microscopy (SEM) evaluation were performed. Tensile tests showed that the addition of nanoclay improved the mechanical properties of the modified resin. Soy protein is hydrophilic due to the presence of amino acids that contain various polar groups such as amine, carboxyl, and hydroxyl. As a result, polar nanoclay particles that are exfoliated can be evenly dispersed in the SPC resin. From experimental results, it is clear that adding of nanoclay with SPC resin significantly increased the stiffness of the SPC resin. A combination of 5% clay, 30% glycerol, and 5% PVA with the modified SPC resulted in the maximum stress of 18 MPa and Young modulus of 958 MPa. The modified SPC showed a reduced failure strain as well. X-ray diffraction curves showed an improvement of crystallinity of the prepared resin with increasing amount of nanoclay. Interaction among soy, glycerol, PVA, and nanoclay was clearly demonstrated from the FTIR analysis. Optical microscopy (OM) and scanning electron microscopy (SEM) micrographs revealed rougher surface in the nanoclay infused SPC samples compared to that of the neat one. SEM evaluation revealed rougher fracture surface in the NC infused samples.


2020 ◽  
Vol 12 (10) ◽  
pp. 1558-1567
Author(s):  
Shengbin Li ◽  
Haoqian Ren ◽  
Qin Wu ◽  
Yiyang Ye

Magnesium oxysulfate cement is an ecological gas-hardening cementitious material. The cement has a complex system, insufficient hydration, and unstable hydration products, so that the cement mechanical property is poor. In this study, calcium chloride/carbon dioxide/weak buffer solution is used to generate alkaline additive, namely vaterite calcium carbonate. The additive material is characterized by scanning electron microscopy and X-ray diffraction, and then the optimal MgO/MgSO4/H2O molar ratio after calcium carbonate is added to magnesium oxysulfate cement, the optimal laying method and reasonable amount of vaterite calcium carbonate are analyzed by mechanical tests. In the experiment, the basic additive is characterized firstly. It is found that the XRD of the additive mainly includes the peaks of calcite and vaterite. It can be seen by scanning electron microscopy that many calcites and vaterites are not formed, the calcites are accumulated more, and there is a large number of particles, which are not appeared before. In the mechanical test of magnesium sulfide cement, the mechanical properties of magnesium oxysulfate cement will increase firstly and then decrease with the increase of MgO/MgSO4 molar ratio in the way of long-cut calcium carbonate for reinforcement. Compared with the layout of long-cut calcium carbonate-magnesium oxysulfate cement, the layout of short-cut calcium carbonate-magnesium oxysulfate cement can enhance the toughness of the modified cement, increase the amount of calcium carbonate, and improve the flexural strength and toughness index of the modified magnesium oxysulfate cement. The blending ratio is better to be 6%. Based on above researches and demonstrations, blending the calcium carbonate-based alkaline additive can effectively improve the mechanical properties of the magnesium oxysulfate cement.


2017 ◽  
Vol 264 ◽  
pp. 228-231
Author(s):  
Nasuha Marzuki ◽  
Muhamad Amirul Ashraf Mohd Alias ◽  
Arjulizan Rusli ◽  
Zulkifli Ahmad

A relatively new way to improve processibility thermoplastics is via the use of crosslinkable monomers which can act as reactive plasticizers and reduce the viscosity in the early stage of processing. The monomers can polymerize and phase separate during final stage of processing thus recovering the original thermoplastics properties. In this work, the applicability of epoxy as reactive plasticizer for polyetherimide (PEI) was investigated. The properties of PEI/epoxy blends without and with curative were studied in order to determine the effect of the monomer on the processibility of the PEI and the thermo-mechanical properties of cured blends. Differential Scanning Calorimetry on blends without curative indicated single glass transition temperature (Tg) at high PEI content suggesting miscibility of the system and plasticization of PEI in the presence of epoxy while cured blends indicated two Tg due to phase separation. Scanning electron microscopy of the cured blends indicated two phase morphology with PEI dispersed particles size increased in continuous epoxy matrix with increasing PEI (up to 30wt% PEI). In blends with 40wt% PEI and more, phase inverted morphology was observed where increasing PEI content caused reduction of epoxy particle size in continuous PEI matrix.


2016 ◽  
Vol 36 (6) ◽  
pp. 625-633 ◽  
Author(s):  
Jin Ding ◽  
Zhen Ming Yue ◽  
Jiao Sun ◽  
Ji Cui Zhou ◽  
Jun Gao

Abstract Acrylonitrile-butadienestyrene (ABS)/poly(methylmethacrylate) (PMMA)/ethylene methacrylate (EMA) composites were prepared with different blending sequences. All ABS/PMMA/EMA copolymers were designed to achieve the same total chemical composition, in which ABS/PMMA was equal to 80/20 and EMA was fixed at 6 wt%. The effects of different blending sequences on the mechanical and optical properties of ABS/PMMA/EMA blends were investigated. Results indicated that the tensile strengths of ABS/PMMA/EMA blends with different blending sequences were slightly affected, whereas the Izod impact strength of blends significantly varied. The impact toughness of the blends, in which PMMA/EMA was initially blended and then combined with ABS, was approximately twice that of the other blends. This blending sequence also had surface glossiness that was superior to those of the other blends. Differential scanning calorimetry and scanning electron microscopy further revealed that blending sequence influenced the phase miscibility and dispersion of the blends, which led to different mechanical and optical properties.


2021 ◽  
pp. 096739112110271
Author(s):  
Reyhaneh Fatahian ◽  
Mohammad Mirjalili ◽  
Ramin Khajavi ◽  
Mohammad Karim Rahimi ◽  
Navid Nasirizadeh

Differences in the properties of poly(vinyl alcohol) (PVA) and poly (lactic acid) (PLA) polymers have attracted much attention today. In this research, the aim is to produce PVA/PLA nanofibers with hydrophilicity and good mechanical properties using a mutual solvent. In this regard, the ability to produce PVA/PLA nanofibers using a mutual solvent was evaluated. The effect of electrospinning parameters on the morphology of nanofibers, hydrophilicity of nanofibers produced by measuring water absorption and contact angle as well as mechanical properties of nanofibers were considered. The results obtained from scanning electron microscopy analyses of the structure of these fibers showed that PVA had the highest viscosity of 5.64 Pa.s and the highest diameter of 260 nm, which decreased the thickness of the nanofibers with increasing PLA. And pure PLA had the lowest mean diameter of 76 nm. In the consideration of the mechanical properties of the prepared nanofibers, it was found that the combination of PLA and PVA nanofibers will lead to overlap the properties of each other and the creation of desirable mechanical properties. Moreover, in the investigation of water absorption and contact angle, it was concluded that the PVA/PLA was fully absorbed in less than 200 seconds and the samples have a contact angle of less than 52°. Finally, it was found that the average diameter of the produced nanofibers was decreased by increasing the voltage and the needle tip to collector distance by considering the PVA/PLA samples with a ratio of 50:50.


2015 ◽  
Vol 55 (4) ◽  
pp. 282 ◽  
Author(s):  
Oleksandr Trudonoshyn ◽  
Maxim Puchnin ◽  
Kostiantyn Mykhalenkov

<p>The as-cast and heat-treated structure of permanent mould castings of AlMg<sub>5</sub>Si<sub>2</sub>Mn alloys with different contents of Ti has been investigated by differential scanning calorimetry, hardness and microhardness measurements, tensile tests and fractography analyses, scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray analysis. We have established that α-Al dendrites can be nucleated on an Al-Ti substrate, and also that primary Mg<sub>2</sub>Si crystals can be nucleated on oxides, including oxides of Al and Ti compounds. The dependence of the change in mechanical properties on ageing time, and on the amount of Ti in the alloys, is shown.</p>


1990 ◽  
Vol 5 (6) ◽  
pp. 1201-1206 ◽  
Author(s):  
M. T. Clavaguera-Mora ◽  
M. D. Baró ◽  
S. Suriñach ◽  
N. Clavaguera

The kinetics of crystallization of four amorphous (or partially amorphous) melt spun Nd–Fe–B alloys induced by thermal treatment is studied by means of differential scanning calorimetry and scanning electron microscopy, In the range of temperatures explored experimentally, the crystallization process is thermally activated and generally proceeds in various stages. The Curie temperature and the crystallization behavior have been measured. The apparent activation energy of crystallization of most of the crystallization stages has been determined for each melt spun alloy. The explicit form of the kinetic equation that best describes the first stage of crystallization has been found. It follows in general the Johnson-Mehl-Avrami-Erofe'ev model, but clear deviations to that model occur for one alloy. Scanning electron microscopy demonstrates that preferentially hetereogeneous nucleation occurs at the ribbon surface which was in contact with the wheel. From crystallization kinetics results the lower part of the experimental time-temperature-transformation curves for all studied alloys are deduced and extrapolated to the high temperature limit of their range of validity, also deduced.


2013 ◽  
Vol 748 ◽  
pp. 150-154 ◽  
Author(s):  
Nurulsaidatulsyida Sulong ◽  
Anika Zafiah M. Rus

The effect of bio-polymer as compounding material in mechanical properties of HDPE is described in this study. 10% of bio-polymer was added to the HDPE and then mixed by using Brabender Plastograph machine using mixer and roller screw and then test specimens were prepared by injection moulding. The origin bio-polymer (VOP), HDPE and the compounding bio-polymer/ HDPE (CDM) were compared by using tensile test and the microstructure was investigated through scanning electron microscopy (SEM) for the fractured surface of the samples. The tensile strength of CDM was found to increase that is 17.47 MPa compared to pure VOP that only 5.69 MPa while pure HDPE has the highest tensile strength that is 20.98 MPa. By adding 10% bio-polymer to the HDPE was increased up the strength at about 207.16% while pure HDPE produced 268.91% increment with VOP as the precursor. SEM of the VOP produced brittle fracture surface while CDM have brittle and ductile surface and HDPE has totally ductile surface with highest plastic deformation properties of all.


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