scholarly journals Influence of Chain-Extension Reaction on Stereocomplexation, Mechanical Properties and Heat Resistance of Compressed Stereocomplex-Polylactide Bioplastic Films

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1218 ◽  
Author(s):  
Yodthong Baimark ◽  
Sumet Kittipoom
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Heat Resistance ◽  
Tensile Testing ◽  
Chain Extender ◽  
Chain Extension ◽  
Melt Blending ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Xrd Patterns

Stereocomplex polylactide (scPLA) films were prepared by melt blending of poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) with and without an epoxy-based chain extender before compression molding. The obtained scPLA films were characterized through differential scanning calorimetry, X-ray diffractometry (XRD), tensile testing and dimensional stability to heat. XRD patterns revealed that all the scPLA films had only stereocomplex crystallites. The obtained results showed that the chain-extension reaction improved mechanical properties of the scPLA films, however, it suppressed stereocomplexation and heat resistance.

Research on compatibility and surface of high impact bio-based polyamide

2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Crystallization Behavior ◽  
High Impact ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

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.

Plasticizer effect on melt blending of polylactide stereocomplex

e-Polymers ◽  
2017 ◽  
Vol 17 (5) ◽  
pp. 409-416 ◽  
Author(s):  
Yottha Srithep ◽  
Dutchanee Pholharn
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Crystallization Rate ◽  
Wide Angle ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Neat Plla ◽  
Internal Mixer

AbstractPoly(l-lactide) (PLLA)/poly(d-lactide) (50/50) with plasticizer contents ranging from 2% to 16% w/w were prepared by melt blending using an internal mixer. Wide-angle X-ray diffraction, Fourier transform infrared spectroscopy and differential scanning calorimetry results confirmed that complete stereocomplex polylactide crystallites without any homocrystallites were produced. Compared to neat PLLA, the melting temperature of the stereocomplex polylactide and its plasticized samples was approximately 55°C higher. Higher plasticizer contents decreased glass transition temperature of the stereocomplex, which implied higher flexibility and enhanced the crystallization rate. However, the plasticizer in the stereocomplex reduced the thermal stability.

Crystallization Behavior and Mechanical Properties of PP/EVA Blends

2014 ◽  
Vol 1033-1034 ◽  
pp. 869-872
Author(s):  
Kun Yan Wang
Keyword(s):  
Mechanical Properties ◽  
Crystallization Behavior ◽  
Ethylene Vinyl Acetate ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Blending Method ◽  
Twin Screw

Polypropylene (PP)/ethylene-vinyl acetate (EVA) blends were prepared using a twin-screw extruder by melt blending method. The influences of the EVA contents in PP/EVA blends on crystallization behavior and mechanical properties were investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). XRD results show that the EVA not change the crystal structure in the blends but only decrease the intensity of the diffraction peak. DSC results showed that the melting point and crystallization point decreased when EVA added to the blend. The tensile properties of PP/EVA blend become much better.

scholarly journals DMSO Deintercalation in Kaolinite–DMSO Intercalate: Influence of Solution Polarity on Removal

2021 ◽  
Vol 5 (4) ◽  
pp. 97
Author(s):  
Berenger ZOGO MFEGUE ◽  
Jean Aimé MBEY ◽  
Sandotin Lassina COULIBALY ◽  
Vincent Laurent ONANA ◽  
Paul-Désiré NDJIGUI
Keyword(s):  
Differential Scanning Calorimetry ◽  
Removal Rate ◽  
Solvent Polarity ◽  
Diffraction Peak ◽  
Distilled Water ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Infra Red ◽  
Xrd Patterns

This study focused on the deintercalation of dimethyl sulfoxide (DMSO) from a kaolinite–DMSO complex in various solvents. The use of kaolinite as filler in polymer–clay composite generally faced the difficulty of kaolinite dispersion due to its high cohesion. For improved dispersion of kaolinite within a given matrix, previous intercalation of small polar molecules is usually done prior to its displacement during composite-making. The influence of the solvent polarity on the deintercalation in analyzed here to understand its role during the deintercalation process. The intercalation of the DMSO was done by solution-mixing and its displacement was done in distilled water, ethyl acetate, and acetone. The products of deintercalation were analyzed using Fourier transform infra-red (FTIR), powder X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The weakening of the kaolinite cohesion after DMSO intercalation is demonstrated through the broadening of the diffraction peak associated with the kaolinite on XRD patterns. From FTIR spectra, the weakening is associated with the displacement to low wavenumbers of the Si–O or Al–O vibration bands within the kaolinite–DMSO complex. The kaolinite dehydroxylation temperatures from DSC show that the rate of DMSO displacement affects the ordering of the recovered kaolinite. The crystallite size of the kaolinite is reduced from the raw to the recovered kaolinite after DMSO displacement, indicating an exfoliation of the kaolinite. From these results, it is found that the removal of the DMSO from the kaolinite–DMSO complex is influenced by solvent polarity. The higher the polarity, the greater the removal of the DMSO from the complex. Solvent polarity affects the rate of DMSO displacement, which influences the ordering of the recovered kaolinite. It is suggested that solvent polarity can be used to control the removal rate of DMSO, which may be key to the dispersion of the kaolinite platelets.

scholarly journals Polyurethane/Nanosilver-Doped Halloysite Nanocomposites: Thermal, Mechanical Properties, and Antibacterial Properties

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2729 ◽  
Author(s):  
Jui-Ting Sun ◽  
Jia-Wun Li ◽  
Chi-Hui Tsou ◽  
Jen-Chieh Pang ◽  
Ren-Jei Chung ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Thermal Stability ◽  
Pyridine Ring ◽  
Antibacterial Properties ◽  
Chain Extension ◽  
Gravimetric Analysis ◽  
Chain Segment ◽  
Scanning Calorimetry ◽  
X Ray

In this study, the researchers successfully embellished the surface of halloysite (Ag/HNTs) with silver using halloysite, silver nitrate (AgNO3), and polyvinylpyrrolidone (PVP). The researchers then prepared polyurethane that contained pyridine ring by using 4,4′-diphenylmethane diisocyanate (MDI) and polytetramethylene glycol (PTMG) as the hard chain segment and the soft chain segment of polyurethane (PU), as well as 2,6-pyridinedimethanol (2,6-PDM) as the chain extension agent. This was followed by the preparation of Ag/HNTs/PUs nanocomposite thin films, achieved by mixing Ag/HNTs with different ratios into polyurethane that contains pyridine ring. First, the Ag/HNTs powders were analyzed using energy-dispersive X-ray spectroscopy, X-ray diffraction, and transmission electron microscopy. Subsequently, Fourier-transform infrared spectroscopy was used to examine the dispersibility of Ag/HNTs in PU, whereas the thermal stability and the viscoelasticity of Ag/HNTs/PU were examined using thermal gravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. When the mechanical properties of Ag/HNTs/PU were tested using a universal strength tester, the results indicated a maximum increase of 109.5% in tensile strength. The researchers then examined the surface roughness and the hydrophobic ability of the Ag/HNTs/PU thin films by using atomic force microscopy and water contact angle. Lastly, antibacterial testing on Escherichia coli revealed that when the additive of Ag/HNTs reached 2.0 wt%, 99.3% of the E. coli were eliminated. These results indicated that the addition of Ag/HNTs into PU could enhance the thermal stability, mechanical properties, and antibacterial properties of PU, implying the potential of Ag/HNTs-02 as biomedicine material.

Controlling stereocomplexation, heat resistance and mechanical properties of stereocomplex polylactide films by using mixtures of low and high molecular weight poly(D-lactide)s

e-Polymers ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 485-490 ◽  
Author(s):  
Yaowalak Srisuwan ◽  
Yodthong Baimark
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Heat Resistance ◽  
Tensile Properties ◽  
Tensile Testing ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
Film Series ◽  
High Molecular Weight Poly

AbstractStereocomplex polylactide (scPLA) films were prepared by blending poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) solutions before solvent evaporation. The PLLA/PDLA ratios were 80/20 and 60/40 (w/w). PDLAs with low and high molecular weights (M.W.) were used as PDLA mixtures. The scPLA films with different low/high M.W. PDLA ratios were investigated for both the 80/20 and 60/40 (w/w) scPLA film series. Stereocomplexation, heat resistance and the mechanical properties of the scPLA films were studied by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and tensile testing, respectively. The results indicated that low M.W. PDLA can enhance the stereocomplexation and heat resistance of scPLA films while the high M.W. PDLA can improve tensile properties of scPLA films. It was concluded that the stereocomplexation, heat resistance and tensile properties of scPLA films could be controlled by adjusting the low/high M.W. PDLA ratio in PDLA fraction.

scholarly journals Cure Kinetics and Properties of Blends of Epoxy Resins with Polyethersulfone

CONVERTER ◽  
2021 ◽  
pp. 476-481
Author(s):  
Tiantian Feng, Et al.
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Heat Resistance ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Cure Kinetics ◽  
Scanning Calorimetry

In this article,polyethersulfone and flourene-coating epoxy resin were utilized tomodify both the toughness and the mechanical properties of traditional epoxy resins. The cure kineticsand the thermal stabilityof the resultedblends were tested by differential scanning calorimetry technology and thermogravimetric analysis, respectively. Additionally, the mechanical properties of resulted thermosets were discussed after tested by Dynamic Thermomechanical Analyzer.When compared to the traditional epoxides, the obtained blends exhibit much better heat resistance, thermal stability and mechanical properties.

Preparation and Performance Research of the PBC / PLA Biodegradable Film

2013 ◽  
Vol 470 ◽  
pp. 62-65 ◽  
Author(s):  
Xiao Hua Gu ◽  
Bao Yun Xu ◽  
Peng Zeng ◽  
Xi Wei Zhang ◽  
Xi Jun Liu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Tensile Testing ◽  
Chain Extender ◽  
Elongation Rate ◽  
Biodegradable Material ◽  
Scanning Calorimetry ◽  
Biodegradable Film ◽  
And Performance ◽  
Performance Research

This paper mainly describes a novel biodegradable material poly (butylene carbonate) (PBC) to blending toughing modification for polylactic acid (PLA), and prepared the PBC/PLA biodegradable film) of improved toughness. To research the effect of thermol performance and mechanical properties (tensile strength and breaking elongation rate) through Fourier transform infrared spectroscopy (FTIR), differential thermal scanning calorimetry analysis (DSC) and tensile testing to expound different ratio of PBC and additive plasticizer, (lubricant and chain extender) .

scholarly journals Improvement in Mechanical Properties and Heat Resistance of PLLA-b-PEG-b-PLLA by Melt Blending with PDLA-b-PEG-b-PDLA for Potential Use as High-Performance Bioplastics

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Supasin Pasee ◽  
Yodthong Baimark
Keyword(s):  
Mechanical Properties ◽  
Ethylene Glycol ◽  
Heat Resistance ◽  
High Performance ◽  
Melt Processing ◽  
Melt Blending ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Blend Films ◽  
Poly Ethylene

Ecofriendly poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-b-PEG-b-PLLA) are flexible bioplastics. In this work, the blending of poly(D-lactide)-b-poly(ethylene glycol)-b-poly(D-lactide) (PDLA-b-PEG-b-PDLA) with various blend ratios for stereocomplex formation has been proved to be an effective method for improving the mechanical properties and heat resistance of PLLA-b-PEG-b-PLLA films. The PLLA-b-PEG-b-PLLA/PDLA-b-PEG-b-PLDA blend films were prepared by melt blending followed with compression molding. The stereocomplexation of PLLA and PDLA end-blocks were characterized by differential scanning calorimetry and X-ray diffraction (XRD). The content of stereocomplex crystallites of blend films increased with the PDLA-b-PEG-b-PDLA ratio. From XRD, the blend films exhibited only stereocomplex crystallites. The stress and strain at break of blend films obtained from tensile tests were enhanced by melt blending with the PDLA-b-PEG-b-PDLA. The heat resistance of blend films determined from testing of dimensional stability to heat and dynamic mechanical analysis were improved with the PDLA-b-PEG-b-PDLA ratio. The sterecomplex PLLA-b-PEG-b-PLLA/PDL-b-PEG-b-PDLA films prepared by melt processing could be used as flexible and good heat-resistance packaging bioplastics.

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