scholarly journals Influence of chain extender on mechanical, thermal and morphological properties of blown films of PLA/PBAT blends

2015 ◽  
Vol 43 ◽  
pp. 27-37 ◽  
Author(s):  
Liliane Cardoso Arruda ◽  
Marina Magaton ◽  
Rosário Elida Suman Bretas ◽  
Marcelo Massayoshi Ueki
Keyword(s):  
Chain Extender ◽  
Morphological Properties ◽  
Blown Films

Development of Water Blown Bio-Based Thermoplastic Polyurethane Foams

2012 ◽  
Vol 584 ◽  
pp. 361-365 ◽  
Author(s):  
Baralu Jagannatha Rashmi ◽  
Daniela Rusu ◽  
Kalappa Prashantha ◽  
Marie France Lacrampe ◽  
Patricia Krawczak
Keyword(s):  
Compressive Strength ◽  
Cell Size ◽  
Surfactant Concentration ◽  
Thermoplastic Polyurethane ◽  
Polyurethane Foams ◽  
Chain Extender ◽  
Morphological Properties ◽  
Foam Sample ◽  
Glass Transition Temperatures ◽  
Blowing Agent

Water blown biobased thermoplastic polyurethane (TPU) foams were prepared using synthetic and biobased chain extender. The concentration of chain extender, blowing agent (BA) and surfactant were varied and their effects on physical, mechanical and morphological properties of foams were investigated. Density, compressive strength and modulus of foams decreases with an increase in BA content and increased with chain extender concentration, but do not change significantly with change in surfactant concentration. The glass-transition temperatures of the foam samples increases with an increase in BA and chain extender concentration. The cell size of the foam sample increases slightly with an increase in BA whereas chain extender concentration has no effect on cell size.

scholarly journals Development of Eco-Sustainable PBAT-Based Blown Films and Performance Analysis for Food Packaging Applications

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5395
Author(s):  
Arianna Pietrosanto ◽  
Paola Scarfato ◽  
Luciano Di Maio ◽  
Loredana Incarnato
Keyword(s):  
Food Packaging ◽  
Mechanical Response ◽  
Chain Extender ◽  
Poly Lactic Acid ◽  
Blown Films ◽  
Beneficial Effects ◽  
Flexible Packaging ◽  
Improved Performance ◽  
And Performance ◽  
Good Transparency

In this work, eco-sustainable blown films with improved performance, suitable for flexible packaging applications requiring high ductility, were developed and characterized. Films were made by blending two bioplastics with complementary properties—the ductile and flexible poly(butylene-adipate-co-terephthalate) (PBAT) and the rigid and brittle poly(lactic acid) (PLA)—at a 60/40 mass ratio. With the aim of improving the blends’ performance, the effects of two types of PLA, differing for viscosity and stereoregularity, and the addition of a commercial polymer chain extender (Joncryl®), were analyzed. The use of the PLA with a viscosity ratio closer to PBAT and lower stereoregularity led to a finer morphology and better interfacial adhesion between the phases, and the addition of the chain extender further reduced the size of the dispersed phase domains, with beneficial effects on the mechanical response of the produced films. The best system composition, made by the blend of PBAT, amorphous PLA, and the compatibilizer, proved to have improved mechanical properties, with a good balance between stiffness and ductility and also good transparency and sealability, which are desirable features for flexible packaging applications.

Use of a chain extender as a dispersing agent of the CaCO3 into PBAT matrix

2019 ◽  
Vol 54 (10) ◽  
pp. 1373-1382 ◽  
Author(s):  
Edilene de CD Nunes ◽  
Alana G de Souza ◽  
Derval dos S Rosa
Keyword(s):  
Chain Extender ◽  
Polymer Chains ◽  
Morphological Properties ◽  
Differential Scanning Calorimetric ◽  
Calorimetric Analysis ◽  
Elongation At Break ◽  
H Nmr ◽  
Dispersing Agent ◽  
A Chain ◽  
C Nmr

This paper investigates the effect of the incorporation of chain extender on the poly(butylene adipate -co-terephthalate) (PBAT) and their mixture with calcium carbonate (CaCO3) composites. Chain extender (ADR) was used to enhance the compatibility between PBAT and CaCO3, which have poor interfacial adhesion. Mechanical, thermal, and morphological properties of PBAT, PBAT/chain extender, and their composites were studied. The incorporation of the chain extender enhanced Young’s modulus and elongation at break of the neat PBAT, which is an indicator of the interaction between both materials. These results were confirmed by 1H NMR and 13C NMR (proton – hydrogen and carbon nuclear magnetic resonance, respectively). The chain extender acted by dispersing the CaCO3 particles; however, with an increase in the filler content, there is a decrease in the mechanical properties. Thermogravimetric analysis showed that chain extender has no influence on neat PBAT thermal behavior and their composites containing CaCO3. Differential scanning calorimetric analysis showed a decrease in crystallinity values of the PBAT and its composites, which is due to the physical impediment in the organization of polymer chains. Photomicrographs, obtained by scanning electron microscopy, showed that chain extender does not influence PBAT morphology. However, in the composites, chain extender enhanced the dispersion on CaCO3 particles.

The morphological, mechanical, rheological, and thermal properties of PLA/PBAT blown films with chain extender

2018 ◽  
Vol 29 (6) ◽  
pp. 1706-1717 ◽  
Author(s):  
Xin Li ◽  
Xue Ai ◽  
Hongwei Pan ◽  
Jia Yang ◽  
Guanghui Gao ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Chain Extender ◽  
Blown Films

Processing and characterization of poly(lactic acid) blended with polycarbonate and chain extender

2014 ◽  
Vol 34 (7) ◽  
pp. 665-672 ◽  
Author(s):  
Yottha Srithep ◽  
Wuttipong Rungseesantivanon ◽  
Bongkot Hararak ◽  
Krisda Suchiva
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Gel Permeation Chromatography ◽  
Chain Extender ◽  
Chain Extension ◽  
Morphological Properties ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Commercial Applications ◽  
A Chain

Abstract Currently, use of poly(lactic acid) (PLA) is limited for commercial applications because it has a low heat resistance. In this research, an increase of over 40°C heat distortion temperature (HDT) of PLA alloy was obtained by blending PLA with polycarbonate (PC) and a chain extender (CE). Molecular weight, thermal, mechanical and morphological properties of PLA and PC blend with different CE contents were investigated. Gel permeation chromatography (GPC) results showed that some PLA-PC copolymers were produced and the compatibility of the PLA phase and in the PC phase was improved via the chain extension reaction. In addition, the reaction induced by CE also affected the crystallization behaviors of PLA, as observed from differential scanning calorimetry (DSC) results and the enthalpy of melting of PLA decreased with increasing CE content. The combined effects of the CE increasing molecular weight, improving compatibility and limiting the crystallization behavior of PLA/PC alloy greatly improved the HDT.

Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ultra Violet ◽  
Active Regions ◽  
Morphological Properties ◽  
Energy Storage And Conversion ◽  
The Sun ◽  
X Rays ◽  
The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

Characterization of Tamm-Horsfall Urinary Glycoprotein

1973 ◽  
Vol 31 ◽  
pp. 420-421
Author(s):  
John P. Robinson ◽  
J. David Puett
Keyword(s):  
Electron Microscopy ◽  
Circular Dichroism ◽  
Secondary Structure ◽  
Quaternary Structure ◽  
Normal Adult ◽  
Morphological Properties ◽  
Adult Males ◽  
Circular Dichroïsm ◽  
Urinary Glycoprotein

Much work has been reported on the chemical, physical and morphological properties of urinary Tamm-Horsfall glycoprotein (THG). Although it was once reported that cystic fibrotic (CF) individuals had a defective THG, more recent data indicate that THG and CF-THG are similar if not identical.No studies on the conformational aspects have been reported on this glycoprotein using circular dichroism (CD). We examined the secondary structure of THG and derivatives under various conditions and have correlated these results with quaternary structure using electron microscopy.THG was prepared from normal adult males and CF-THG from a 16-year old CF female by the method of Tamm and Horsfall. CF female by the method of Tamm and Horsfall.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

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