scholarly journals Environmentally Friendly Melt-Processed Chitosan/Starch Composites Modified with PVA and Lignin

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2685
Author(s):  
Weronika Janik ◽  
Anna Wojtala ◽  
Anna Pietruszka ◽  
Gabriela Dudek ◽  
Ewa Sabura

Chitosan/starch-based composites were prepared by thermomechanical processing as an alternative to the traditional solution method, with the aim of fabricating environmentally friendly materials on a larger scale. Different contents and types of lignin and poly(vinyl alcohol), PVA were incorporated into chitosan/starch compositions to improve their mechanical properties. It was demonstrated that the presence of both lignin and PVA increases the values of tensile strength and elongation at break of the composites. Moreover, it was observed that by the selection of a type of lignin and PVA, it was possible to tailor the internal microstructure of the samples. As observed in scanning electron microscope (SEM) micrographs, the introduction of lignin and PVA resulted in the formation of a smooth surface and homogeneous samples.

2011 ◽  
Vol 287-290 ◽  
pp. 302-305
Author(s):  
Xi Ping Gao ◽  
Ke Yong Tang ◽  
Yu Qing Zhang

The mechanical properties, swelling, solubility, and optical properties of composite films with poly(vinyl alcohol) (PVA) and gelatin were studied. With increasing the PVA content in the composite films, the tensile strength (TS) and elongation at break (EB) of the films increase. The swelling and solubility are different with different gelatin/PVA ratios, with the lowest at 1:5.


2021 ◽  
Vol 2120 (1) ◽  
pp. 012004
Author(s):  
May Teng Hooi ◽  
Siew Wei Phang ◽  
Hui Ying Yow ◽  
Edmund David ◽  
Ning Xin Kim ◽  
...  

Abstract This paper presents the interaction comparison of poly(vinyl) alcohol (PVA) with hydroxyapatite derived from Spanish Mackerel (SM) and Whitefin Wolf Herring (WWH) bones, in different processing method. PVA filament and solution casting method illustrated higher crystallinity in the FTIR graph as compared to the PVA pellet and filament extrusion method. Besides, minimal interactions between PVA with glycerol and HAp was observed as well. PVA pellet and solution casting method portrait higher interaction as compared to the PVA filament and extrusion method. As for the HAp of SM and WWH, WWH had higher crystallinity and better cell adhesion with a higher Ca/P ratio while SM had relatively better mechanical strength with Ca/P ratio near to stoichiometric value. The loading of HAp (0, 2.5, 5, 10, 20, 30%) does not affect interactions of PVA/HAp composite in FTIR, and thermal properties in TGA. However, it caused an increase in crystallinity at low HAp loading and decreased at higher loading of HAp above 10%. Upon addition of HAp, tensile strength increased and elongation at break decreased. As the loading of HAp increased, both mechanical properties decreased. Scaffold with WWH composite possessed lower tensile strength and higher elongation at break than SM composite. The result of mechanical properties corresponded to the SEM result. ANOVA analysis justified the effect of HAp variations and loading on the mechanical properties of the composite was prominent.


2021 ◽  
Vol 11 (19) ◽  
pp. 9168
Author(s):  
Akihiro Hiroki ◽  
Mitsumasa Taguchi

Although they have potential environmental pollution issues, soft contact lenses are value-added biodevices for medical use. Thus, it is important to reconsider starting materials and production methods to achieve sustainable development. In this study, hydrogels composed of hydroxypropyl cellulose (HPC) as an environmentally friendly material were produced by radiation and investigated for use in disposable soft contact lenses. HPC-based hydrogels with good mechanical properties and transparency were prepared by irradiation of electron beams on highly concentrated aqueous solutions containing HPC, polyethylene glycol #1000 dimethacrylate (23G), and 2-hydroxyethyl methacrylate (HEMA). The addition of 23G to HPC aqueous solutions resulted in an increase in the gel fraction as well as improved mechanical properties, such as tensile strength and elongation at break. The tensile strength and the elongation at break of HPC/HEMA/23G hydrogel obtained by the further addition of HEMA with HPC/23G aqueous solutions exhibited 0.2 MPa and 124%, which were approximately 2.0 and 1.8 times larger than these of the pure HPC hydrogel, respectively. The evaluation of the properties of the HPC/HEMA/23G hydrogel demonstrated its potential as a soft contact material with improved mechanical properties.


2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Li Juan

The nanocomposites of polypropylene (PP)/graphene were prepared by melt blending. The effects of the dosage of graphene on the flow and mechanical properties of the nanocomposites were investigated. The morphologies of fracture surfaces were characterized through scanning electron microscopy (SEM). The graphene simultaneous enhanced tensile and impact properties of nanocomposites. A 3.22% increase in tensile strength, 39.8% increase in elongation at break, and 26.7% increase in impact strength are achieved by addition of only 1 wt.% of graphene loading. The morphological behavior indicates the fracture surface of PP/graphene is more rough than that of pure PP.


2011 ◽  
Vol 284-286 ◽  
pp. 459-463 ◽  
Author(s):  
Yuan Yuan Qi ◽  
Bin Liu ◽  
Xing Bin Yan

Nanofibrous scaffolds of PVA and HA were prepared by electrospinning. SEM showed the scaffolds had porous nanofibrous morphology, and the diameter of the fibers was in the range of 200-1000 nm. FTIR and XRD showed the presence of HA in the scaffolds. The mechanical properties of the scaffolds changed by the adding content of HA. For the nanoscaffolds with 2wt % HA, the ultimate tensile strength and the elongation at break was 7.5 MPa and 17%. The PVA/HA nanoscaffolds prepared by electrospinning indicated good properties, and had a potential applications in bone tissue engineering and drug delivery systems.


2011 ◽  
Vol 332-334 ◽  
pp. 1739-1742 ◽  
Author(s):  
Ling Li ◽  
Zheng Wei Jin ◽  
Jian Qing Wang

A novel chitosan/poly(vinyl alcohol) composite packaging films were prepared by the casting method, and the effects of chitosan concentration on the structures, mechanical properties, permeability for oxygen and water vapor were discussed in this study. Mechanical properties of these films, which were evaluated by the tensile test and the barrier properties showed that the elongation at break (E) of the composite films decreased rapidly with the addition of chitosan, whereas, the tensile strength (TS) presented an almost opposite trend. Both the water vapour and oxygen transmission rate values were increased with the increasing amount of the chitosan in the composite films. Based on the obtained results, the better property of the composites films would be prepared chitosan/poly(vinyl alcohol) blends at a weight ratio of 3/5, and the tensile strength and elongation at break of the packaging films were 34.12 MPa, 40.24 % respectively. It was also observed that the water vapor permeability coefficient (Pv) and the oxygen permeability coefficient (P) of chitosan/poly(vinyl alcohol) composite packaging films prepared with weight ratio of 3/5 were 1.99×10-15 g•cm/cm2•s•Pa and 7.98×10-16 cm3•cm/cm2•s•Pa respectively. The composite films in this paper can be used in fresh-keeping or other fields as a kind of green packaging material.


2015 ◽  
Vol 4 (3) ◽  
pp. 23-28
Author(s):  
Fadhilla Asyri ◽  
Kartini Noor Hafni ◽  
A. Haris Simamora

This study aims was to determine the effect of palm oil fuel ash (POFA) composite as filler on the physical and mechanical properties of high impact polystyrene (HIPS) composites. The research methodology included preparation of raw materials, treatment POFA (hydration process of POFA), mixing using tumbler and then extruder, molding composite specimens, and testing. The variables used were weight ratio of HIPS with 140 mesh POFA at 95/5; 92.5/7.5; 90/10. The composites were tested by Fourier Transform Infrared (FTIR), ash content, specific gravity, tensile strength, elongation at break, impact strength, hardness test, and Scanning Electron Microscopy (SEM). The results of FTIR characterization shows the formation of –OH bonding that was suspected as Si-OH or Si-hydrat. Results of physical and mechanical properties of the composites shows that increase of the filler composition in HIPS-POFA composites until the ratio of 90/10, increase the specific gravity to 7.2% of the original, tensile strength did not change significantly to 28.4 MPa, elongation at break decreased to 2.7%, impact strength decreased to 3.183 KJ/m2, and the hardness increased to 110.5, and Scanning Electron Microscopy (SEM) test show the transformation of POFA structure on treated POFA and intercalation between the matrix and POFA.


2013 ◽  
Vol 834-836 ◽  
pp. 237-240 ◽  
Author(s):  
Kanyakorn Pawarangkool ◽  
Wirunya Keawwattana

In this work, hydroxyapatite (HAp) was produced from crocodile bones by thermal process at 900°C. X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR) and Scanning electron microscope (SEM) were used to characterize the obtained HAp. Polylactic acid (PLA)/HAp composites were prepared by melt blending as follows: 95/5, 90/10 and 85/15 (weight ratio). The effect of the amount of HAp on the mechanical properties including tensile strength, modulus, elongation at break and impact strength of PLA/HAp composites was undertaken. It was found that tensile strength and elongation at break of the composites decreased with an increase of HAp content, while modulus and impact strength showed no significant effect.


2012 ◽  
Vol 488-489 ◽  
pp. 62-66
Author(s):  
Jareenuch Rojsatean ◽  
Supakij Suttireungwong ◽  
Manus Seadan

The blend of poly(styrene-co-acrylonitrile) (SAN) and natural rubber (NR) is immiscible and incompatible which lead to poor mechanical properties. Many methods can be carried out to improve the compatibility. In this work, the potential of various reactive compatibilizers in SAN and NR blend was explored. The morphological and mechanical properties were compared. The melt blending of SAN and NR were prepared in an internal mixer with various types of reactive agent such as styrene-co-maleic anhydride (SMA), maleic anhydride (MA), peroxide and mixed reactive agents. The morphological textures of the blends were investigated by scanning electron microscope. Mechanical properties including tensile strength, impact strength and elongation at break were measured. The results of morphological observations revealed that SAN/NR blend with reactive agent, the mixture of SMA and MA show the smallest and the most uniform dispersed NR particles, where the size of NR particle is about 1 µm. The mechanical properties of the blends revealed impact strength and elongation at break were increased with addition of reactive agents. SAN/NR blend with the mixture of SMA and MA showed the highest elongation at break but it had lower impact strength than the blend with SMA.


2021 ◽  
Vol 56 (3) ◽  
pp. 215-222
Author(s):  
MA Hashem ◽  
MHR Sheikh ◽  
Rahamatullah ◽  
M Biswas ◽  
MA Hasan ◽  
...  

In tannery, fleshing is the unavoidable solid waste which has negative effect on the environment. Fleshing contains fat, and protein.In this work, fat extracted fleshing was used for composite fabrication. After collecting limed fleshing, fat was extracted in water bath.The fat extracted fleshing was dried, ground,passes through 80-mesh and homogenized.For proper adhesion and bonding with fleshing powder, epoxy resin and hardener were mixed at various ratios and poured onto an aluminum sheetfor 24 h curing. The mechanical properties of the composite were investigated by tensile strength, elongation at break, and Young’s modulus. The composite was characterized by Fourier Transform Infrared (FTIR) Spectroscopy and Scanning Electron Microscope (SEM) for related functional groups and surface analysis. The investigation provided satisfactory information on the proper bonding of the fleshing powder and resin/hardener. The approach explores the valorization of he waste for managing solid waste in the tannery. Bangladesh J. Sci. Ind. Res.56(3), 215-222, 2021


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