scholarly journals Characterization of PLA/PBSeT Blends Prepared with Various Hexamethylene Diisocyanate Contents

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 197
Author(s):  
Sun Jong Kim ◽  
Hyo Won Kwak ◽  
Sangwoo Kwon ◽  
Hyunho Jang ◽  
Su-il Park

Poly (lactic acid) (PLA) is the most widely available commercial bioplastic that is used in various medical and packaging applications and three-dimensional filaments. However, because neat PLA is brittle, it conventionally has been blended with ductile polymers and plasticizers. In this study, PLA was blended with the high-ductility biopolymer poly (butylene-sebacate–co–terephthalate) (PBSeT), and hexamethylene diisocyanate (HDI) was applied as a crosslinking compatibilizer to increase the miscibility between the two polymers. PLA (80%) and PBSeT (20%) were combined with various HDI contents in the range 0.1–1.0 parts-per-hundred rubber (phr) to prepare blends, and the resulting physical, thermal, and hydrolysis properties were analyzed. Fourier-transform infrared analysis confirmed that –NH–C=OO− bonds had formed between the HDI and the other polymers and that the chemical bonding had influenced the thermal behavior. All the HDI-treated specimens showed tensile strengths and elongations higher than those of the control. In particular, the 0.3-phr-HDI specimen showed the highest elongation (exceeding 150%) and tensile strength. In addition, all the specimens were hydrolyzed under alkaline conditions, and all the HDI-treated specimens degraded faster than the neat PLA one.

2018 ◽  
Vol 33 (3) ◽  
pp. 289-304 ◽  
Author(s):  
Kuhananthan Nanthakumar ◽  
Chan Ming Yeng ◽  
Koay Seong Chun

This research covers the preparation of poly(lactic acid) (PLA)/sugarcane leaves fibre (SLF) biofilms via a solvent-casting method. The results showed that the tensile strength and Young’s modulus of PLA/SLF biofilms increased with the increasing of SLF content. Nevertheless, the elongation at break showed an opposite trend as compared to tensile strength and Young’s modulus of biofilms. Moreover, water absorption properties of PLA/SLF biofilms increased with the increasing of SLF content. In contrast, the tensile strength and Young’s modulus of biofilms were enhanced after bleaching treatment with hydrogen peroxide on SLF, but the elongation at break and water absorption properties of bleached biofilms were reduced due to the improvement of filler–matrix adhesion in biofilms. The tensile and water properties were further discussed using B-factor and Fick’s law, respectively. Furthermore, the functional groups of unbleached and bleached SLF were characterized by Fourier transform infrared analysis.


2012 ◽  
Vol 32 (6-7) ◽  
pp. 435-444 ◽  
Author(s):  
Hsin-Tzu Liao ◽  
Chin-San Wu

Abstract Melt blending of polylactide (PLA), poly(ε-caprolactone) (PCL), and wood flour (WF) was performed in an effort to overcome the major drawbacks (brittleness and high price) of PLA. In addition, the acrylic acid (AA)-grafted PLA70PCL30 (PLA70PCL30-g-AA) was used as the alternative for the preparation of ternary blends to improve the compatibility and the dispersability of WF within the PLA70PCL30 matrix. As expected, PCL improved the elongation at break and the toughness of PLA but decreased the tensile strength and modulus. Because the hydrophilic WF is dispersed physically in the hydrophobic PLA70PCL30 matrix, as the result of Fourier transform infrared analysis, the mechanical properties of PLA70PCL30 became noticeably worse when it was blended with WF. This problem was successfully conquered by using PLA70PCL30-g-AA to replace PLA70PCL30 due to the formation of an ester carbonyl group between PLA70PCL30-g-AA and WF. Furthermore, the PLA70PCL30-g-AA/WF blend provided a plateau tensile strength at break when the WF content was up to 50 wt%. PLA70PCL30/WF exhibited a tensile strength at break of approximately 3–25 MPa more than PLA70PCL30-g-AA/WF. By using p-cresol and tyrosinase, the enzymatic biodegradable test showed that PLA70PCL30-g-AA is somewhat more biodegradable than PLA70PCL30 because the former has better water absorption. After 16 weeks, the weight loss of the PLA70PCL30/WF (50 wt%) composite was >80%. PLA70PCL30-g-AA/WF exhibited a weight loss of approximately 1–12 wt% more than PLA70PCL30-g-AA/WF. It was also found that the addition of WF to PLA70PCL30 or PLA70PCL30-g-AA decreased the crystallinity of PLA and PCL in PLA70PCL30 or PLA70PCL30-g-AA and then increased their biodegradable property.


2020 ◽  
Vol 7 (2) ◽  
pp. 39
Author(s):  
Sun-Young Nam ◽  
Dayoung Youn ◽  
Gyeong Hoe Kim ◽  
Ji Hwa Chai ◽  
Hyang Ran Lim ◽  
...  

In the past, acellular dermal matrices (ADMs) have been used in implant-based breast reconstruction. Various factors affect the clinical performance of ADMs since there is a lack of systematic characterization of ADM tissues. This study used BellaCell HD and compared it to two commercially available ADMs—AlloDerm Ready to Use (RTU) and DermACELL—under in vitro settings. Every ADM was characterized to examine compatibility through cell cytotoxicity, proliferation, and physical features like tensile strength, stiffness, and the suture tensile strength. The BellaCell HD displayed complete decellularization in comparison with the other two ADMs. Several fibroblasts grew in the BellaCell HD with no cytotoxicity. The proliferation level of fibroblasts in the BellaCell HD was higher, compared to the AlloDerm RTU and DermACELL, after 7 and 14 days. The BellaCell HD had a load value of 444.94 N, 22.44 tensile strength, and 118.41% elongation ratio, and they were higher than in the other two ADMs. There was no significant discrepancy in the findings of stiffness evaluation and suture retention strength test. The study had some limitations because there were many other more factors useful in ADM’s testing. In the study, BellaCell HD showed complete decellularization, high biocompatibility, low cytotoxicity, high tensile strength, high elongation, and high suture retention strengths. These characteristics make BellaCell HD a suitable tissue for adequate and safe use in implant-based breast reconstruction in humans.


Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3487
Author(s):  
Walid Abotbina ◽  
S. M. Sapuan ◽  
M. T. H. Sultan ◽  
M. F. M. Alkbir ◽  
R. A. Ilyas

This work aims to develop cornstarch (CS) based films using fructose (F), glycerol (G), and their combination (FG) as plasticizers with different ratios for food packaging applications. The findings showed that F-plasticized film had the lowest moisture content, highest crystallinity among all films, and exhibited the highest tensile strength and thermostability. In contrast, G-plasticized films showed the lowest density and water absorption with less crystallinity compared to the control and the other plasticized film. In addition, SEM results indicated that FG-plasticized films had a relatively smoother and more coherent surface among the tested films. The findings have also shown that varying the concentration of the plasticizers significantly affected the different properties of the plasticized films. Therefore, the selection of a suitable plasticizer at an appropriate concentration may significantly optimize film properties to promote the utilization of CS films for food packaging applications.


Author(s):  
Yosuke Fukuda ◽  
Nobuto Yoshinari ◽  
Takumi Konno

Treatment of an S-bridged pentanuclear AgI3CoIII2complex, [Ag3{Co(L)}2]3+[L3–= N(CH2NHCH2CH2S−)3], in which two tris(thiolate)-type mononuclear CoIIIunits ([Co(L)]) are bridged by three AgIions through S atoms, with iodomethane (CH3I) gave a new CoIIImononuclear complex, [Co(LMe2)]2+[LMe2−= N(CH2NHCH2CH2S−)(CH2NHCH2CH2SCH3)2], systematic name: {2-[(bis{[2-(methylsulfanyl)ethyl]aminomethyl}aminomethyl)amino]ethanethiolato}cobalt(III) bis(hexafluoridophosphate). This cationic complex was crystallized with PF6−anions to form the title compound, [Co(LMe2)](PF6)2. In the [Co(LMe2)]2+cation, two of three thiolate groups in [Co(L)] are methylated while one thiolate group remains unreacted. Although a total of eight stereoisomers are possible for [Co(LMe2)]2+, only a pair of enantiomers {ΛRR- and ΔSS-[Co(LMe2)]2+} are selectively formed. In the crystal, the complex cations and the PF6−anions are connected through weak N—H...F, C—H...F and C—H...S hydrogen bonds into a three-dimensional structure. Two F atoms in one PF6anion are disordered over two sets of sites with refined occupancies of 0.61 (4) and 0.39 (4) and two F atoms in the other PF6−anion are disordered over two sets of sites with occupancies of 0.5.


2014 ◽  
Vol 353 ◽  
pp. 90-95
Author(s):  
Tatiana Mayumi Moori ◽  
Mauro Cesar Terence ◽  
Nilson Casimiro Pereira ◽  
Sonia Braunstein Faldini ◽  
Leila Figueiredo de Miranda

This study analyzed nine polypropylene (PP) and low-density polyethylene (LDPE) blends where the mass concentrations of each sample were changed, proportionally. The aim was to investigate the tensile strength by means of these polymers best combination, before and after its exposal to gamma rays. The results showed that the 20/80 - PP/LDPE blend had a better performance concerning mechanical properties after irradiation, where the maximums tensile stress had an average increase of 30% in 30 and 50 kGy doses and 33% in the 200 kGy dose. On the other hand, it was verified that the higher blend's PP concentration, the higher its tensile strength will be (except for 100 kGy and 200 kGy doses which PP concentration over 70% can cause eventual degradation in the polymeric chains of the blend).


2009 ◽  
Vol 71-73 ◽  
pp. 589-592
Author(s):  
S.J. Kleinübing ◽  
Eric Guibal ◽  
Meuris Gurgel Carlos da Silva

Fundamental investigation on adsorption of Cu2+ and Ni2+ ions on Sargassum sp. was performed in fixed-bed column. The Langmuir isotherm fitted well the biosorption equilibrium and the maximum Cu2+ and Ni2+ uptake capacities were 1.35 and 1.06 mmolg- 1, respectively. Mappings of copper and nickel in the algae surface using energy dispersive X-ray spectroscopy indicated a homogeneous distribution of Cu- and Niadsorbent sites. Fourier-transform infrared analysis revealed that the main chemical groups involved in the copper and nickel biosorption were carboxyl, ether, alcoholic, amino, and sulphonic groups.


2018 ◽  
Vol 917 ◽  
pp. 3-6 ◽  
Author(s):  
Muhammad Haniff ◽  
Mohd Bijarimi ◽  
M.S. Zaidi ◽  
Ahmad Sahrim

PLA has limited applications due to its inherent brittleness, toughness and low elongation at break. One of the options for improvement is through blending with polyoxymethylene (POM). Melt blending of polylactic acid (PLA) and polyoxymethylene (POM) at 90/10 PLA/POM composition was carried out in a twin-screw extruder. The PLA/POM was loaded with 1 – 5 wt.% of nanoclay (Cloisite C20). The blends were then characterized for mechanical, morphological, chemical and thermal properties. It was found that tensile strength, Young's modulus, and elongation at break improved when the loadings of nanoclay were increased. Chemical analysis by FTIR revealed that PLA/POM blend is immiscible.


2018 ◽  
Vol 26 (8-9) ◽  
pp. 446-453 ◽  
Author(s):  
Chi-Hui Tsou ◽  
Chen Gao ◽  
Manuel De Guzman ◽  
Dung-Yi Wu ◽  
Wei-Song Hung ◽  
...  

Poly(lactic acid) (PLA) was thermally blended with adipate ester (AE) to enhance the toughness of PLA. All specimens which were biodegradable materials were prepared using a plasticorder. Differential scanning calorimetry and Fourier-transform infrared spectroscopy indicated that the PLA structure was looser because of the presence of the AE additive. The elongation at break and biodegradable property increased substantially with increasing amounts of AE. The results reveal that excessive amounts of plasticizer would cause the exudation of AE from the PLA/AE composites, which was ascribed to the plasticizer migration phenomenon.


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