Renewable Biobased Polymeric Materials: Facile Synthesis of Itaconic Anhydride-Based Copolymers with Poly(l-lactic acid) Grafts

2012 ◽  
Vol 45 (10) ◽  
pp. 4166-4174 ◽  
Author(s):  
Tomoya Okuda ◽  
Kiyoaki Ishimoto ◽  
Hitomi Ohara ◽  
Shiro Kobayashi
Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 29
Author(s):  
Seung Kyun Yoon ◽  
Jin Ho Yang ◽  
Hyun Tae Lim ◽  
Young-Wook Chang ◽  
Muhammad Ayyoob ◽  
...  

Herein, spinal fixation implants were constructed using degradable polymeric materials such as PGA–PLA block copolymers (poly(glycolic acid-b-lactic acid)). These materials were reinforced by blending with HA-g-PLA (hydroxyapatite-graft-poly lactic acid) and PGA fiber before being tested to confirm its biocompatibility via in vitro (MTT assay) and in vivo animal experiments (i.e., skin sensitization, intradermal intracutaneous reaction, and in vivo degradation tests). Every specimen exhibited suitable biocompatibility and biodegradability for use as resorbable spinal fixation materials.


2021 ◽  
pp. 40-43
Author(s):  
Дмитрий Михайлович Мяленко

Вопросы защиты окружающей среды и улучшения экологической обстановки приобретают глобальный характер. Количество производимых в России и зарубежных странах синтетических полимерных материалов постоянно увеличивается, что заставляет задуматься о подходах к разработке современных биоразлагаемых полимерных материалов из полностью возобновляемого растительного сырья. Один из таких материалов - это линейный алифатический биополимер, полученный путем гидролиза молочной кислоты: полилактид (PLA). В данной статье представлены результаты исследований способности к биоразложению полимерных материалов на основе PLA при их компостировании в течение 3 мес. The issues of environmental protection and improvement of the ecological situation are becoming global in nature. The number of synthetic polymeric materials produced from Russia and foreign countries is constantly increasing, which makes us think about approaches to the development of modern biodegradable polymeric materials from completely renewable plant materials. One such material is a linear aliphatic biopolymer made by hydrolysis of lactic acid: polylactide (PLA). This article presents the results of studies on the biodegradability of PLA-based polymeric materials when composted for 3 months.


2016 ◽  
Vol 77 ◽  
pp. 16-30 ◽  
Author(s):  
Josef Petruš ◽  
František Kučera ◽  
Jaroslav Petrůj

2010 ◽  
Vol 160 ◽  
pp. 281-286 ◽  
Author(s):  
Lars Raue ◽  
Helmut Klein

Dental enamel is the most highly mineralised and hardest biological tissue in human body [1]. Dental enamel is made of hydroxylapatite (HAP) - Ca5(PO4)3(OH), which is hexagonal (6/m). The lattice parameters are a = b = 0.9418 nm und c = 0.6875 nm [1]. Although HAP is a very hard mineral, it can be dissolved easily in a process which is known as enamel demineralization by lactic acid produced by bacteria. Also the direct consumption of acid (e.g. citric, lactic or phosphoric acid in soft drinks) can harm the dental enamel in a similar way. These processes can damage the dental enamel. It will be dissolved completely and a cavity occurs. The cavity must then be cleaned and filled. It exists a lot of dental fillings, like gold, amalgam, ceramics or polymeric materials. After filling other dangers can occur: The mechanical properties of the materials used to fill cavities can differ strongly from the ones of the dental enamel itself. In the worst case, the filling of a tooth can damage the enamel of the opposite tooth by chewing if the interaction of enamel and filling is not equivalent, so that the harder fillings can abrade the softer enamel of the healthy tooth at the opposite side. This could be avoided if the anisotropic mechanical properties of dental enamel would be known in detail, hence then another filling could be searched or fabricated as an equivalent opponent for the dental enamel with equal properties. To find such a material, one has to characterise the properties of dental enamel first in detail for the different types of teeth (incisor, canine, premolar and molar). This is here exemplary done for a human incisor tooth by texture analysis with the program MAUD from 2D synchrotron transmission images [2,3,4].


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Prisca Aude Eutionnat-Diffo ◽  
Yan Chen ◽  
Jinping Guan ◽  
Aurelie Cayla ◽  
Christine Campagne ◽  
...  

Abstract Although direct deposition of polymeric materials onto textiles through 3D printing is a great technique used more and more to develop smart textiles, one of the main challenges is to demonstrate equal or better mechanical resistance, durability and comfort than those of the textile substrates before deposition process. This article focuses on studying the impact of the textile properties and printing platform temperature on the tensile and deformations of non-conductive and conductive poly lactic acid (PLA) filaments deposited onto polyethylene terephthalate (PET) textiles through 3D printing process and optimizing them using theoretical and statistical models. The results demonstrate that the deposition process affects the tensile properties of the printed textile in comparison with the ones of the textiles. The stress and strain at rupture of the first 3D printed PLA layer deposited onto PET textile material reveal to be a combination of those of the printed layer and the PET fabric due to the lower flexibility and diffusion of the polymeric printed track through the textile fabric leading to a weak adhesion at the polymer/textile interface. Besides, printing platform temperature and textile properties influence the tensile and deformation properties of the 3D printed PLA on PET textile significantly. Both, the washing process and the incorporation of conductive fillers into the PLA do not affect the tensile properties of the extruded polymeric materials. The elastic, total and permanent deformations of the 3D-printed PLA on PET fabrics are lower than the ones of the fabric before polymer deposition which demonstrates a better dimensional stability, higher stiffness and lower flexibility of these materials.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hyun Ju Oh ◽  
Do-Kun Kim ◽  
Young Chan Choi ◽  
Seung-Ju Lim ◽  
Jae Bum Jeong ◽  
...  

Abstract Poly(l-lactic acid) (PLLA) based piezoelectric polymers are gradually becoming the substitute for the conventional piezoelectric ceramic and polymeric materials due to their low cost and biodegradable, non-toxic, piezoelectric and non-pyroelectric nature. To improve the piezoelectric properties of melt-spun poly(l-lactic acid) (PLLA)/BaTiO3, we optimized the post-processing conditions to increase the proportion of the β crystalline phase. The α → β phase transition behaviour was determined by two-dimensional wide-angle x-ray diffraction and differential scanning calorimetry. The piezoelectric properties of PLLA/BaTiO3 fibres were characterised in their yarn and textile form through a tapping method. From these results, we confirmed that the crystalline phase transition of PLLA/BaTiO3 fibres was significantly enhanced under the optimised post-processing conditions at a draw ratio of 3 and temperature of 120 °C during the melt-spinning process. The results indicated that PLLA/BaTiO3 fibres could be a one of the material for organic-based piezoelectric sensors for application in textile-based wearable piezoelectric devices.


2015 ◽  
Vol 6 (26) ◽  
pp. 4784-4793 ◽  
Author(s):  
Jia-Li Chen ◽  
Ming Su ◽  
Zhi-Qiang Jiang ◽  
Na Liu ◽  
Jun Yin ◽  
...  

Alkylethynylpalladium(ii) complexes were found to initiate the living polymerization of phenyl isocyanide leading to the formation of well-defined poly(phenyl isocyanide) with high stereoregularity and controlled helicity.


2017 ◽  
Vol 65 (7) ◽  
pp. 407-420 ◽  
Author(s):  
Phillip McClellan ◽  
Robin Jacquet ◽  
Qing Yu ◽  
William J. Landis

A novel immunohistochemistry (IHC) approach has been developed to label and localize osterix, a bone-specific transcription factor, within formalin-fixed, paraffin-embedded, tissue-engineered constructs uniquely containing synthetic polymers and human periosteal tissue. Generally, such specimens consisting in part of polymeric materials and mineral are particularly difficult for IHC identification of proteins. Samples here were fabricated from human periosteum, electrospun poly-l-lactic acid (PLLA) nanofibers, and polycaprolactone/poly-l-lactic acid (PCL/PLLA, 75/25) scaffolds and harvested following 10 weeks of implantation in athymic mice. Heat-induced and protease-induced epitope retrieval methods from selected existing protocols were examined to identify osterix. All such protease-induced techniques were unsuccessful. Heat-induced retrieval gave positive results for osterix immunohistochemical staining in sodium citrate/EDTA/Tween 20 with high heat (120C) and pressure (~30 psi) for 10 min, but the heat and pressure levels resulted in tissue damage and section delamination from slides that limited protocol effectiveness. Heat-induced epitope retrieval led to other osterix-positive staining results achieved with minimal impact on structural integrity of the tissue and polymers in sodium citrate/EDTA/Tween 20 buffer at 60C and normal pressure (14.5 psi) for 72 hr. The latter approach identified osterix-positive cells by IHC within periosteal tissue, layers of electrospun PLLA nanofibers, and underlying PCL/PLLA scaffolds of the tissue-engineered constructs.


2013 ◽  
Vol 468 ◽  
pp. 260-268 ◽  
Author(s):  
Pandian Lakshmanan ◽  
Pravin P. Upare ◽  
Ngoc-Thuc Le ◽  
Young Kyu Hwang ◽  
Dong Won Hwang ◽  
...  

2018 ◽  
Vol 103 ◽  
pp. 378-389 ◽  
Author(s):  
Josef Petruš ◽  
František Kučera ◽  
Ivana Chamradová ◽  
Josef Jančář

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