Improvement in mechanical, physical and biological properties of eucalyptus and pine woods by raw pine resin in situ polymerization

2021 ◽  
Vol 166 ◽  
pp. 113495
Author(s):  
Andrey Pereira Acosta ◽  
Kelvin Techera Barbosa ◽  
Sandro Campos Amico ◽  
André Luiz Missio ◽  
Rafael de Avila Delucis ◽  
...  
Keyword(s):  
In Situ Polymerization ◽  
Biological Properties ◽  
Pine Resin

Production of Personalized Thyroid Cartilage Scaffold and Histological Analysis

2014 ◽  
Vol 881-883 ◽  
pp. 473-478
Author(s):  
Wei Xia ◽  
Gao Xiang Cao ◽  
Long Cheng Zhang ◽  
Jie Liao ◽  
Jian Min Zeng
Keyword(s):  
Histological Analysis ◽  
In Situ Polymerization ◽  
Thyroid Cartilage ◽  
Biological Properties ◽  
Bone Morphogenetic Protein 2 ◽  
Cartilage Defects ◽  
Organic Additives ◽  
Morphogenetic Protein ◽  
Specimen Density

To meet the bone defect on the personalized needs of implantation, this study presents the manufacture of personalized thyroid cartilage hydroxyapatite (HA) scaffold by the rapid prototyping(RP) technique combined with CT image reconstruction and employs the foaming of suspensions prior to the in situ polymerization of organic monomers contained in the compositions. The organic additives are eliminated at temperatures above 300°C, and sintering is carried out for consolidation of the ceramic matrix. Spherical interconnected cells with sizes ranging from 100μm to 250μm characterize the porous structure, depending on the specimen density. The biological properties of porous personalized scaffolds loaded with bone morphogenetic protein 2 (rhBMP-2) were evaluated, by which a simulated surgical method of thyroid cartilage defects in rabbits and repairing with artificial scaffolds, and compared with rhBMP-2 loaded dense personalized or porous non-personalized scaffolds. The results of the histological analysis and the electronic laryngoscope inspection of airway indicate that rhBMP-2/HA/ porous personalized scaffolds is a promising composite having osteogenic efficient enough for repairing thyroid cartilage defects.

The effect of carbon nanoparticles on biological properties of polyester nanocomposites

2017 ◽  
Vol 31 (10) ◽  
pp. 1328-1336 ◽  
Author(s):  
Zygmunt Staniszewski ◽  
Agnieszka Piegat ◽  
Wieslawa Okroj ◽  
Magdalena Walkowiak-Przybylo ◽  
Witold Jakubowski ◽  
...  
Keyword(s):  
Bacterial Adhesion ◽  
Carbon Nanoparticles ◽  
Cellular Response ◽  
In Situ Polymerization ◽  
Bacterial Colonization ◽  
Polymer Structure ◽  
Biological Properties ◽  
Medical Applications ◽  
Carbon Nanoparticle

The aim of present study was to determine the hemocompatibility, cellular response of endothelial cells and bacterial adhesion to a new polyester nanocomposite. The carbon nanoparticle nanocomposite was prepared via in situ polymerization of monomers to obtain material of hardness 55 Sh D similar to polyurethanes used in medical applications, for example, in heart-assisting devices. The carbon nanoparticle-containing polyester exhibits markedly reduced bacterial colonization, as compared to commercially available polyurethanes. Further the nanocomposite possesses markedly improved hemocompatibility, as determined by flow cytometry, and robust endothelialization. Possible explanations for these beneficial properties include surface nanoroughness of carbon nanoparticle-containing nanocomposites and presence of fatty acid sequences within polymer structure.

Juvenile and Mature Pinewoods Treated by in situ Polymerization with Poly(vinyl acetate)

2021 ◽  
Author(s):  
Andrey Acosta ◽  
Ezequiel Gallio ◽  
Paula Zanatta ◽  
Henrique Schulz ◽  
Rafael de Avila Delucis ◽  
...  
Keyword(s):  
Vinyl Acetate ◽  
In Situ Polymerization

scholarly journals Morphology and crystallization kinetics of Rubber-modified Nylon 6 Prepared by Anionic In-situ Polymerization

2020 ◽  
Vol 27 (1) ◽  
pp. 204-215
Author(s):  
Hongkai Zhao ◽  
Dengchao Zhang ◽  
Yingshuang Li
Keyword(s):  
Crystallization Kinetics ◽  
In Situ Polymerization ◽  
Good Description ◽  
Nylon 6 ◽  
Avrami Equation ◽  
Infrared Analysis ◽  
Chain Segment ◽  
The Impact ◽  
Kinetics Of

AbstractIn this work, we modified nylon 6 with liquid rubber by in-situ polymerization. The infrared analysis suggested that HDI urea diketone is successfully blocked by caprolactam after grafting on hydroxyl of HTPB, and the rubber-modified nylon copolymer is generated by the anionic polymerization. The impact section analysis indicated the rubber-modified nylon 6 resin exhibited an alpha crystal form.With an increase in the rubber content, nylon 6 was more likely to generate stable α crystal. Avrami equation was a good description of the non-isothermal crystallization kinetics of nylon-6 and rubber-modified nylon-6 resin. Moreover, it is found that the initial crystallization temperature of nylon-6 chain segment decreased due to the flexible rubber chain segment. n value of rubber-modified nylon-6 indicated that its growth was the coexistence of two-dimensional discoid and three-dimensional spherulite growth. Finally, the addition of the rubber accelerated the crystallization rate of nylon 6.

scholarly journals Effect of Na- and Organo-Modified Montmorillonite/Essential Oil Nanohybrids on the Kinetics of the In Situ Radical Polymerization of Styrene

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 474
Author(s):  
Ioannis S. Tsagkalias ◽  
Alexandra Loukidi ◽  
Stella Chatzimichailidou ◽  
Constantinos E. Salmas ◽  
Aris E. Giannakas ◽  
...  
Keyword(s):  
Essential Oil ◽  
Radical Polymerization ◽  
Food Packaging ◽  
In Situ Polymerization ◽  
Average Molecular Weight ◽  
Monomer Conversion ◽  
Hydroxyl Groups ◽  
Modified Montmorillonite ◽  
Kinetics Of

The great concern about the use of hazardous additives in food packaging materials has shown the way to new bio-based materials, such as nanoclays incorporating bioactive essential oils (EO). One of the still unresolved issues is the proper incorporation of these materials into a polymeric matrix. The in situ polymerization seems to be a promising technique, not requiring high temperatures or toxic solvents. Therefore, in this study, the bulk radical polymerization of styrene was investigated in the presence of sodium montmorillonite (NaMMT) and organo-modified montmorillonite (orgMMT) including thyme (TO), oregano (OO), and basil (BO) essential oil. It was found that the hydroxyl groups present in the main ingredients of TO and OO may participate in side retardation reactions leading to lower polymerization rates (measured gravimetrically by the variation of monomer conversion with time) accompanied by higher polymer average molecular weight (measured via GPC). The use of BO did not seem to affect significantly the polymerization kinetics and polymer MWD. These results were verified from independent experiments using model compounds, thymol, carvacrol and estragol instead of the clays. Partially intercalated structures were revealed from XRD scans. The glass transition temperature (from DSC) and the thermal stability (from TGA) of the nanocomposites formed were slightly increased from 95 to 98 °C and from 435 to 445 °C, respectively. Finally, better dispersion was observed when orgMMT was added instead of NaMMT.

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