scholarly journals Processing of (Co)Poly(2-oxazoline)s by Electrospinning and Extrusion from Melt and the Postprocessing Properties of the (Co)Polymers

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 295 ◽  
Author(s):  
Wojciech Wałach ◽  
Natalia Oleszko-Torbus ◽  
Alicja Utrata-Wesołek ◽  
Marcelina Bochenek ◽  
Ewa Kijeńska-Gawrońska ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Molar Mass ◽  
Three Dimensional ◽  
Fused Deposition Modelling ◽  
Processing Conditions ◽  
Structure And Properties ◽  
Scanning Calorimetry ◽  
Gradient Copolymers ◽  
Fused Deposition

Poly(2-oxazoline) (POx) matrices in the form of non-woven fibrous mats and three-dimensional moulds were obtained by electrospinning and fused deposition modelling (FDM), respectively. To obtain these materials, poly(2-isopropyl-2-oxazoline) (PiPrOx) and gradient copolymers of 2-isopropyl- with 2-n-propyl-2-oxazoline (P(iPrOx-nPrOx)), with relatively low molar masses and low dispersity values, were processed. The conditions for the electrospinning of POx were optimised for both water and the organic solvent. Also, the FDM conditions for the fabrication of POx multi-layer moulds of cylindrical or cubical shape were optimised. The properties of the POx after electrospinning and extrusion from melt were determined. The molar mass of all (co)poly(2-oxazoline)s did not change after electrospinning. Also, FDM did not influence the molar masses of the (co)polymers; however, the long processing of the material caused degradation and an increase in molar mass dispersity. The thermal properties changed significantly after processing of POx what was monitored by increase in enthalpy of exo- and endothermic peaks in differential scanning calorimetry (DSC) curve. The influence of the processing conditions on the structure and properties of the final material were evaluated having in a mind their potential application as scaffolds.

scholarly journals Synthesis, crystal structure and thermal properties of poly[bis[μ2-3-(aminomethyl)pyridine]bis(thiocyanato)cobalt(II)]

2021 ◽  
Vol 77 (4) ◽  
pp. 428-432
Author(s):  
Christoph Krebs ◽  
Inke Jess ◽  
Christian Näther
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Hydrogen Bonding ◽  
Thermal Properties ◽  
Powder Diffraction ◽  
Title Compound ◽  
Three Dimensional ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Dimensional Network

The reaction of Co(NCS)2 with 3-(aminomethyl)pyridine as coligand leads to the formation of crystals of the title compound, [Co(NCS)2(C6H8N2)2] n , that were characterized by single-crystal X-ray analysis. In the crystal structure, the CoII cations are octahedrally coordinated by two terminal N-bonded thiocyanate anions as well as two pyridine and two amino N atoms of four symmetry-equivalent 3-(aminomethyl)pyridine coligands with all pairs of equivalent atoms in a trans position. The CoII cations are linked by the 3-(aminomethyl)pyridine coligands into layers parallel to the ac plane. These layers are further linked by intermolecular N—H...S hydrogen bonding into a three-dimensional network. The purity of the title compound was determined by X-ray powder diffraction and its thermal behavior was investigated by differential scanning calorimetry and thermogravimetry.

scholarly journals EKSTRUKSI DAN KARAKTERISASI FILAMEN KOMPOSIT POLYLACTID ACID (PLA) / CARBON NANO TUBE (CNT)

2021 ◽  
Vol 2 (2) ◽  
pp. 12
Author(s):  
Dicky Oktavian ◽  
Budi Arifvianto ◽  
Muslim Mahardika
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Electron Microscope ◽  
Additive Manufacturing ◽  
Fused Deposition Modelling ◽  
Scanning Calorimetry ◽  
Fused Deposition ◽  
Carbon Nano Tube ◽  
Scanning Electron

Dewasa ini teknologi additive manufacturing (AM) mengalami perkembangan yang pesat. Salah satu metode additive manufacturing yang saat ini populer di berbagai belahan dunia adalah metode fused deposition modelling. Prinsip kerja metode ini adalah dengan cara mengekstrusi material filamen polimer yang meleleh dan sudah melewati temperatur rekristalisasinya melalui sebuah nozzle, kemudian produk akan terbentuk secara lapis demi lapis yang dibentuk melalui gerakan relatif dari meja mesin. Dalam pengaplikasiannya, material filamen dapat dibuat dalam bentuk komposit sehingga diperoleh sifat-sifat unik tertentu sehingga dapat digunakan pada bidang-bidang tertentu. Salah satunya adalah pada bidang kesehatan, sebagai pembuatan implan atau jaringan tubuh dengan memiliki kekuatan yang tinggi dan bersifat biodegradable. Pada penelitian ini, dilakukan pembuatan filamen komposit PLA-CNT dengan metode ekstrusi. Proses ekstrusi dilakukan dengan variasi temperatur 143, 145, dan 147ºC dengan memberi tambahan polyethylene glycol (PEG) sebagai plasticizer untuk meningkatkan fleksibilitas dan workability. Hasil pengamatan dengan scanning electron microscope (SEM) mengindikasikan bahwa proses ekstrusi berjalan kurang stabil karena terdapat tekstur permukaan yang bergelombang. Dari pengujian karakterisasi differential scanning calorimetry (DSC), derajat kristalinitas pada variasi ekstrusi filamen PLA-CNT mengalami peningkatan seiring meningkatnya temperatur ekstrusi. Pada pengujian karakterisasi fourier transform infrared spectroscopy (FTIR) terdapat perubahan komposisi kimia pada filamen yang signifikan, yang juga sejalan dengan degradasi sifat mekanis. Variasi filamen dengan temperatur ekstrusi 147ºC memiliki nilai kekerasan paling tinggi yaitu sebesar 40,50 MPa.

scholarly journals Improved Processing and Properties for Polyphenylene Oxide Modified by Diallyl Orthophthalate Prepolymer

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2016
Author(s):  
Honghua Wang ◽  
Qilin Mei ◽  
Yujie Ding ◽  
Zhixiong Huang ◽  
Minxian Shi
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Phase Separation ◽  
Dilution Effect ◽  
Gradual Decrease ◽  
Gel Point ◽  
Dynamic Mode ◽  
Curing Process ◽  
Scanning Calorimetry ◽  
Polyphenylene Oxide

Diallyl orthophthalate (DAOP) prepolymer was investigated as a reactive plasticizer to improve the processability of thermoplastics. The rheology of blends of DAOP prepolymer initiated by 2,3-dimethyl-2,3-diphenylbutane (DMDPB) and polyphenylene oxide (PPO) was monitored during the curing process, and their thermal properties and morphology in separated phases were also studied. Differential scanning calorimetry (DSC) results showed that the cure degree of the reactively plasticized DAOP prepolymer was reduced with increasing PPO due to the dilution effect. The increasing amount of the DAOP prepolymer led to a gradual decrease in the viscosity of the blends and the rheology behavior was consistent with the chemical gelation of DAOP prepolymer in blends. This indicated that the addition of the DAOP prepolymer effectively improved processability. The phase separation occurring during curing of the blend and the transition from the static to dynamic mode significantly influences the development of the morphology of the blend corresponding to limited evolution of the conversion around the gel point.

Development of three-dimensional printing filaments based on poly(lactic acid)/hydroxyapatite composites with potential for tissue engineering

2021 ◽  
pp. 002199832098856
Author(s):  
Marcela Piassi Bernardo ◽  
Bruna Cristina Rodrigues da Silva ◽  
Luiz Henrique Capparelli Mattoso
Keyword(s):  
Tissue Engineering ◽  
Lactic Acid ◽  
Fused Deposition Modeling ◽  
Three Dimensional ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Three Dimensional Printing ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
3D Printed

Injured bone tissues can be healed with scaffolds, which could be manufactured using the fused deposition modeling (FDM) strategy. Poly(lactic acid) (PLA) is one of the most biocompatible polymers suitable for FDM, while hydroxyapatite (HA) could improve the bioactivity of scaffold due to its chemical composition. Therefore, the combination of PLA/HA can create composite filaments adequate for FDM and with high osteoconductive and osteointegration potentials. In this work, we proposed a different approache to improve the potential bioactivity of 3D printed scaffolds for bone tissue engineering by increasing the HA loading (20-30%) in the PLA composite filaments. Two routes were investigated regarding the use of solvents in the filament production. To assess the suitability of the FDM-3D printing process, and the influence of the HA content on the polymer matrix, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were performed. The HA phase content of the composite filaments agreed with the initial composite proportions. The wettability of the 3D printed scaffolds was also increased. It was shown a greener route for obtaining composite filaments that generate scaffolds with properties similar to those obtained by the solvent casting, with high HA content and great potential to be used as a bone graft.

scholarly journals Influence of the Infill Geometry of 3D-Printed Tablets on Drug Dissolution

2021 ◽  
Vol 5 (1) ◽  
pp. 15
Author(s):  
Nuno Venâncio ◽  
Gabriela G. Pereira ◽  
João F. Pinto ◽  
Ana I. Fernandes
Keyword(s):  
Three Dimensional ◽  
Drug Dissolution ◽  
Fused Deposition Modelling ◽  
Three Dimensional Printing ◽  
Preliminary Results ◽  
Fused Deposition ◽  
3D Printed ◽  
Dimensional Printing ◽  
Hot Melt ◽  
Patient Centric

Patient-centric therapy is especially important in pediatrics and may be attained by three-dimensional printing. Filaments containing 30% w/w of theophylline were produced by hot-melt extrusion and printed using fused deposition modelling to produce tablets. Here, preliminary results evaluating the effect of infill geometry (cross, star, grid) on drug content and release are reported.

Investigations of process parameters during dissolution studies of drug loaded 3D printed tablets

2021 ◽  
pp. 095441192199358
Author(s):  
Varun Sharma ◽  
Khaja Moinuddin Shaik ◽  
Archita Choudhury ◽  
Pramod Kumar ◽  
Prateek Kala ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Process Parameters ◽  
Empirical Relation ◽  
Three Dimensional ◽  
Critical Parameters ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
Rate Of Dissolution ◽  
3D Printed ◽  
Percentage Release

The present research paper attempts to study the effect of different process parameters on the dissolution rate during 3D printed tablets. Three-dimensional printing has the potential of serving tailored made tablets to cater personalized drug delivery systems. Fluorescein loaded PVA filaments through impregnation route was used to fabricate tablets based on Taguchi based design of experimentation using Fused Deposition Modelling (FDM). The effect of print speed, infill percentage and layer thickness were analyzed to study the effect on rate of dissolution. Infill percentage followed by print speed were found to be critical parameters affecting dissolution rate. The data analysis provided an insight into the study of interaction among different 3D printing parameters to develop an empirical relation for percentage release of the drug in human body.

Animal orthosis fabrication with additive manufacturing – a case study of custom orthosis for chicken

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wiktoria Maria Wojnarowska ◽  
Jakub Najowicz ◽  
Tomasz Piecuch ◽  
Michał Sochacki ◽  
Dawid Pijanka ◽  
...  
Keyword(s):  
Veterinary Medicine ◽  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Fused Deposition Modelling ◽  
Content Type ◽  
Fused Deposition ◽  
Secondary Objective ◽  
Traditional Manufacturing ◽  
Aided Design

Purpose Chicken orthoses that cover the ankle joint area are not commercially available. Therefore, the main purpose of this study is to fabricate a customised temporary Ankle–Foot Orthosis (AFO) for a chicken with a twisted ankle using computer-aided design (CAD) and three-dimensional (3D) printing. The secondary objective of the paper is to present the specific application of Additive Manufacturing (AM) in veterinary medicine. Design/methodology/approach The design process was based on multiple sketches, photos and measurements that were provided by the owner of the animal. The 3D model of the orthosis was made with Autodesk Fusion 360, while the prototype was fabricated using fused deposition modelling (FDM). Evaluation of the AFO was performed using the finite element method. Findings The work resulted in a functional 3D printed AFO for chicken. It was found that the orthosis made with AM provides satisfactory stiffen and a good fit. It was concluded that AM is suitable for custom bird AFO fabrication and, in some respects, is superior to traditional manufacturing methods. It was also concluded that the presented procedure can be applied in other veterinary cases and to other animal species and other parts of their body. AM provides veterinary with a powerful tool for the production of well-fitted and durable orthoses for animals. Research limitations/implications The study does not include the chicken's opinion on the comfort or fit of the manufactured AFO due to communication issues. Evaluation of the final prototype was done by the researchers and the animal owner. Originality/value No evidence was found in the literature on the use of AM for chicken orthosis, so this study is the first to describe such an application of AM. In addition, the study demonstrates the value of AM in veterinary medicine, especially in the production of devices such as orthoses.

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