Preparation and characterization of chitosan derivatives and their application as flame retardants in thermoplastic polyurethane

2017 ◽  
Vol 167 ◽  
pp. 356-363 ◽  
Author(s):  
Xiaodong Liu ◽  
Xiaoyu Gu ◽  
Jun Sun ◽  
Sheng Zhang
Keyword(s):  
Flame Retardants ◽  
Thermoplastic Polyurethane ◽  
Chitosan Derivatives

scholarly journals A Comprehensive Investigation on 3D Printing of Polyamide 11 and Thermoplastic Polyurethane via Multi Jet Fusion

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2139
Author(s):  
Wei Shian Tey ◽  
Chao Cai ◽  
Kun Zhou
Keyword(s):  
Tensile Strength ◽  
Flexural Strength ◽  
Wear Rate ◽  
Mechanical Performance ◽  
Thermoplastic Polyurethane ◽  
Print Quality ◽  
Polyamide 11 ◽  
Powder Bed

Multi Jet Fusion (MJF) is a recently developed polymeric powder bed fusion (PBF) additive manufacturing technique that has received considerable attention in the industrial and scientific community due to its ability to fabricate functional and complex polymeric parts efficiently. In this work, a systematic characterization of the physicochemical properties of MJF-certified polyamide 11 (PA11) and thermoplastic polyurethane (TPU) powder was conducted. The mechanical performance and print quality of the specimens printed using both powders were then evaluated. Both PA11 and TPU powders showed irregular morphology with sharp features and had broad particle size distribution, but such features did not impair their printability significantly. According to the DSC scans, the PA11 specimen exhibited two endothermic peaks, while the TPU specimen exhibited a broad endothermic peak (116–150 °C). The PA11 specimens possessed the highest tensile strength in the Z orientation, as opposed to the TPU specimens which possessed the lowest tensile strength along the same orientation. The flexural properties of the PA11 and TPU specimens displayed a similar anisotropy where the flexural strength was highest in the Z orientation and lowest in the X orientation. The porosity values of both the PA11 and the TPU specimens were observed to be the lowest in the Z orientation and highest in the X orientation, which was the opposite of the trend observed for the flexural strength of the specimens. The PA11 specimen possessed a low coefficient of friction (COF) of 0.13 and wear rate of 8.68 × 10−5 mm3/Nm as compared to the TPU specimen, which had a COF of 0.55 and wear rate of 0.012 mm3/Nm. The PA11 specimens generally had lower roughness values on their surfaces (Ra < 25 μm), while the TPU specimens had much rougher surfaces (Ra > 40 μm). This investigation aims to uncover and explain phenomena that are unique to the MJF process of PA11 and TPU while also serving as a benchmark against similar polymeric parts printed using other PBF processes.

scholarly journals Preparation and Characterization of Talc Filled Thermoplastic Polyurethane/Polypropylene Blends

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Emi Govorčin Bajsić ◽  
Vesna Rek ◽  
Ivana Ćosić
Keyword(s):  
Thermal Properties ◽  
Thermoplastic Polyurethane ◽  
Mechanical Analysis ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Polypropylene Blends ◽  
Pp Blends ◽  
The Degree Of Crystallinity ◽  
Better Than

The effect of the addition of talc on the morphology and thermal properties of blends of thermoplastic polyurethane (TPU) and polypropylene (PP) was investigated. The blends of TPU and PP are incompatible because of large differences in polarities between the nonpolar crystalline PP and polar TPU and high interfacial tensions. The interaction between TPU and PP can be improved by using talc as reinforcing filler. The morphology was observed by means of scanning electron microscopy (SEM). The thermal properties of the neat polymers and unfilled and talc filled TPU/PP blends were studied by using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The addition of talc in TPU/PP blends improved miscibility in all investigated TPU/T/PP blends. The DSC results for talc filled TPU/PP blends show that the degree of crystallinity increased, which is due to the nucleating effect induced by talc particles. The reason for the increased storage modulus of blends with the incorporation of talc is due to the improved interface between polymers and filler. According to TGA results, the addition of talc enhanced thermal stability. The homogeneity of the talc filled TPU/PP blends is better than unfilled TPU/PP blends.

Bentonite-Based Organoclays as Innovative Flame Retardants Agents for SBS Copolymer

2008 ◽  
Vol 8 (12) ◽  
pp. 6316-6324 ◽  
Author(s):  
M. Comes Franchini ◽  
P. Fabbri ◽  
A. Frache ◽  
G. Ori ◽  
M. Messori ◽  
...  
Keyword(s):  
Flame Retardants ◽  
Morphological Characterization ◽  
Tem Analysis ◽  
Important Functional Property ◽  
Octadecyltrimethylammonium Bromide ◽  
Nitrogen Containing Compounds ◽  
Styrene Butadiene ◽  
Heat Released

Two organophilic bentonites, based on nitrogen-containing compounds, have been synthesised via ion exchange starting from pristine bentonite with octadecyltrimethylammonium bromide (OTAB) and with synthetic melamine-derived N2,N4-dihexadecyl-1,3,5-triazine-2,4,6-triamine (DEDMEL). The chemical and morphological characterization of the organoclays was based on XRD, TEM, Laser Granulometry, X-Ray Fluorescence and CEC capacity. Copoly(styrene-butadiene-styrene)-nanocomposites (SBS-nanocomposites) were obtained by intercalation of the SBS-copolymer into these new organoclays by melt intercalation method. XRD and TEM analysis of the organoclays and of the micro/nano-composites obtained are presented. The effect of the organoclays on the SBS-nanocomposite's flammability properties was investigated using cone calorimeter. An encouraging decrease of 20% in the peak heat released rate (PHRR) has been obtained confirming the important role of melamine's based skeleton and its derived organoclays to act as effective fire retardants and for the improvement of this important functional property in SBS copolymers.

Foaming and thermal characteristics of bio-based polylactic acid–thermoplastic polyurethane blends

2018 ◽  
Vol 54 (6) ◽  
pp. 931-955 ◽  
Author(s):  
Mohsen Barmouz ◽  
Amir Hossein Behravesh
Keyword(s):  
Polylactic Acid ◽  
High Cell Density ◽  
Thermoplastic Polyurethane ◽  
Research Work ◽  
Thermal Characteristics ◽  
High Cell ◽  
Foam Expansion ◽  
Foaming Process ◽  
Cell Densities

This paper reports a research work on characterization of foamed biocompatible polylactic acid–thermoplastic polyurethane blends in terms of microstructural, thermal, and physical properties. The brittleness of the polylactic acid is compensated via blending with an elastoplastic phase of thermoplastic polyurethane. A range of low bulk density foam with a high cell density was produced in a solid state foaming process. Addition of thermoplastic polyurethane phase acted against the cell growth and thus foam expansion, apparently due to its inherent lower storage modulus, which weakens the polymer matrix and leads to gas escape phenomenon. Evaluation of thermal properties showed a tangible effect of blending and foaming process on crystallization of the specimens, which confirmed that the sensitivity of polylactic acid’s crystallinity to CO2 gas saturation was reduced as a result of thermoplastic polyurethane addition. Measurement of cell diameters and cell densities of the foamed samples demonstrated formation of the fine closed cells structure as a result of suitable foaming parameters that were able to deal with stiffness and strength of the polymeric matrix.

Characterization of the Aniline.DBSA/Thermoplastic Polyurethane Blends for the Thermo-Mechanical and Electro-Mechanical Properties

2021 ◽  
Vol 875 ◽  
pp. 96-103
Author(s):  
Ayesha Afzal ◽  
Iqra Abdul Rashid ◽  
H.M. Faizan Shakir ◽  
Asra Tariq
Keyword(s):  
Mechanical Properties ◽  
Thermoplastic Polyurethane ◽  
Strain Sensors ◽  
Sem Images ◽  
Dynamic Mechanical Thermal Analyzer ◽  
Thermal Analyzer ◽  
Uniform Dispersion ◽  
Polymerization Method

Conducting polymer blends Polyaniline-Dodecylbenzene sulfonic acid (Pani.DBSA) and thermoplastic polyurethane (TPU) were prepared using in-situ emulsion polymerization method by dissolving both components in DMF. Ani.DBSA/TPU blends were prepared with different compositions 20/80, 30/70, 40/60 and 50/50 wt%. Theses blends have good conducting and mechanical properties. Blends were characterized by Potentiostate, Thermogravimetric analysis (TGA), Infrared spectroscopy (FTIR) and Dynamic mechanical thermal analyzer (DMTA). The electrical conductivity increases up to 30 wt% loading of aniline.DBSA after that it decreases gradually. The uniform dispersion of aniline.DBSA showed in SEM images which is the indication of a strong connection between aniline.DBSA and TPU which increase the conductivity. These blends can be used as strain sensors.

scholarly journals Design of Soft Grippers with Modular Actuated Embedded Constraints

Robotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 105
Author(s):  
Gabriele Maria Achilli ◽  
Maria Cristina Valigi ◽  
Gionata Salvietti ◽  
Monica Malvezzi
Keyword(s):  
Finite Element Method ◽  
Flat Surface ◽  
Thermoplastic Polyurethane ◽  
Fem Analysis ◽  
Robotic Hand ◽  
Main Design ◽  
Grasping And Manipulation ◽  
Static Simulation

Underactuated, modular and compliant hands and grippers are interesting solutions in grasping and manipulation tasks due to their robustness, versatility, and adaptability to uncertainties. However, this type of robotic hand does not usually have enough dexterity in grasping. The implementation of some specific features that can be represented as “embedded constraints” allows to reduce uncertainty and to exploit the role of the environment during the grasp. An example that has these characteristics is the Soft ScoopGripper a gripper that has a rigid flat surface in addition to a pair of modular fingers. In this paper, we propose an upgraded version of the Soft ScoopGripper, developed starting from the limits shown by the starting device. The new design exploits a modular structure to increase the adaptability to the shape of the objects that have to be grasped. In the proposed device the embedded constraint is no rigid neither unactuated and is composed of an alternation of rigid and soft modules, which increase versatility. Moreover, the use of soft material such as thermoplastic polyurethane (TPU) reduces the risk of damage to the object being grasped. In the paper, the main design choices have been exploited and a finite element method (FEM) analysis through static simulation supports a characterization of the proposed solution. A complete prototype and some preliminary tests have been presented.

Sign in / Sign up

Export Citation Format

Share Document