Thermophysical and Mechanical Properties of β-Tricalcium Phosphate Reinforced Polyhydroxybutyrate and Polyhydroxybutyrate-Co-Hydroxyvalerate Composites

2007 ◽  
Vol 334-335 ◽  
pp. 1217-1220 ◽  
Author(s):  
Ya Liu ◽  
Min Wang

Two series of bioactive and biodegradable composite materials consisting of particulate β-tricalcium phosphate (β-TCP) and polyhydroxybutyrate (PHB) and its copolymer polyhydroxybutyrate-co-hydroxyvalerate (PHBV) were produced and investigated for bone tissue repair. A manufacturing route employing injection moulding was established for producing the biomedical composites. In the process, plates of composites containing 10%, 20%, 30% or 40% by volume of micro-sized TCP particles were successfully injection moulded for both TCP/PHB and TCP/PHBV composites. Thermal properties of as-produced TCP/PHB and TCP/PHBV composites were systematically evaluated using differential scanning calorimetry (DSC). The mechanical performance of TCP/PHB and TCP/PHBV composites was assessed using dynamic mechanical analysis (DMA).

MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2689-2694
Author(s):  
Karla A. Gaspar-Ovalle ◽  
Juan V. Cauich-Rodriguez ◽  
Armando Encinas

ABSTRACTNanofibrous mats of poly ε-caprolactone (PCL) were fabricated by electrospinning. The nanofiber structures were investigated and characterized by scanning electron microscope, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, static water-contact-angle analysis and mechanical properties. The results showed that the nanofibrous PCL is an ideal biopolymer for cell adhesion, owing to its biocompatibility, biodegradability, structural stability and mechanical properties. Differential scanning calorimetry results showed that the fibrous structure of PCL does not alter its crystallinity. Studies of the mechanical properties, wettability and degradability showed that the structure of the electrospun PCL improved the tensile modulus, tensile strength, wettability and biodegradability of the nanotemplates. To evaluate the nanofibrous structure of PCL on cell adhesion, osteoblasts cells were seeded on these templates. The results showed that both adhesion and proliferation of the cells is viable on these electrospun PCL membranes. Thus electrospinning is a relatively inexpensive and scalable manufacturing technique for submicron to nanometer diameter fibers, which can be of interest in the commodity industry.


Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2636
Author(s):  
Tomasz M. Majka ◽  
Oskar Bartyzel ◽  
Konstantinos N. Raftopoulos ◽  
Joanna Pagacz ◽  
Krzysztof Pielichowski

Pyrolysis of the polypropylene/montmorillonite (PP/OMMT) nanocomposites allows for recovery of the filler that can be then re–used to produce PP/pyrolyzed MMT (PMMT) nanostructured composites. In this work, we discuss the thermal properties of PP/PMMT composites investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It has been found that effect of PMMT (5 wt. % and 10 wt. %) on matrix thermal stability occurs at temperatures above 300 °C. Addition of 5 wt. % and 10 wt. % of PMMT into polypropylene system gave good stabilization effect, as confirmed by the overall stabilization effect (OSE) values, which increased by 4% and 7%, respectively, compared to the control sample (PP). Interestingly, the presence of 1 wt. % and 3 wt. % of pyrolyzed clay stabilizes the system better than the same concentrations of organoclay added into polypropylene melt. DSC data revealed that pyrolyzed clay has still the same tendency as organoclay to enhance formation of the α and β crystalline PP phases only. The pyrolyzed MMT causes an improvement of the modulus in the glassy as well as rubbery regions, as confirmed by DMA results.


Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5789
Author(s):  
Olga Mysiukiewicz ◽  
Mateusz Barczewski ◽  
Arkadiusz Kloziński

Polylactide-based composites filled with waste fillers due to their sustainability are a subject of many current papers, in which their structural, mechanical, and thermal properties are evaluated. However, few studies focus on their behavior in low temperatures. In this paper, dynamic and quasi-static mechanical properties of polylactide-based composites filled with 10 wt% of linseed cake (a by-product of mechanical oil extraction from linseed) were evaluated at room temperature and at −40 °C by means of dynamic mechanical analysis (DMA), Charpy’s impact strength test and uniaxial tensile test. It was found that the effect of plasticization provided by the oil contained in the filler at room temperature is significantly reduced in sub-zero conditions due to solidification of the oil around −18 °C, as it was shown by differential scanning calorimetry (DSC) and DMA, but the overall mechanical performance of the polylactide-based composites was sufficient to enable their use in low-temperature applications.


1986 ◽  
Vol 76 ◽  
Author(s):  
C. W. Wilkins ◽  
H. E. Bair ◽  
M. G. Chan ◽  
R. S. Hutton

ABSTRACTWe have studied some of the physical and mechanical properties of cyclized polybutadiene (CBR) dielectrics by dynamic mechanical analysis, thermal mechanical analysis, thermogravimetry, infrared analysis, and differential scanning calorimetry. Of interest is the difference in properties between thin (<30 μm) films which have been cured under vacuum and those which have been cured in air. Our results indicate that curing under vacuum prevents oxidation and reduces crosslinking. Vacuum cured films have 20% smaller moduli and 200 lower glass transition temperature than do films produced in air.


2016 ◽  
Vol 29 (10) ◽  
pp. 1139-1147 ◽  
Author(s):  
Zi Sang ◽  
Tiantian Feng ◽  
Wenbin Liu ◽  
Jun Wang ◽  
Mehdi Derradji

A new series of aniline and aniline-mixed tetrafunctional fluorene-based oxazine monomers were synthesized using 2,7-hydroxy-9,9-bis-(4-hydroxyphenyl) fluorene, paraformaldehyde, and primary amines (including aniline or aniline mixed with n-butylamine or n-octylamine composition). Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy were used to characterize the structure of the monomers. The copolymers were obtained by adding the monomers into a typical monofunctional polybenzoxazine (phenol-aniline-based benzoxazine). Differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis were performed to study the thermal properties of the copolymers. The copolymers exhibited high glass transition temperature values (164–201°C). A good thermal stability was also obtained with a 5% weight loss temperature over 355°C and high char yields at 800°C (42–50%).


2003 ◽  
Vol 767 ◽  
Author(s):  
A. Tregub ◽  
G. Ng ◽  
M. Moinpour

AbstractSoak of polyurethane-based CMP pads in tungsten slurry and de-ionized water and its effect on retention of thermal and mechanical properties of the pads was studied using Dynamic Mechanical Analysis (DMA), Thermal Mechanical Analysis (TMA), Thermal Gravimetric Analysis (TGA), and Modulated Differential Scanning Calorimetry (MDSC). Simultaneous cross-linking and plastisizing due to soak were established using DMA and MDSC analysis. The stable operating temperature range and its dependence on soak time were determined using TMA analysis. Substantial difference in diffusion behavior of the “soft” and “hard” pads was discovered: diffusion into the hard pads followed Fickian law [1], while diffusion into the multi-layer soft pads was dominated by the fast filling of the highly porous pad surface with liquid.During a traditional CMP process, which involves application of polishing pads and slurry, the pad properties can be substantially and irreversibly changed as the result of slurry/rinse water absorption.The retention of the pad properties after exposure was monitored using such thermal and mechanical techniques, as Thermal Mechanical Analysis (TMA), Dynamical Mechanical Analysis (DMA), Modulated Differential Scanning Calorimetry (MDSC), Thermal Gravimetric Analysis (TGA).


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
E. Irzmańska ◽  
M. Jurczyk-Kowalska ◽  
M. Bil ◽  
M. Płocińska

AbstractThe study involved laminated nylon and viscose nonwovens, both perforated and non-perforated, with a view to using them for packaging of powders in mineral warmers. The nonwovens were examined in terms of morphology as well as tensile strength in dry and wet states. Thermal properties were determined by differential scanning calorimetry. Dynamic mechanical analysis was carried out in a broad range of temperatures. Surface wettability and water vapor permeability were assessed. The findings were analyzed to determine the utility of the studied materials as mineral warmer packaging materials in cold work or living environments.


2020 ◽  
Vol 22 (4) ◽  
pp. 10-16
Author(s):  
Gvlmira Hasan ◽  
Dilhumar Musajan ◽  
Gong-bo Hou ◽  
Mingyu He ◽  
Ying Li ◽  
...  

AbstractLignin was used to study the mechanical properties and thermal stability of polymers. The lignin was blended with three kinds of polymers, and the addition of lignin was 0.5 wt%. Under the condition of thermal oxidation, the thermal stability of lignin/polymer samples varies with the structure of lignin. The effects of lignin on the mechanical properties and thermal stability of the polymers were investigated by oxidation induction time (OIT), rheological properties, mechanical properties and differential scanning calorimetry (DSC). The results show that the effect of lignin on the thermal properties of polymer samples is 2~3°C. It can be inferred that lignin can effectively improve the interaction between polymer molecular chain segments, and improve the crystallization rate and rigidity to a certain extent, so it can be seen that lignin has good compatibility and thermal stability.


2019 ◽  
Vol 54 (3) ◽  
pp. 345-362 ◽  
Author(s):  
Elena Rusu

This study describes the changes in some properties of two series of nylon 612/TiO2 composites by varying filler type (untreated and treated) and content (up 8.0 wt.%). The samples preparation by simultaneous anionic copolymerization-molding process ensures a good dispersion of the filler in matrix. Differential scanning calorimetry, thermogravimetrical analysis, static mechanical testing, dynamic mechanical analysis and scanning electron microscopy allowed to investigate the effects of filler loading on the mechanical, thermal and morphological characteristics of the samples and revealed the importance of filler treatment on the composites behaviour. The semicrystalline character has been proved by differential scanning calorimetry (only a single melting peak is present) and wide-angle X-ray diffraction (two reflexion plane with d-spacing of 0.4311 and 0.3817 nm appear). At the same filler content, the difference ΔHm1–ΔHc was higher for the samples with treated filler. The lower Tm,α(2) in comparison with Tm,α(1) revealed a modification of the nucleation process during crystallization. The main mass loss of the samples occurred between 277 and 550℃. The addition of the filler leads to the improvement of flexural strength and flexural modulus in comparison with neat copolymer. Incorporating 8.0 wt.% treated filler, the Tg value increases by about 11.0%, reaching 61.0℃.


2020 ◽  
Vol 869 ◽  
pp. 280-295
Author(s):  
Andrei Didenko ◽  
Danila Kuznetcov ◽  
Gleb Vaganov ◽  
Valentina Smirnova ◽  
Elena Popova ◽  
...  

The series of compositions containing thermodynamically incompatible flexible blocks of aliphatic polyesters and rigid blocks of aromatic bis (urethane) imides in the volume of polymers was obtained on the basis of multiblock (segmented) poly (urethane-imides) and related aromatic polyimides. The series includes segmented poly (urethane-imides) with different relative content of flexible and rigid blocks, non-segregating mixtures of poly (urethane-imides) and thermoplastic partially crystalline polyimide, statistical copolymers of poly (urethane-imide) with imide, and non-segregating mixtures of statistical copolymers with thermoplastic polyimide. The derived polymer systems were studied using thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The deformation and strength properties of film samples are determined. It is shown that the properties of the studied polymers change as their content of imides blocks increases, and the transition from thermoplastic poly (urethane-imide) elastomers to thermoplastic polyimides is observed.


Sign in / Sign up

Export Citation Format

Share Document