Thermal and Mechanical Properties of Acrylonitrile-Butadiene Rubber Modified Polybenzoxazine as Frictional Materials

2015 ◽  
Vol 659 ◽  
pp. 511-515 ◽  
Author(s):  
Jakkrit Jantaramaha ◽  
Chanchira Jubsilp ◽  
Sarawut Rimdusit
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Storage Modulus ◽  
Mechanical Analysis ◽  
Exothermic Peak ◽  
Butadiene Rubber ◽  
Scanning Calorimetry ◽  
Acrylonitrile Butadiene Rubber ◽  
Frictional Composites

Frictional composites based on polybenzoxazine (PBA-a) and acrylonitrile-butadiene rubber (NBR) are developed in this study. Mechanical, thermal and tribological properties of the PBA-a/NBR composites at 0, 2, 5, 10 and 15wt% of NBR particle contents are evaluated. Curing behaviors of the NBR-benzoxazine molding compounds are examined by differential scanning calorimetry to show an exothermic peak of about 222°C compared with that of the benzoxazine resin, i.e. 232°C suggesting curing acceleration of the benzoxazine resin due to the presence of the NBR particles. The storage modulus of the NBR-filled PBA-a is observed to systematically decrease from 5.2 GPa of the neat PBA-a to 2.8 GPa with an addition of 15wt% of the rubber particles. Glass transition temperature (Tg) of the composites evaluated by dynamic mechanical analysis increases with increasing of NBR particle contents, i.e. from 172°C for PBA-a to 186°C for PBA-a/15wt% NBR. Furthermore, the friction coefficients of the composites with 2wt% NBR are determined to be 0.603 for static type and 0.528 for kinetic type. Those values are improved from the value of 0.597 and 0.475 for unmodified polybenzoxazine, respectively. Therefore, the obtained outstanding properties, i.e. storage modulus, glass transition temperature and friction coefficient make the polybenzoxazine composites highly attractive to be utilized as friction materials.

Dynamic mechanical behaviour of kevlar and carbon-kevlar hybrid fibre reinforced polymer composites

2020 ◽  
pp. 095440622097060
Author(s):  
Pragati Priyanka ◽  
Harlal Singh Mali ◽  
Anurag Dixit
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Dynamic Mechanical Analysis ◽  
Storage Modulus ◽  
Composite Laminates ◽  
Mechanical Analysis ◽  
Textile Composites ◽  
Elastic Behaviour ◽  
Dynamic Mechanical

Comprehensive experimental results of dynamic mechanical analysis (DMA) of polymer reinforced textile composites are presented in the current investigation. Plain and 2x2 twill woven multilayer fabrics of monolithic kevlar and hybrid carbon-kevlar (C-K) are reinforced into the thermoset polymer matrix. Kevlar/epoxy and C-K/epoxy composite laminates are fabricated using an in-house facility of the vacuum-assisted resin infusion process. Variation of the visco-elastic behaviour (storage modulus, damping factor and glass transition temperature, Tg) along with time, temperature and frequency is studied for the composites. Dynamic mechanical analysis is performed under temperature sweep with frequency ranging from 1-50 Hz. Results depict the effect of inter yarn hybridisation of carbon with kevlar yarns on the storage modulus, damping performance, and creep behaviour of dry textile composites. Temperature swept dynamic characterisation is also performed to evaluate the degradation and damping performance of the composite laminates soaked in the deionised water at glass transition temperature Tg, ½ Tg, and ¾ Tg. The morphological study has been performed post the dynamic mechanical analysis using field emission scanning electron microscope.

scholarly journals Review of Recent Developments of Glass Transition in PVC Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4336
Author(s):  
Jolanta Tomaszewska ◽  
Tomasz Sterzyński ◽  
Aneta Woźniak-Braszak ◽  
Michał Banaszak
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Thermomechanical Analysis ◽  
Mechanical Analysis ◽  
Temperature Dependent ◽  
Scanning Calorimetry ◽  
Recent Developments ◽  
Dielectric Thermal Analysis ◽  
The Impact

This review addresses the impact of different nanoadditives on the glass transition temperature (Tg) of polyvinyl chloride (PVC), which is a widely used industrial polymer. The relatively high Tg limits its temperature-dependent applications. The objective of the review is to present the state-of-the-art knowledge on the influence of nanofillers of various origins and dimensions on the Tg of the PVC. The Tg variations induced by added nanofillers can be probed mostly by such experimental techniques as thermomechanical analysis (TMA), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and dielectric thermal analysis (DETA). The increase in Tg is commonly associated with the use of mineral and carbonaceous nanofillers. In this case, a rise in the concentration of nanoadditives leads to an increase in the Tg due to a restraint of the PVC macromolecular chain’s mobility. The lowering of Tg may be attributed to the well-known plasticizing effect, which is a consequence of the incorporation of oligomeric silsesquioxanes to the polymeric matrix. It has been well established that the variation in the Tg value depends also on the chemical modification of nanofillers and their incorporation into the PVC matrix. This review may be an inspiration for further investigation of nanofillers’ effect on the PVC glass transition temperature.

scholarly journals Pharmaceutical Amorphous Organic Materials Characterization by Using the Differential Scanning Calorimetry and Dynamic Mechanical Analysis

2011 ◽  
Vol 6 (2) ◽  
pp. 91-95
Author(s):  
Ion Dranca ◽  
Igor Povar ◽  
Tudor Lupascu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Dynamic Mechanical Analysis ◽  
Mechanical Analysis ◽  
Relaxation Processes ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Β Relaxation

This research has been carried out in order to demonstrate the use of differential scanning calorimetry (DSC) in detecting and measuring α- and β-relaxation processes in amorphous pharmaceutical systems. DSC has been employed to study amorphous samples of poly (vinylpyrrolidone) (PVP), indomethacin (InM), and ursodeoxycholic acid (UDA) that are annealed at temperature (Ta) around 0.8 of their glass transition temperature (Tg). Dynamic mechanical analysis (DMA) is used to measure β- relaxation in PVP. Yet, the DSC has been used to study the glassy indomethacin aged at 0 and -10 oC for periods of time up to 109 and 210 days respectively. The results demonstrate the emergence of a small melting peak of the α-polymorph after aging for 69 days at 0°C and for 147 days at -10°C (i.e., ~55°C below the glass transition temperature) that provides evidence of nucleation occurring in the temperature region of the β-relaxation.

Adamantane-Modified Polyurethanes: Effect of Hydroxy Group of Adamantane on the Properties of Polyurethanes

2015 ◽  
Vol 1110 ◽  
pp. 92-95 ◽  
Author(s):  
Ze Ren Lau ◽  
Sau Leng Sin ◽  
Hong Yan ◽  
Jian Wei Xu
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Dynamic Mechanical Analysis ◽  
Storage Modulus ◽  
Low Temperatures ◽  
Mechanical Analysis ◽  
Synthesis And Characterization ◽  
Hydroxy Groups

The paper describes synthesis and characterization of adamantane-modified polyurethanes (PU). The study shows that the number of hydroxy groups of adamantane additives plays a signifiant role in tuning polyurethane's properties. PU modified with adamantanetriol has relatively higher glass transition temperature than these with adamantanediol as an additive. Dynamic mechanical analysis (DMA) of PU with 0.5% adamantanetriol shows significant improvement in storage modulus and larger hardness than pure PU at low temperatures. In contrast, adamantanediol-modified PU exhibits lower storage modulus and smaller hardness than pure PU film. These remarkabe differences between two types of admantane-modified PUs originate from the low reactivity of adamantanediol as well as the formation of crosslinked structures in the presence of adamantanetriol.

scholarly journals The Effect of Extender Particle Size on the Glass Transition Temperature of Model Epoxy Coatings

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 196 ◽  
Author(s):  
Muhammad Ahsan Bashir ◽  
Martin Gjerde Jakobsen ◽  
Vivian Beate Farstad
Keyword(s):  
Particle Size ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Mechanical Analysis ◽  
Organic Coatings ◽  
Particle Sizes ◽  
Scanning Calorimetry ◽  
Epoxy Amine ◽  
Thermosetting Epoxy

Inorganic extenders are important constituents of 2K thermosetting epoxy-amine coatings and their physical properties play an important role in the final properties of the organic coatings. The effects of extender particle size and loading (i.e., the amount of extender in component A or in the total formulation) on the glass transition temperature (Tg) of model epoxy-amine coatings were studied in this work with differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The obtained results show that the particle size and loading of feldspar particles (from 25 wt% to 70 wt%) do not influence the glass transition temperature of the model epoxy-amine coating significantly. In general, the smaller the particle size the lower the glass transition temperature of the coating but this depression in Tg seems negligible when seen relative to the change in extender particle size. Similar observations are reported for two model coatings having the same lamda (Λ) value but with silica of very different particle sizes (i.e., nanosilica and micron sized silica).

Effects of Nano-Silica Addition and Reactive Diluent Addition on Dynamic Mechanical Properties of Epoxy Nanocomposites

2013 ◽  
Vol 853 ◽  
pp. 46-52
Author(s):  
Huey Ling Chang ◽  
Chih Ming Chen
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Storage Modulus ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Reactive Diluent ◽  
Dynamic Mechanical ◽  
Silica Nanopowder

Epoxy resin nanocomposite samples containing 0~3wt.% reactive diluent and 0~3wt.% silica nanopowder are prepared. The preparation process is presented for solvent-free and greenmanufacturing. The storage modulus, loss modulus and glass transition temperature of the various samples are then evaluated via Dynamic Mechanical Analysis (DMA). For samples containing 0wt.% and 3wt.% reactive diluent, respectively, 3wt.% nanoSiO2 addition is found to increase the storage modulus by 51.06 % and 22.22 %, respectively. In addition, it is found that the loss modulus is determined principally by the level of SiO2 addition, whereas the glass transition temperature is determined mainly by the level of reactive diluent addition.

Determining the Glass Transition Temperature of an Epoxy Siloxane Composite by Thermal Analysis Methods

2018 ◽  
Vol 45 (6) ◽  
pp. 269-274
Author(s):  
V.S. Osipchik ◽  
Yu.V. Olikhova ◽  
L.Kh. Nguen ◽  
G.A. Lushcheikin ◽  
V.M. Aristov
Keyword(s):  
Thermal Analysis ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Three Dimensional ◽  
Thermomechanical Analysis ◽  
Mechanical Analysis ◽  
Strength Properties ◽  
Dimensional Structure ◽  
Scanning Calorimetry

Thermomechanical analysis, dynamic mechanical analysis, differential scanning calorimetry, and dielectric thermal analysis were used to determine the glass transition temperature of hot-curing epoxy siloxane composites. The effect of polymethylphenylsiloxane resin on the parameters of the three-dimensional structure and on the deformation and strength properties of epoxy novolac resin during curing by 4,4′-diaminodiphenylmethane was established.

scholarly journals Effect of Filler on Glass Transition of Asphalt Mastics

2012 ◽  
Vol 5 ◽  
pp. 376-381 ◽  
Author(s):  
Meng Guo ◽  
Yi Qiu Tan ◽  
Lei Zhang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Volume Fraction ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Filler Volume Fraction ◽  
Asphalt Mastics ◽  
Dsc Method

A study has been carried out of the glass transition of fifteen asphalt-filler mastics in three different filler types. The dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) method were used. The results show that DMA method can measure asphalt Tg of asphalt-filler mastics more accurately than DSC; The glass transition temperature measured by DMA is generally higher by 20~40oC than that measured by DSC; The glass transition temperature of the asphalt-filler mastics increase with the increase of the filler volume fraction, and andesite is the most sensitive; When the volume fraction of filler is greater than 0.5, the enhance capability of glass transition temperature of asphalt-filler mastics is in the order of andesite > granite > limestone; while the volume fraction of filler is smaller than 0.2, the enhance capability is in the order of granite > limestone > andesite.

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