Mechanical and thermal properties of glass fiber–vinyl ester resin composite for pipeline repair exposed to hot-wet conditioning

2016 ◽  
Vol 51 (11) ◽  
pp. 1605-1617 ◽  
Author(s):  
Md Shamsuddoha ◽  
Luke P Djukic ◽  
Md Mainul Islam ◽  
Thiru Aravinthan ◽  
Allan Manalo
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Glass Fiber ◽  
Vinyl Ester ◽  
Resin Composite ◽  
Oil And Gas Industry ◽  
Mechanical And Thermal Properties ◽  
Fiber Reinforced

Fiber-reinforced composites are a well-recognized option for repair and rehabilitation of the pipelines for the oil and gas industry. Infilled composite sleeve system provides an effective rehabilitation solution, where the sleeve acts as prime reinforcement without any direct contact with steel. However, the long-term performance of the repair is dependent, in part, on the effect of hygrothermal ageing of the composites. In this publication, glass transition temperature and mechanical properties are compared for glass-fiber reinforced vinyl ester composite, both as-manufactured and after hot-wet conditioning at 80℃. The tensile and shear strength reduced substantially during conditioning, whilst the elastic modulus was relatively stable. The average glass transition temperature of the composite dropped from the as-manufactured value of 110℃ to 97℃ and 101℃, after 1000 and 3000 h of conditioning, respectively, indicating that it is stable and that the composite is suitable for use as a pipeline repair material operating at 80℃. The results indicate that a 1000 h conditioning period, specified as a minimum period in ISO/TS 24817 is suitable for representing long-term properties for stiffness-based designs for the composite material and conditioning temperature investigated.

scholarly journals Long-Term Physical (In)Stability of Spray-Dried Amorphous Drugs: Relationship with Glass-Forming Ability and Physicochemical Properties

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 425 ◽  
Author(s):  
Edueng ◽  
Bergström ◽  
Gråsjö ◽  
Mahlin
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Physicochemical Properties ◽  
Physical Stability ◽  
Glass Forming Ability ◽  
Melt Quenching ◽  
Glass Forming ◽  
Spray Dried

This study shows the importance of the chosen method for assessing the glass-forming ability (GFA) and glass stability (GS) of a drug compound. Traditionally, GFA and GS are established using in situ melt-quenching in a differential scanning calorimeter. In this study, we included 26 structurally diverse glass-forming drugs (i) to compare the GFA class when the model drugs were produced by spray-drying with that when melt-quenching was used, (ii) to investigate the long-term physical stability of the resulting amorphous solids, and (iii) to investigate the relationship between physicochemical properties and the GFA of spray-dried solids and their long-term physical stability. The spray-dried solids were exposed to dry (<5% RH) and humid (75% RH) conditions for six months at 25 °C. The crystallization of the spray-dried solids under these conditions was monitored using a combination of solid-state characterization techniques including differential scanning calorimetry, Raman spectroscopy, and powder X-ray diffraction. The GFA/GS class assignment for 85% of the model compounds was method-dependent, with significant differences between spray-drying and melt-quenching methods. The long-term physical stability under dry condition of the compounds was predictable from GFA/GS classification and glass transition and crystallization temperatures. However, the stability upon storage at 75% RH could not be predicted from the same data. There was no strong correlation between the physicochemical properties explored and the GFA class or long-term physical stability. However, there was a slight tendency for compounds with a relatively larger molecular weight, higher glass transition temperature, higher crystallization temperature, higher melting point and higher reduced glass transition temperature to have better GFA and better physical stability. In contrast, a high heat of fusion and entropy of fusion seemed to have a negative impact on the GFA and physical stability of our dataset.

The Effects of Chemical Resistance for Nanocomposite Materials via Nano-Silica Addition into Glass Fiber/Epoxy

2013 ◽  
Vol 853 ◽  
pp. 28-33
Author(s):  
Huey Ling Chang ◽  
Chih Ming Chen ◽  
Kung Liang Lin ◽  
Bor Kae Chang
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Glass Fiber ◽  
Epoxy Resin ◽  
Storage Modulus ◽  
Chemical Resistance ◽  
Dynamic Mechanical Properties ◽  
Silica Nanopowder

Nanocomposite samples containing epoxy resin, glass fiber and 0~2 wt.% SiO2 nanopowder are prepared. The effects of SiO2 addition on the chemical resistance, glass transition temperature (Tg) and dynamic mechanical properties of the various samples are then observed. The chemical resistance of the nanocomposite specimens is compared with that of pure glass fiber/epoxy composite specimens when tested in acetone. The results show that the addition of 2 wt.% SiO2 increases the value of storage modulus by 1646MPa compared to that of the sample containing no silica nanopowder. Following immersion in acetone, all the nanocomposite specimen storage modulus decreased, but the addition of SiO2 reduced the decline, where the 2 wt. % samples decrease from 11.76% reduction to 0.84% and no significant change in the Tg compared to that of the sample with no silica nanopowder. Therefore, the experimental results indicate that 2 wt.% SiO2 addition is beneficial in improving chemical resistance, glass transition temperature, and dynamic mechanical properties of epoxy resin / glass fiber nanocomposites.

Organomodified Clay and its Influence on Thermal and Fire Behaviors of Clay/Fire Retardant/Poly Vinyl Ester Composites

2015 ◽  
Vol 659 ◽  
pp. 468-473 ◽  
Author(s):  
K. R. Vishnu Mahesh ◽  
H.N. Narasimha Murthy ◽  
B.E. Kumara Swamy ◽  
N. Raghavendra ◽  
M. Krishna
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Synergistic Effect ◽  
Vinyl Ester ◽  
Fire Retardant ◽  
Fire Retardants ◽  
Limiting Oxygen Index ◽  
Twin Screw ◽  
Cloisite 15A

The objective of this research was to examine the synergistic effect of organomodified nanoclay and fire retardants on the thermal decomposition, glass transition temperature and fire retardation behaviour of nanoclay/Poly vinyl ester composites. The two nanoclays such as Cloisite-15A and Cloisite-Na are used along with two fire retardants as Aluminium Tri Hydroxide (ATH) and Magnesium Hydroxide (MH) in the present study. The nanoclay/fire retardants were dispersed in poly vinyl ester using twin screw extrusion. TEM and AFM of nanoclay/Poly vinyl ester specimens revealed that 4 wt% Cloisite-15A/Poly vinyl ester exhibited exfoliation and distribution of nanoclay which were superior to that of Cloisite-Na/Poly vinyl ester. The synergistic effect of Cloisite-15A and 30 % ATH increased glass transition temperature by 18 % and reduced thermal degradation by 47 % and Limiting Oxygen Index (LOI) by 52 % when compared with that of Poly vinyl ester after the curing process in all the cases.

Evaluation of Influence of the Addition Nanofillers on the Mechanical and Thermal Properties Terpolymers Ester-Ether-Amide

2014 ◽  
Vol 59 (1) ◽  
pp. 237-239
Author(s):  
A. Kozłowska ◽  
M. Piatek-Hnat
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Thermoplastic Elastomer ◽  
Nanocomposite Materials ◽  
Polymeric Matrix ◽  
Mechanical And Thermal Properties ◽  
Positive Effect

Abstract The results of studies of mechanical and thermal properties of synthesized elastomeric nanocomposites have been presented. An elastomeric multiblock terpoly(ester-b-ether-b-amide)s as polymeric matrix and nanoparticles SiO2 i TiO2 used as fillers. It was shown that the introduction of multiblock thermoplastic elastomer matrix of SiO2 and TiO2 nanoparticles allows to obtain nanocomposite materials with improved mechanical properties compared to the terpolymer before modification. An increase in glass transition temperature, which has a positive effect for the processing of terpolymers.

scholarly journals Dynamic Moduli of Polybutylene Terephthalate Glass Fiber Reinforced in High-Temperature Environments

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 483
Author(s):  
Carmelo Gómez ◽  
Jorge Mira ◽  
F.J. Carrión-Vilches ◽  
Francisco Cavas
Keyword(s):  
Glass Transition ◽  
High Temperature ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Glass Fiber ◽  
Storage Modulus ◽  
Fiber Content ◽  
Polybutylene Terephthalate ◽  
Dynamic Moduli ◽  
Over Time

The aim of this work was to show the evolution over time of the dynamic moduli in components made of Polybutylene Terephthalate reinforced with glass fiber when they are held to temperatures close to the glass transition temperature over time. For this purpose, PBT samples reinforced with short, glass fibers of Ultradur® material with 0%, 20%, and 50% in weight content were tested. Dynamic moduli showed an increment with glass fiber content showing a nonlinear behavior with the temperature. The evolution of storage modulus was depicted by means of a modified law of mixtures with an effectiveness factor depending on temperature and fiber content, whereas the evolution over time was obtained with a time–temperature transformation generated with the TTS Data Analysis software of TA-instruments for a given temperature. Storage modulus showed a linear relationship with glass fiber content when components were held to temperatures near to their respective glass transition temperature, obtained from the maximum of loss modulus curve with temperature. In summary, the value and evolution of dynamic moduli of PBT samples improved with glass fiber content, allowing us to increase the durability of components when they are submitted to high-temperature environments.

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