Gas environment effect on cavitation damage in stretched polyvinylidene fluoride

Abstract

The influence of gas sorption on damage nucleation of a semicrystalline polymer during coupled diffuso‐mechanical monotonic loading in tension was investigated for the first time. Alpha‐poly(vinylidene fluoride) was mechanically strained under the presence of two chemically different gases, hydrogen and carbon dioxide, at a temperature of 30°C and a pressure up to 120 bar. The cavitation damage at the microstructure scale after gas decompression was assessed from a careful SEM and TEM micrographs analysis. Compared with SEM, TEM allowed quantifying the smallest cavities (ten‐nanometer size). If decompression in hydrogen appeared to have only a slight effect on cavitation however, carbon dioxide showed a detrimental effect on damage nucleation with the exhibition of a significant population of small cavities. On the other hand, tension under gas pressure is more sensitive to hydrogen than to carbon dioxide. Once interaction with gaseous carbon dioxide takes place the plasticizing effect is in competition with damage by cavitation. POLYM. ENG. SCI., 54:2139–2146, 2014. © 2013 Society of Plastics Engineers

Kinetics of thermal degradation and lifetime study of poly(vinylidene fluoride) (PVDF) subjected to bioethanol fuel accelerated aging

“…Poly(vinylidene fluoride) (PVDF) is an engineering thermoplastic polymer widely used in the specific plastic sectors [ 7 , 8 , 9 , 10 ]. The nonpolar α -form PVDF has its use well consolidated in structural applications such as flexible pipes for oil and gas exploration [ 11 , 12 , 13 , 14 ]. PVDF can also be employed as a liner (coating) or inner layer in multilayers thermoplastic pipes or storage tanks dedicated to storage and/or transportation of biofuels, mixtures of biofuels-gasoline and sodium hydroxide solutions (except in critical conditions, i.e., temperature range from 50 to 90 °C and pH of 13.5–14), among others [ 5 , 7 , 13 , 15 , 16 , 17 , 18 , 19 , 20 ].…”

“…The nonpolar α -form PVDF has its use well consolidated in structural applications such as flexible pipes for oil and gas exploration [ 11 , 12 , 13 , 14 ]. PVDF can also be employed as a liner (coating) or inner layer in multilayers thermoplastic pipes or storage tanks dedicated to storage and/or transportation of biofuels, mixtures of biofuels-gasoline and sodium hydroxide solutions (except in critical conditions, i.e., temperature range from 50 to 90 °C and pH of 13.5–14), among others [ 5 , 7 , 13 , 15 , 16 , 17 , 18 , 19 , 20 ]. Additionally, PVDF has several other industrial uses, including valves, membrane filters, pumps and bearings, chemicals and pharmaceuticals packaging, and barrier for gaseous substances [ 7 , 8 , 19 , 21 ].…”

A Review on Applicability, Limitations, and Improvements of Polymeric Materials in High-Pressure Hydrogen Gas Atmospheres

“…[73,74] The gas permeability as a function of pressure may even plasticize the polymeric material if the penetrant gas concentration is high enough to expand the polymer matrices and subsequently increase the free volume. [75] Generally, elastomers with a greater free volume eventually allow gas diffusion through the polymer chains rather easily and the higher segmental chain mobility allows easier permeation of the gas into the polymer. [9] Further, semi-crystalline polymeric grades may reduce the crystallinity due to the rearrangement of polymer chains and subsequent possible modulation of the glassy polymer to rubber transition.…”

“…and the polymer grade (polarity, additives, etc.). [9,62,75] Therefore, the gas transportation properties are decisive factors on gas-induced material deterioration and the failure of the components at the exposure to high-pressure hydrogen gas. The following chapters review the literature on the high-pressure hydrogen gas-induced damage modes and laboratory level developments identifying the hydrogen-induced damage.…”

An in situ tensile test apparatus for polymers in high pressure hydrogen

“…16,17 Unlike the case with metals and piezoelectrics, where there is an abundance of information on the hydrogen degradation mechanisms, there is little information in the literature about the detrimental effects of hydrogen on polymers. 15,[18][19][20] Hydrogen absorption in polymers differs from that of absorption in metals 3 in that very little, if any, disassociation is expected to occur within the material. Thus, the primary damage mechanisms in polymers are expected to be mechanical a) Author to whom correspondence should be addressed.…”