High-density polyethylene chemical structure

Other applications for THV are flexible liners (drop-in liners or bag liners), used in chemical process industries and other industries, and blow-molded containers, where it enhances the resistance to permeation when combined with a less expensive plastic (e.g., high-density polyethylene-HDPE), which provides the structural integrity.61 Optical clarity, excellent weatherability, and flexibility make THV suitable as a protection of solar cell surface in solar modules.63... 

The microhardness of LDPE fractions and of high-density polyethylene (HOPE) samples has been studied as a function of molecular weight in the range of about 2 X 10 up to 4 X 10 (Baltd Calleja et al, 1997). Details of the lamellar structure were determined by TEM. The observed decrease of microhardness with increasing molecular weight is mainly due to the increase in thickness of the interlamellar layers (i.e. a decrease of crystallinity). After chemical treatment with chlorosul-phonic acid and with OSO4, samples show a drastic increase in microhardness. 

Long-term oxidative degradation of an ion-beam irradiated polymer was studied. Silicon oxide thin layers were deposited on the surfaces of high density polyethylene (HDPE) to suppress the oxygen permeation. HDPE samples irradiated with a C6+ ion-beam were stored up to 12 months after the irradiation and the evolution of the chemical structure was followed by micro-Fourier transform infrared (micro-FT-IR) spectroscopy. Silicon oxide layers were found effective to suppress the long-term oxidative degradation of the ion-irradiated polymer. 

Thus this simple model accurately described optical aspects of the molecular reorientation observed in deformation bands, in PET polypropylene(PP) and high density polyethylene (PE), in terms which are completely independent of the chemical structure of the chains, and independent of the fact that one of the materials, PET, is of low crystallinity tested below its glass-transition Tg, whereas the other two are appreciably crystalline, tested above their Tg. The success of this simple phenomenological description of the reorientation should not be considered to imply that the molecular deformation processes are themselves simple. Taken at face value, the model suggests that the microscopic structural units... 

The relationship between chemical structures and their physical performance is one of the central topics of polymer physics. lUPAC has recommended a whole set of names to describe the detailed chemical structures of polymer chains and their derivatives. However, in our daily communication, people prefer to use the popular names of polymers reflecting their characteristic physical performances, such as high-density polyethylene (HOPE), foamed polystyrene, thermoplastic elastomers, liquid crystal polymers, conductive polymers, and polyelectrolyte. Such terminology allows us to comprehend quickly the basic characteristics of chemical structures responsible for their specific physical properties. 

The study of the morphological characteristics of polymeric membranes is of great interest in the area of membrane science (Resting, 1971). It has been known that one of the keys to better membrane performance lies in the structure of the membrane itself. In turn the morphology of a particular membrane depends upon its processing conditions and the physical and chemical properties of the polymer system under consideration. Membranes from polypropylene (Porter, 1982), high-density polyethylene (Porter, 1982), polyvinylidene fluoride (Hiatt etal., 1984 Hiatt, 1985)... 

Elnorinated PEPE molecnles are very lubricious by themselves, which may be attributed to their linear and smooth molecular profile, as evidenced by the molecular-scale friction work carried out by Tabor and coworkers on poly(tetrafluoroethy lene) (PTFE), high-density polyethylene (FIDPE), and several other polymers [69]. It may be noted that PEPE and PTEE molecules are very similar in the sense that both have common CE2 chemical groups in their backbone and both have linear molecular structure. 

High density polyethylene (HDPE) has balanced mechanical properties with good chemical resistance. It has better barrier properties against gases and vapors. It is also harder and stiffen The structure of HDPE is described as semi-crystalline [31]. LDPE is soft and flexible [32,33]. High density polyethylene has been identified as a primary material for solid waste minimization and recycling in blow molding. 

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