High density polyethylene microhardness

Figure 1.2. Typical microhardness values of polymers compared with data for metals. LDPE, low-density polyethylene HDPE, high-density polyethylene PA, polyamides POM, polyoxymethylene CEPE, chain-extended polyethylene CF-composite, carbon-fibre composite PS, polystyrene PEN, poly(ethylene naphthalene-2,6-dicarboxylate. (From Balta Calleja Fakirov, 1997.)...

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. 

Figure 19 Plot of microhardness as a function of degree of crystallinity (from density) for high density polyethylene, low density polyethylene, and linear low density polyethylene. (From Ref 5.)...

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See also in sourсe #XX -- [ ]

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