The density and associated percent crystallinity for two poly(ethylene terephthalate) materials are as follows: rho (g/cm3 ) crystallinity (%) 1.408 74.3 1.343 31.2 (a) compute the densities of totally crystalline and totally amorphous poly(ethylene terephthalate). (b) determine the percent crystallinity of a specimen having a density of 1.382 g/cm3 .

A)

B) 66.6%

Explanation:

A) expression for crystallanity is given as

     ........1

where, \rho_c = density of crystalline, \rho_a = density of amorphous material,

 = density of specimen

C = 0.743 [given]

 ........2

SUBSTITUTE value of second specimen in 1 equation we get

.......3

ON COMPARING 2 AND 3rd equation we get

b)

substitute value to ger crystallanity

C = 66.6 %      

answer:

31

explanation:

answer:

explain:

we don't have any choices.