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Handbook of Solvents - George Wypych - ChemTech - Ventech!

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5.2 Prediction <strong>of</strong> solubility parameter 259<br />

int<br />

hg (0) the intermolecular cohesive enthalpy per molar structural unit for a<br />

homopolymer <strong>of</strong> component B (XA=0) at Tg XA the mole fraction <strong>of</strong> component A<br />

Further, hx is obtained from equation [5.2.17], but Zg is the conformational partition<br />

function for a copolymer with XA at Tg and Z0 is the component conformational partition<br />

function for a copolymer with XA regardless <strong>of</strong> the temperature in Z. Whereas for binary<br />

random copolymers, Tg is given by: 32,33<br />

int conf<br />

int conf<br />

conf conf<br />

T = T ()( 1 h + h ( X ))/{ h () 1 + h () 1 −T<br />

( 1)( s ( 1)<br />

− s ( X ))} [5.2.20]<br />

g g g g<br />

A g g<br />

where:<br />

conf<br />

hg (1) the conformational enthalpy per molar structural unit for a homopolymer<br />

(XA=1) at Tg conf<br />

sg (1) the conformational entropy per molar structural unit for a homopolymer<br />

(XA=1) at Tg conf<br />

sg (XA) the conformational entropy per molar structural unit for a copolymer with<br />

XA at Tg Tg(1) the glass transition temperature for a homopolymer (XA=1) Thus, using equations [5.2.19] and [5.2.20], δp for binary random copolymers, including<br />

aPP, could be predicted.<br />

Table 5.2.4<br />

1-XA<br />

Tg<br />

K<br />

hg<br />

cal/mol<br />

0 270 1540<br />

hx<br />

cal/mol<br />

1600<br />

(1780)<br />

g<br />

g<br />

g<br />

h0 cal/mol δ p (cal/cm 3 ) 1/2<br />

T>T g TT g T

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