STRUCTURE PROPERTY RELATIONSHIP (QSPR) STUDY OF GLASS TRANSITlON TEMPERATURES OF POL Y(ACRYLIC ACID) DERIVATES. Quantitative Structure-Property Relationship (QSPR) stlJdyof glass transition temperatures of poly(acrylic acid) derivates has been conducted. The study was done by using molecularmodelling of polymers assumed in trimer compound, in their isotactic form. Calculation was performed by semiempirical PM3method. The relationship analysis between Tg and physicochemical properties of polymers was done by multilinear regressionanalysis, with T IBM as dependent variable and 10 independent variables such as atomic net charges of carbon as head and tailof the polymer ~hain (qC1 and qCj, dipole moment (~), polarizability «1), refractivity index (RD), log P, volume (V vdW) ;lndsurface area of van der Waals (AydW)' solubility in water (log Sw) and parachor index. The relationship between T" and thedescriptors which performed by statistical calculation is: (T IBM) = 8.764 + 0.315(qC.) + 0.513«1) -0.253(~) -0.0515(IR.D)-0.876(Log P) -0.0411 (V vdw) + 0.02215(AYdw) + 0.005242(Parachor) -1.0 18(Log Sw)' with n =29; r = 0.904; r2 = 0.817;SD = 0.441; F calc = 9.395; F table = 2.423 dan F calc/F table = 3.878; PRESS = 3.7196.Key words: QSPR, glass transition temperature, poly(acrylic acid), atomic net charge. PORCO Iswanto., Iqmal Tahir daD Hamo Dwi Pranowo2; 1 Jurusan Kimia, FMIP A -Unsoed, Purwokerto; 2 AIC, Jurusan Kimia -FMIP A UGM, Jl. GrafIka 2, Yogyakarta