Özet. Bu çalışmada maleik anhidrit-stiren kopolimerinin ısısal kararlığını artırmak için, maleik anhidrit-stiren kopolimeri; n-propil alkol, n-butil alkol ve amonyak ile tepkimeye sokularak onun  monoester ve karboksilat tuzu türevleri elde edildi. Karakterizasyon için Fourier dönüşümlü infrared spektroskopisi (FTIR)  ve ısısal analiz için Termogravimetrik Analiz (TGA)  kullanıldı. Çalışma sonucunda TGA eğrilerine göre maleik anhidrit-stiren kopolimerinin ester türevleri normal kopolimere göre ısıya karşı daha az kararlılık göstermesine karşın ester türevlerinden elde edilen karboksilat türevlerinin hem normal kopolimere göre ve hemde onun ester türevine göre ısıya karşı daha kararlı olduğu görülmüştür. Abstract. In this study, to increase thermal stability of maleic anhydride styrene copolymers; monoesters and carboxylate salt derivatives of maleic anhydride styrene were obtained by reaction of maleic anhydride styrene copolymer with n-propyl alcohol, n-butyl alcohol and ammonia. Fourier transform infrared spectroscopy (FTIR) was used for characterization and Thermogravimetric Analysis (TGA) was used for thermal analysis. As an result of this study, when TGA curves were analyzed, though ester derivatives indicated less stability  against temperature, thermal stability of carboxylate derivatives obtained from ester derivatives were more stable compared to normal copolymer and its ester derivative. In this study, to increase thermal stability of maleic anhydride styrene copolymers; monoesters and carboxylate salt derivatives of maleic anhydride styrene were obtained by reaction of maleic anhydride styrene copolymer with n-propyl alcohol, n-butyl alcohol and ammonia. Fourier transform infrared spectroscopy (FTIR) was used for characterization and Thermogravimetric Analysis (TGA) was used for thermal analysis. As an result of this study, when TGA curves were analyzed, though ester derivatives indicated less stability against temperature, thermal stability of carboxylate derivatives obtained from ester derivatives were more stable compared to normal copolymer and its ester derivative.