Carbonyl hydrosilylation reaction was developed to prepare either polybutylene terephthalate (PBT)/polysiloxane (PMHS) crosslinking network or compatibilized polymer blends. It is focused on the addition reaction of hydrogenosilane groups (SiH) from polysiloxane onto carbonyl groups from PBT catalyzed by trirutheniumdodecacarbonylRu3(CO)12 . An approach on PBT model compounds was carried out to investigate the potentiality and efficiency of carbonyl hydrosilylation reaction with 1H NMR. During kinetic study, at lower temperature100oC, the hydrosilylation reaction can reach 3 mol% after 4 hours. Some side reaction can reach up to 23 mol%, especially at high temperature such 180oC Hydrosilylation reaction was extented to PBT modification. The formation of PBT network was investigated by rheology and SEM, the gel fraction was measured in a mixed solvent HFIP and chloroform. The impact of both shearing and hydrosilylatio reaction on the final morphology was deeply studied. In addition, the reaction is also applied to Polyamide12 (PA12). Since the process temperature of PA12 is lower than PBT, the side reactions are inhibited, we get PA12/PDMS blend with better dispersion and stability. References [1]P. Cassagnau, F. Fenouillot, Polymer 45 (2004) 8019-8030. [2]U. Sundararaj, C.W. Macosko, Macromolecules 28 (1995) 2647-2657. [3]K. Prakashan, A.K. Gupta, S.N. Maiti, J. Appl. Polym. Sci. 105 (2007) 2858-2867 [4]J. Bonnet, V. Bounor-Legaré, P. Alcouffe, P. Cassagnau Materials Chemistry and Physics 136 (2012) 954-962