The present work evaluates the partial oxypropylation of dried bacterial cellulose (BC) performed by grafting propylene oxide with potassium hydroxide as the catalyst. Samples were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. Partial transformation of BC was observed, with cellulose fibers being covered by the thermoplastic phase, leading to a new biphasic mono-component composite material. This synthesis can be considered a green chemical process, since it does not require the use of solvents nor the application of any processing operation, given the fact that the final product is ready for further exploitation as it is removed from the reactor. The obtained material can be used in various applications in the polymer field, i.e. composites, reinforced rigid polyurethane foams, and others.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Univ Fed Uberlandia, Inst Quim, BR-38400902 Uberlandia, MG, BrazilUNESP, Inst Quim, Lab Mat Foton, Araraquara, SP, BrazilUNESP, Inst Quim, Lab Mat Foton, Araraquara, SP, Brazil