Modern societies rely in a continuous and stable supply of energy to support their economies, industrial capacity, and demographic growth. The overall demand of energy worldwide has been uninterruptedly increasing during the last 50 decades, resulting in higher consumption of natural resources, production of greenhouse gases, and deterioration of the environment. Consequently, several countries have agreed to transit towards sustainable development models and to reduce their emission of pollutants. The use and improvement of thermo-acoustic insulation systems have proved to increase comfort and to lower power consumption for air-conditioning purposes in buildings and transportation systems. Notwithstanding, most thermo-acoustic insulators are made up of neither renewable nor degradable components which pose potential threats to the environment and human health. The current research project aims to develop sustainable and efficient thermo-acoustic insulators made of polyurethane foams (PUF) filled with seedpods fibres of milkweed (MWF), which is a native Canadian fiber with remarkable intrinsic thermal insulation properties. The project was carried on in two phases. The first phase focussed on the formulation of PUFs, while the second one dealt with the elaboration, characterization, and optimization of PUFs-MWF composites Polyurethane foams were synthesized using different proportions of bio-degradable polyether polyol, water, methylene diphenyl diisocyanate and catalysts. Density, thermal conductivity, coefficient of acoustic absorption, compression resistance, cell size and distribution were thoroughly measured for each sample of pure PUFs. Subsequently, the optimal formulation of PUF was selected to fabricate PUF-MWF composites with different PUF/MWF weight ratios, and the morphology and thermo-acoustic properties of these composites were evaluated and compared with the properties of the pure PUF.