Synthesis and characterization of fire-retardant layers onto Polyolefin substrates

Viac o knihe

The primary objective of this work was to develop thick fire-resistant coatings capable of preventing direct flame contact. Preliminary tests indicated that thicknesses exceeding 10 µm were necessary to observe flammability effects, leading to the preparation of 40 µm thick layers. The adhesion of these thick layers is influenced by surface treatments of polyolefin substrates. Plasma exposure and the deposition of plasma polymer layers are identified as the most effective methods for enhancing adhesion, as plasma processing does not alter the intrinsic properties of materials and can be applied to a wide range, including metals. Achieving high adhesion between thick coatings and polymer substrates is challenging due to differences in chemical nature and thermal expansion coefficients, often resulting in poor adhesion. Various techniques were employed to prepare thick layers and enhance adhesion. Coatings must withstand high temperatures during flame exposure without peeling, as this would allow flames and oxygen to reach the flammable polymer substrates. A combination of deposition techniques was utilized, with plasma pre-treatment improving the adhesion of polyolefin substrates. A plasma polymer basecoat, ranging from 0.1 to 1.0 µm thick, served as an adhesion promoter. However, depositing thicker layers of 20 or 40 µm proved time-consuming, leading to the use of simple dipping or spraying methods. The effectiveness of these