Preparation and Physical Properties of Novel Fluorin Surfactants and Their Grafting Copolymers with LLDPE
The series of nonionic fluorin surfactants, I, II, III, IV, V and their acrylates, A-I, A-II, A-III, A-IV and A-V, were synthesized by using poly(ethylene oxide)(PEG)(600,1000,1500,2000,4600) as the main starting materials. Their chemical structures were characterized by means of FTIR and 1H NMR. The surface activity and surface tension (γ) of I, II, III, IV and V were evaluated by drop weight method. It was found that their surface tension increased with the length of PEG in the molecular chains. A-I, A-II, A-III, A-IV and A-V were adopted as the grafting monomers of LLDPE, and grafting reaction was carried out by using melt reactive extrusion procedure. The graft degrees of LLDPE were determined by FTIR. Five grafted LLDPE samples with grafting degrees of 0.72% (A-I), 0.72% (A-II), 0.68%(A-III), 0.63%(A-IV) and 0.57% (A-V) were prepared. Their surface properties were characterized by measuring contact angle and oxygen content. Thermal properties of grafted LLDPE samples were studied by using DSC. It was found that their isothermal crystal behavior could be described with the Avrami equation. The crystallization rates of grafted LLDPE were faster than that of the plain LLDPE at a given crystallization temperature.