Effect of Silane Coupling Agent on Physical Properties of Polypropylene Membrane Reinforced by Native Superfine down Powder

In order to improve the compatibility between native superfine down powder (NSDP) and polypropylene (PP), NSPD was surface-modified by grafting with a silane coupling agent. After modification of NSDP, Fourier-Transform infrared spectrometry was used to investigate the chemical reaction between NSDP and silane coupling agent, and the spectroscopy indicated that silane coupling agent was successfully grafted onto the particle surface. Modified and unmodified NSDP was used to reinforce PP membrane by hot-press method, and the morphology, thermal properties, melt mass-flow rate and mechanical properties of PP/NSDP hybrid membrane was investigated. The melt mass-flow rate, tensile stress, and break elongation of the hybrid membranes initially increased and then decreased with the increase of silane coupling agent concentration, which significantly correlated with the silane coupling agent amount that adhered on the particle surface. Up to 3% silane coupling agent concentration was sufficient to cover the NSDP surface and improve the compatibility between PP and NSDP. With continuously increasing of silane coupling agent concentration, the melt mass-flow rate and mechanical properties decreased, which ascribed to the decreasing bonding strength of entanglement network between long-chain hydrocarbon segments on NSDP surface and PP matrix. PP/NSDP hybrid membrane with excellent thermal and mechanical properties can be obtained by controlling the silane coupling agent concentration.