?-Irradiated poly(tetrafluoroethylene) particle-filled low-density polyethylene. I. Effect of silane coupling agents on mechanical, thermal, and morphological properties

Abstract

Poly(tetrafluoroethylene) (PTFE) scraps were recovered as a filler material for low-density polyethylene (LDPE) after they were degraded by Co-60 ␥-rays under atmospheric conditions to make small-size powder. The powder PTFE, which was called secondary PTFE (2°-PTFE), was melt mixed with LDPE and then extruded to obtain 200 m films. The mechanical and thermal properties and also the morphology of the fractured surface of these 2°-PTFE-filled LDPE were studied. It was found that the addition of 2°-PTFE resulted in thermofilm property of LDPE but it slightly decreased the thermal oxidative temperature of LDPE. The tensile strength and ultimate elongation of LDPE were found to decrease with the addition of 2°-PTFE. However, when it is compared to the addition of virgin PTFE into LDPE, 2°-PTFE shows better mechanical properties due to the presence of oxy groups which are capable of interacting with the main matrix. A further improvement in mechanical properties was achieved by silane coupling agent treatment of 2°-PTFE. Silane coupling agents were found to enhance the interfacial adhesion between 2°-PTFE and LDPE. The study on the fractured surfaces by scanning electron microscope revealed this adhesion between these two polymers.

Structure and properties of polypropylene/high‐density polyethylene blends by solid equal channel angular extrusion

“…Surface morphology of PP/HDPE blend was observed with a JSM‐5910 scanning electron microscope (SEM). Before observation, samples were treated with etching agent (a solution of KMnO 4 , 1.3 wt %; H 2 SO 4 , 65.8 wt %; H 3 PO 4 , 32.9 wt %) for 24 h, then washed out the etching agent thoroughly with H 2 O 2 and H 2 O, dried at room temperature and sputter‐coated with gold. Impact fracture surface of PP/HDPE blends was directly observed by SEM.…”

Radiation grafting of vinyl monomers onto poly(tetrafluoroethylene) powder produced by ? irradiation and properties of grafted poly(tetrafluoroethylene) filled low density polyethylene

“…The other details of the 2°-PTFE blended with LDPE were discussed in our previous study. 21 The LDPE was supplied by the Turkish Petrochemical Industry G03-5-PETKIM. The melt flow index and density of the polymer were 0.3 g/10 min and 0.921 g/mL, respectively.…”

“…The details of the film preparation were discussed in our previous study. 21 SEM analysis was made on both monomer grafted 2°-PTFE powder samples and tensile fractured surfaces of the monomer grafted 2°-PTFE powder filled LDPE film samples at various magnifications after gold plating by using a Jeol JSM-6400 SE microscope.…”

“…Some of these blend and composite applications of PTFE with polyacetal, polyethylene (PE), poly(ether ether ketone), and polypropylene were summarized in our previous study. 21 Ionizing or high energy radiation was also studied for radiation grafting of monomers onto PTFE in particular by either direct or preirradiation grafting techniques. The details of radiation induced grafting of vinyl monomers into PTFE films are summarized in the literature.…”

Preparation and characterization of poly(ethylene terephthalate) powder-filled high-density polyethylene in the presence of silane coupling agents

“…23,24 Both heat treatment and grinding processes in amorphous PET inevitably increased thermal decomposition and further oxidation. Zimmerman 25 showed that an extensive autocatalytic reaction by hydrolytic cleavage of polyester chains resulted in carboxyl groups under isothermal heating. Similar results were reported earlier by Buxbaum,26 and the degradation mechanism was also reviewed by Jabarin.…”