Abstract
Hyper-branched 4A zeolite (HB-4A zeolite) was prepared by condensation reaction between 4A zeolite and the monomer we prepared. It was then characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). This HB-4A zeolite was then used in the preparation of natural rubber (NR)/HB-4A zeolite composite. Different types of NR/HB-4A zeolite composites were prepared with different amounts of HB-4A zeolite and compared with the composites directly incorporated with 4A zeolite. The cure characteristics of different 4A zeolite filled NR composites were studied. Then, the tensile and thermal properties were compared. Results revealed that the mechanical properties of NR/HB-4A zeolite, especially elongation at break, showed a remarkable enhancement compared with that of NR/4A zeolite and NR systems. SEM studies showed that hyper-branching modification might increase the compatibility between 4A zeolite and NR matrix. A reinforcing mechanism was proposed, assuming that the ‘anchor’ effect caused by the hyper-branched polymer may reduce the amount and size of voids and increase the length of the crack spread path during tensile drawing.