Study On Preparation, Structures And Properties Of HVPBR/OMMT Nanocomposite

HVPBR/organic montmorillonite nanocomposites (HVPBR/OMMT NCs) were prepared by in-situ polymerization of butadiene with MoCl3(OC8H16)2 and Al((OPhCH3)(i-Bu)2) catalyzed system in existence of OMMT. The effect of the type, amount and addition method of OMMT on the catalysis activity, structures and properties of the prepared composites were studied. The structure and properties of composites were characterized using X-Ray Diffraction (XRD), Fourier transform infrared analysis (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), gel permeation chromatography (GPC), thermogravimetric analysis (TG), and dynamic mechanical analysis (DMA). The dynamic rheology property of composites were studied with RPA2000. The mechanical properties of HVPBR/OMMT NCs were also tested.The result revealed that the intercalated HVPBR/OMMT NCs could be prepared by the in-situ intercalation polymerization of butadiene with Mo-Al catalyzed system in existence of OMMT in the solution of hydrogasoline. The effect of amount of OMMT (OMMT/Bd <6%(wt)) on catalysis activity and intrinsic viscosity was very small. A uniform dispersion of OMMT layers was achieved in the polymeric matrix. The prepared NCs were of mainly intercalated structure, as revealed by XRD, while some intercalated OMMT layers were found in TEM. The result of SEM shows that the OMMT NCs have a certain aggregates. The addition of OMMT improved the stereoregularity of HVPBR: the content of 1,2 units increased, while the content of trans-1,4 units decreased after the introduction of OMMT. Moreover, the molecular weight increased and the molecular weight distributions became narrower by the addition of OMMT. The properties of the NCs were influenced greatly by the addition of OMMT. The thermal stabilities of NCs increased dramatically compared with pure HVPBR. Both the storage modulus and Tg increased greatly, and tan was decreased. The dynamic rheology property of composites were studied with RPA2000. In the process of frequency sweep and strain sweep, G′and tan were both higher than that of HVPBR. For temperature sweep model, G′, tan and Eηwere higher than that of HVPBR. The value of Mooney viscosity of composites was decreased and the vulcanizing time was shorten. The mechanical properties of vulcanizate without carbon black, such as tensile strength, tear strength and elongation at break were improved significantly in comparison with those of pure HVPBR. The mechanical properties of vulcanizate with carbon black, such as tensile strength, permanent deformation, density, Shore hardness and aging resistance were improved significantly in comparison with those of pure HVPBR, but tear strength, Elongation at break and heat compression were decreased.