CANCELLED: Application of Neodymium Isoprene Rubber in Tread of Truck Tire

The microstructure and sequence distribution of isoprene rubber obtained with homogeneous neodymium-based catalyst were determined by means of ¹H-NMR and ¹³C-NMR spectroscopy. The results demonstrate that the content of cis-1,4 configuration in neodymium isoprene rubber (Nd-IR) are above 98% and trans-1,4 configuration are absent. All monomer units of Nd-IR exist in “head-tail" structure, which are the same as the microstructure of nature rubber (NR). The molecular weight and its distribution of Nd-IR were measured by a gel permeation chromatography (GPC). The GPC trace is unimodal and the polydispersity index is 2.67, which is narrower than that of NR. The mechanical properties of Nd-IR and NR were characterized according to ASTM D3403. The results show that no significant differences between the properties of Nd-IR and that of NR indicate that Nd-IR have excellent properties. It can be attributed primarily to high cis-1,4 content in Nd-IR macromolecular chain and relatively narrow molecular weight distribution. Finally, Nd-IR was used to produce tread of whole-steel heavy-load meridian tires, which substituted for 60% of NR. Compared to tires with tread made by 100% NR, the moulding, machining and usage performance of tires with tread made by 60% Nd-IR are basically not affected. Especially to deserve to be mentioned, the endurance of tires with 60% Nd-IR is 122.3h, which is nearly twice of that of tires with 100% NR.