The influence of Ni/Nd‐based Ziegler–Natta catalyst on microstructure configurations and properties of butadiene rubber

Abstract

Neodymium (Nd)-based Ziegler-Natta catalyst has been well known for preparing polybutadiene rubber (BR) containing high, about 98%, cis21,4 configuration with extremely low gel content providing superior resistance to low-temperature fatigue and abrasion. However, its cost is more expensive than a conventional nickel (Ni)-based catalyst. The Nd-BR has poor processability with high cold flow due to its high linearity and molecular weight. To compare with a traditional process, the BR produced by Ni-based catalyst has higher level of branching resulting in the better processability, but it contains medium amount of gel. To balance the catalyst cost and the BR properties, this article reported the influence of a solution containing Ni-and Nd-based Ziegler-Natta catalyst (Ni/Nd) using diethyl aluminum chloride and triethyl aluminum as co-catalysts on 1,3-butadiene (BD) conversion and physical properties of the elastomeric materials based on obtained rubber (Ni/Nd-BR). In the presence of toluene, the increase in the Ni/Nd molar ratio from 0.0/1.0 to 0.4/0.6 yielded Ni/Nd-BR containing cis21,4 units of 95%-96% with significantly decreasing both levels of vinyl21,2 and trans21,4 configurations from 0.26% to 0.13% and 4.44% to 3.07%, respectively. When cyclohexane was applied as the reaction media, 100% BD conversion was achieved and the Ni/Nd-BR had very low content of vinyl21,2 unit (0.07%). The mechanical properties in terms of tensile properties and abrasion resistance of the elastomer based on Ni/Nd-BR having high cis-1,4 and relatively higher trans21,4 configurations were superior to elastomers based on commercial BRs produced by using Niand Nd-based catalyst systems.

The role of iron(III) oxide in chloroprene and butadiene rubber blends’ cross-linking, structure, thermal and mechanical characteristics

“…These results are not unexpected, as standard CR vulcanizates need protection by antioxidants against thermal aging and by anti-ozonants to improve ozone resistance. The use of these ingredients also improves flexfatigue resistance [1].…”

“…According to oxygen index (OI), the materials were divided into [27]: flammable materials (OI ≤ 21%), flame-retardant materials (OI = 21-28%), and non-flammable materials (OI ≥ 28%). Notably, cured chloroprene rubber is inherently flame retardant [1]. The OI of conventionally cross-linked CR (e.g., with zinc oxide and magnesium oxide) is 26% [28].…”

“…However, the flame resistance of the CR vulcanizates is not sufficient and for many applications further improvement is needed. To achieve a higher flammability of CR vulcanizates, aluminum trihydrate, zinc borate or antimony trioxide is used [1]. In our study, we have decided to investigate the flammability of the CR/BR/Fe 2 O 3 products.…”

“…The vulcanizates of BR have superior tensile strength, low hysteresis loss, good wear resistance, low rolling resistance, and for these reasons about 70% of the total production of BR is used in the tire industry. Butadiene rubber is commonly blended with other rubbers instead of being used alone [1][2][3][4][5][6][7].…”

Butadiene Rubber: Synthesis, Microstructure, and Role of Catalysts

“…Chatarsa et al reported that Ndbased ZN catalyst with a combination of transition metals (i.e., Ni-[Ni/Nd]) using DEAC and TEAL as co-catalysts influenced the polymerization of 1,3-BD. 73 The results revealed that both the vinyl-1,2 and trans-1,4 content in high cis-1,4 polybutadiene (95-96%) is significantly reduced with an increase in the Ni/Nd molar ratio.…”