Synthesis and characterization of butadiene-1,3 and octene-1 copolymer prepared by a Ziegler-Natta catalyst based on neodymium

Abstract

Abstract:The aim of this work is to evaluate the influence of octene-1 incorporation in the polybutadiene chain on the polymerization reaction and polymer characteristics. Thus, copolymerization of butadiene-1,3 with octene-1 using a Ziegler-Natta ternary catalyst based on neodymium was performed. The weight ratios of butadiene-1,3/α-olefin 100/0, 99/1, 97/3, 95/5, 90/10, 80/20 and 70/30 were evaluated. The copolymers were characterized by size exclusion chromatography (SEC), infrared spectroscopy (FTIR) and thermogravimetric analysis (TG). The results showed that the degradation temperature (Tmax) was not affected by the addition of alpha-olefin, while the thermal behavior has undergone significant changes. The polymer microstructure was not influenced by the increasing of octene-1 content. However, a tendency to molecular mass increase was observed with the increasing of octene-1 content. It was also observed a trend in reduction of the polymerization conversion as the octene-1 content increased.

Copolymerization of 1-hexene and 1-dodecene with 1,3-butadiene by a versatate/diisobutylaluminum hydride/t-butyl chloride catalyst system

“…The isomer repeating units contents were obtained from the absorbances at 725 (cis-1,4), 910 (1,2-vinyl), and 965 cm -1 (trans-1,4), as described in our previous work [9] . The polymer molecular weight characteristics were evaluated by size exclusion chromatography (SEC), in a Waters 150-C Plus SEC, fitted with an RI detector at 30 °C, using THF as solvent at 1 mL/min flow rate.…”

“…This proves that the active site was not modified by addition of alpha-olefin. Probably the reaction mechanism to produce high content of cis-1,4 units was not modified (Figure 4a) [9,18,23,24] . This characteristic is industrially important, because polybutadiene with high content of cis-1,4 units has useful properties, such as abrasion resistance, crack resistance, resilience, hysteresis and heat buildup.…”

“…On the other hand, we did not find any articles that describe the copolymerization of butadiene with 1-hexene and 1-dodecene using a neodymium versatate/ diisobutylaluminum hydride/t-butyl chloride catalyst system. However, our group has published a work about polymerization of 1,3-butadiene and octene-1 [9] . The results showed that the polybutadiene microstructure and the degradation temperature (Tmax) were not affected by the octene-1 addition.…”

Estudo Viscosimétrico de Copolímeros à Base de 1,3-Butadieno e 1-Octeno em Tulueno e Hexano

“…Tais características conferem boas propriedades mecânicas ao polímero e, em contra partida, dificultam sua processabilidade [1][2][3][4][5] . Diante disso, uma das possíveis formas de melhorar essa processabilidade é copolimerizar o 1,3-butadieno com alfa-olefinas [6] .…”

“…Assim, ao se empregar o 1-octeno, são geradas ramificações contendo 6 átomos de carbono. Em trabalho anterior do nosso grupo [6] foi mostrado que o sistema catalítico empregado na síntese desses copolímeros, não foi capaz de polimerizar a alfa-olefina individualmente, sendo inviável, desta forma, a formação de poli (1-octeno). Diante disso, foi possível garantir que o consumo de alfa-olefina no meio reacional ocorreu somente pela inserção do 1-octeno nas cadeias de polibutadieno, fornecendo ramificações.…”