Copolymerization of Propylene with Higher α-Olefins by a Pyridylamidohafnium Catalyst: An Effective Approach to Polypropylene-Based Elastomer.

Fei Yang,Li Pan,Yuesheng Li,Zhe Ma,Bin Wang,Xiaoyan Wang

doi:10.3390/polym12010089

Fei Yang, Li Pan + Show 4 more

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https://doi.org/10.3390/polym12010089

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Abstract

In this contribution, we explored the copolymerization of propylene with higher α-olefins, including 1-octene (C8) 1-dodecene (C12), 1-hexadecene (C16) and 1-eicosene (C20), by using a dimethyl pyridylamidohafnium catalyst. A series of copolymers with varied comonomer incorporation, high molecular weight and narrow molecular weight distribution were obtained at mild conditions. The effects of the insertion of the comonomers on the microstructure, thermal and final mechanical properties were systemically studied by 13C NMR, wide-angle X-ray scattering, DSC and tensile test. Excellent mechanical performances were achieved by tuning the incorporation and chain length of the higher α-olefins. When the comonomer content reached above 12 mol.%, polypropylene-based elastomers were obtained with high ductility. A combination of excellent elastic recovery and flexibility was achieved for the P/C16 copolymers with about 20 mol.% monomer incorporation. The monomer incorporation and side chain length played a crucial role in determining the mechanical property of the outstanding polypropylene-based elastomers.

Highlights

Polyolefin represented by polyethylene (PE) and polypropylene (PP) is one of the most important kinds of thermoplastics in the market
To achieve novel PP-based elastomers with excellent performance for high value-added prospective applications, in this work, we focus on the development of elastomeric materials from the copolymerization propylene with higher α-olefins, such as C12, C16 and C20
The copolymerization reactions of propylene with higher α-olefins, including 1-octene, 1-dodecene, 1-hexadecene and 1-eicosene, were conducted under the same conditions by the hafnium catalyst in the presence of [Ph3 C] [B(C6 F5 )4 ] and Ali Bu3, which is well-known for the excellent ability to incorporate higher α-olefins [37]

Summary

Introduction

Polyolefin represented by polyethylene (PE) and polypropylene (PP) is one of the most important kinds of thermoplastics in the market It enjoys tremendous production volume and wide applications in our daily life because of their unique combination of chemical and physical properties [1,2,3,4,5]. The further prosperity of polyolefin material is motivated by thermoplastic elastomer (TPE) in high value-added applications. Because of their excellent recyclability and processability, TPE is widely used as a very attractive alternative to vulcanized rubbers in many applications [6,7]. The widely tunable properties enable the POE materials to be extensively applied in various fields ranging from elastomer products, adhesive, toughening modifier to compatibilizer

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