Evaluation of Octyltetramethyldisiloxane‐Containing Ethylene Copolymers as Composite Lubricant for High‐Density Polyethylene

Abstract

A series of octyltetramethyldisiloxane‐containing ethylene copolymers, poly(ethylene‐co‐OO7) (abbreviated as E‐co‐OO7), are prepared from vanadium catalyzed copolymerization of ethylene with 1‐oct(7‐en)yl‐3‐octyl‐1,1,3,3‐tetramethyldisiloxane (or OO7) macromonomer. The copolymers containing different silicone contents are employed as composite lubricants for high‐density polyethylene (HDPE). The influences of the silicone content in the copolymer and that of the added copolymer amount in the blend on the bulk and surface properties of the blends are systematically investigated. The results show that E‐co‐OO7 exhibits superior overall performance in comparison with conventional lubricants silicone masterbatch and polyethylene wax. Compared to HDPE control, 10 wt% E‐co‐OO7 addition increases the melt flow rates by 49%, increases the elongation at break from 740 to 860%, increases the water‐contact angle from 90° up to 108°, lowers the coefficient of friction from 0.072 to 0.049, lowers the specific wear rate from 11 × 10−3 to 5.6 × 10−3 mm3 Nm−1. The impact strength and high temperature thermal stability are also slightly improved. The measured Si/C atomic ratios demonstrate the sufficient silicone enrichment on surface of the blends. E‐co‐OO7 with 23.5 SiOSi per 1000 C gives the best internal lubrication, and E‐co‐OO7 with 29.7 SiOSi per 1000 C gives the best external lubrication.

Facile synthesis and applications of polypropylene/polydimethylsiloxane graft copolymer

“…Beyond the application of PP ‐g‐ PDMS as a compatilizer for PP/PDMS blend, it may also function as a processing aid for high‐viscosity PP that make an injected or molded product both possible and profitable . Jin et al illustrated that siloxane‐containing ethylene copolymer can serve as an effective multifunctional/composite lubricant for high‐density polyethylene and exhibits overall superior performance in comparison with conventional internal (PE wax) or external (silicone masterbatch) lubricants, since it strikes a good balance between soluble flow‐enhancing lubrication and insoluble surface‐modifying lubrication. PP ‐g‐ PDMS, a novel silicone‐containing PP‐based copolymer and moderately soluble in PP matrix, is likely to reduce the friction between PP macromolecular chains when they sliding against each other.…”

“…Beyond the application of PP-g-PDMS as a compatilizer for PP/PDMS blend, it may also function as a processing aid for highviscosity PP that make an injected or molded product both possible and profitable. 14,17 Jin et al 18 The complex viscosity curves of pure PP and its blend with PP-g-PDMS were shown in Figure 11. The results show that dynamic complex viscosity of PP/PP-g-PDMS blend decreased dramatically compared with pure PP in whole frequency range (0.1-100 rad/s).…”

Recent Advances in Nickel Catalysts with Industrial Exploitability for Copolymerization of Ethylene with Polar Monomers

“…The supported phosphinephenolate Ni catalyst 10a-Na-MgO was used for the synthesis of ethylene and n-butyl Vinyltrimethoxysilane (VTMOS) is easier to copolymerize with ethylene than other fundamental polar monomers because it has lower toxicity for the catalyst. The functional polyethylenes containing silicon-oxygen bonds can serve as versatile processing additives [89,90]. Homogeneous imine-bridged bisphosphine-monoxide Ni catalysts 6b and 6d, as well as the heterogeneous phosphine-phenolate Ni catalyst 10a-Na-MgO, have been reported for synthesizing ethylene and VTMOS copolymers at 80 °C (Table 3, Entries 1-3) [62,70].…”

Fabrication of cellulose nanocrystals (CNCs) in choline chloride-citric acid (ChCl-CA) solvent to lodge antimicrobial activity

“…Recently, nanosized and high crystalline cellulose with high rigidity, tensile stiffness, and shear force has attracted much attention due to its intrinsic properties (Habibi 2014;Wang et al 2018). Thus, cellulose nanocrystals (CNCs) can be used as a reinforcing material to improve surface and antifouling properties of polymers (Jin et al 2016;Rodrigues et al 2017;Bai et al 2019). In addition, CNCs possess hydroxyl groups and can be modified by oxidation, esterification, etherification, and grafting copolymerization (Liu et al 2017a).…”