High shape‐memory effect of hindered phenol/nitrile–butadiene rubber composites by forming hydrogen bonding

Abstract

To widen the type and scope of use of shape memory polymers (SMPs), we added hindered phenol (AO-80) to nitrilebutadiene rubber (NBR) to gain a group of AO-80/NBR rubber composites. The glass transition temperature (T g ), structure, mechanical properties, and shape memory properties of the AO-80/NBR rubber composites were characterized. It was concluded that the dispersion of AO-80 in the NBR matrix was homogeneous and intra-molecular hydrogen bonds were formed between the hydroxyl groups ( OH) of AO-80 and the cyano groups ( CN) of NBR molecular chain. The dosage of AO-80 added could be changed to tune the T g . AO-80/ NBR rubber composites revealed outstanding shape fixity and shape recovery. The method for tuning the T g of AO-80/NBR rubber composites will provide an idea for the fabrication and design of new SMPs.

Shape Memory Materials from Rubbers

“…This effect can be exhibited by both virgin polymers and their composites [ 18 , 19 , 20 ]. Elastomers, such as nitrile butadiene rubber, natural rubber, epoxidized natural rubber, silicon rubber, and polyurethane, etc., are widely studied because of their shape memory effect [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. Various fillers, such as silica, graphene oxide, carbon nanotubes, and nano clay, etc., improve the shape recovery, mechanical strength, and elastic modulus, as well as reduce recovery time.…”

Effect of triethylene glycol bis(3‐tert‐butyl‐4‐hydroxy‐5‐methylphenyl)propionate on structure and mechanical properties of nitrile butadiene rubber/clay nanocomposites

“…Hindered phenol is a kind of polar organic molecule with two phenolic hydroxyl groups at its chemical structure, which can form hydrogen bonds with nitrile groups 26 . By introducing hindered phenol in the NBR matrix to construct hydrogen bonds between phenolic hydroxyl and nitrile group, the damping property was significantly enhanced 27–29 . Liang et al 18 used a hindered phenol, (tetrakis[methylene‐3‐(3‐5‐ditert‐butyl‐4‐hydroxyphenyl) propionyloxy]methane (AO‐60)), as an interfacial modifier to prepare NBR/clay composite, where both mechanical and damping properties were improved.…”

“…26 By introducing hindered phenol in the NBR matrix to construct hydrogen bonds between phenolic hydroxyl and nitrile group, the damping property was significantly enhanced. [27][28][29] Liang et al 18 used a hindered phenol, (tetrakis[methylene-3-(3-5-ditert-butyl-4-hydroxyphenyl) propionyloxy]methane (AO-60)), as an interfacial modifier to prepare NBR/clay composite, where both mechanical and damping properties were improved. However, the clay filler was simply mechanically blended into the NBR matrix and the clay layers were dispersed in the NBR matrix at a micro-scale rather than the nano-scale, so the mechanical properties were not as good as expected.…”

Polyurethanes Based on Polylactic Acid for 3D Printing and Shape-Memory Applications

“…The properties of PU can be tailored by changing the content and type of its hard segment (HS) and soft segment (SS). Therefore, the T g of PU can be tailored by modulating its SS and HS. − Several PU-SMPs have been developed considering this property, and the market demand for these materials, especially for products suitable for the human body, has steadily increased. ,,− The in situ formation of cross-linked PU from polyols and multifunctional isocyanates has been widely investigated in efforts to enhance the toughness of PLA , and modified PLAs have been successfully employed to synthesize PLA-TPUs with excellent toughness. However, T g of these materials is unsuitable for use in the human body. , Therefore, the development of methods to design PLA-TPUs with good recyclability, biocompatibility, and biodegradability, recovery temperatures near 37 °C, and customizability for different needs using 3D printing is of great practical significance for medical materials.…”