Synergistic effects of zwitterionic segments and a silane coupling agent on zwitterionic shape memory polyurethanes

Abstract

Recently, zwitterionic shape memory polyurethanes (ZSMPUs) have found many promising applications in smart biomedical field. This paper provides a novel strategy to improve shape memory properties of ZSMPUs by using a silane coupling agent, namely 3-glycidyloxypropyl-trimethoxysilane (KH560). The synergistic effects of zwitterionic segments and silane coupling agents on the structure, morphology, thermal properties, mechanical properties, and shape memory properties were carefully investigated.The results demonstrate that the incorporation of KH560 does not influence the original molecular structure and morphology of ZSMPUs, and the KH560-modified ZSMPUs form a hard-soft phase separation structure. Also, the KH560 modification promotes the entanglement of hard segments, and thus provides better mechanical properties to ZSMPUs-KH560. Moreover, the silane coupling agent can provide lubrication to influence the aggregation of soft segments while the zwitterionic segments promote the formation of crystal seeds. Therefore, a good semi-crystalline soft phase endows the ZSMPUs-KH560 with a decent shape fixity (e.g. above 94%), and the entangled hard segments greatly enhance the shape recovery of ZSMPUs (e.g. above 90%).

Zwitterionic Poly(aryl ether ketone) with Water-Actuated, Reshaping-Reconfiguration Ability and Triple Shape Memory Effect

“…Zwitterionic polymers (ZPs) both possess anion groups and cation groups or blended zwitterionic terminal groups in molecular chains, and the quantities of positive charges are same as the number of negative charges in the polymer system. − Because of the existence of anion and cation groups, ZPs exhibit excellent thermal stability, chemical resistance, biocompatibility, and antifouling performances, − which have been widely used in fields of antifouling layers, biomedical materials, and delivery carriers. − Besides, the intellectualization of ZPs has attracted the researchers’ attention. Because of the excellent water absorption capacity, the integration of ZPs into SMP matrix might largely improve the hydrophilicity, imparting diverse functionalities, such as water actuation, reconfiguration ability, and multiple stimuli responses. − …”

Surface grafting stearic acid to the coupling agent on attapulgite: A reinforced filler in castor oil‐based polyurethane coating

“…The presence of epoxy groups in KH‐560 was confirmed by peaks at 1256 cm −1 and 912 cm −1. 49 After the ac‐AT was modified with KH‐560, the FT‐IR spectrum of the MAT 1 still exhibited the characteristic peaks that were presented by ac‐AT (Figure 1a,b,c). But differently, three peaks appeared at 2969 cm −1 , 2939 cm −1 , and 2873 cm −1 (Figure 1a,c), corresponding to the asymmetrical and symmetrical stretching vibrations of C‐H bonds.…”

Surface engineering of a pervaporation desulfurization membrane with crack structures by the self‐condensation of silane coupling agent

“…In Figure 3, the NH stretching vibration peak at 3325 cm À1 , the NH deformation vibration peak at 1528 cm À1 and the C═O vibration absorption peak at 1731 cm À1 correspond to the characteristic peaks of the carbamate group in PU. 27 KH570 has three functional groups of Si O Si, C═O and C═C at 1100 À1 -1030 cm À1 , 1720 and 1638 cm À1 , respectively, 28 the three characteristic peaks coincides with the peak of PU. Compared with PU, the infrared characteristic peak of KH570-PU does not disappear or weaken, and carbamate in PU can form hydrogen bond with silanol.…”