Study Of Shape Memory Effect Of Hindered Phenol/Rubber Composites

At present, shape memory polymer is one of the hotspot in research of shape memory materials. The polarity rubber itself had shape memory effect, but its shape memory transition temperature (Ttrans), which was also the glass transition temperature (Tg) was always below room temperature, This restricted the use of the rubber matrix as shape memory material.To make the shape memory properties of rubber more practical application value, it was necessary to improve the Tg of rubber. The hindered/rubber composites were prepared at high temperature by the method of vulcanization. Carboxylated nitrile rubber (XNBR)、 polyacrylate rubber (ACM) and Nitrile-Butadiene Rubber (NBR)were used as the matrix. Microstructure of composites were the characterization of X-ray Diffraction (XRD)、Scanning Electron Microscope (SEM) and Fourier Infrared (FT-IR); Thermal properties of composites was analyzed by Differential Scanning Calorimetry (DSC); dynamic mechanical properties was tested with dynamic mechanical analyzer (DMA); High resolution camera was used to recorded shape memory recovery of comoposites. Under were the main conclusions.(1)AO-80/XNBR composites were successfully prepared, the study showed that, AO-80and XNBR had good compatibility, there was no AO-80gather phase found in XNBR matrix, and AO-80/XNBR composites had only one Tg, adding AO-80could greatly improve the Tg of AO-80/XNBR composites. The Tg of AO-80/XNBR composites could raise from-21.3℃to7.5℃when AO-80was added from0phr to100phr, Tg of the composites was improved29℃, the reason why was that there existed a lager number of strong hydrogen bond between hydroxyl of AO-80and cyano of XNBR. In other words, the addition of AO-80improved the Ttrans of XNBR, that was to say, by changing the dosage of the AO-80could change Ttrans in a certain temperature range. AO-80/XNBR composites had excellent shape memory properties, the shape fixed rate Rf was higher than90%and shape recovery rate was higer than80%, while the AO-80/XNBR composite kept excellent shape memory properties in a wide range of strain and shape memory properties of AO-80/XNBR composite material had high repeatability.(2)AO-80/NBR composites were successfully prepared, the study showed that, AO-80and NBR had good compatibility, there was no AO-80gather phase found in NBR matrix, and AO-80/NBR composites had only one Tg, adding AO-80could greatly improve the Tg of AO-80/NBR composites, the Tg of AO-80/NBR composites could raise from-12.7℃to12.3℃when AO-80was added from0phr to100phr, Tg of the composites was improved26℃, the reason why wasthat there existed a lager number of strong hydrogen bond between hydroxyl of AO-80and cyano of NBR. In other words, the addition of AO-80improved the Ttrans of NBR, that was to say, by changing the dosage of the AO-80could change Ttrans in a certain temperature range. AO-80/NBR composites had excellent shape memory properties, the shape fixed rate Rf was higher than90%and shape recovery rate was higer than80%, while the AO-80/NBR composite kept excellent shape memory properties in a wide range of strain.(3)AO-80/ACM composites were successfully prepared, the study showed that, ACM and AO-80had good compatibility, there was no AO-80gather phase found in ACM matrix, andAO-80/ACM composites had only one Tg, adding AO-80could greatly improve the Tg of AO-80/ACM composites, the Tg of AO-80/ACM composites could raise from-11℃to10℃when AO-80was added from0phr to100phr, Tg of the composites was improved22℃, the reason why was that there existed a lager number of strong hydrogen bond between hydroxyl of AO-80and ester base of ACM. In other words, the addition of AO-80improved the Ttrans of ACM, that was to say, by changing the dosage of the AO-80could change Ttrans in a certain temperature range. AO-80/ACM composites had excellent shape memory properties, the shape fixed rate Rf was higher than90%and shape recovery rate was higer than80%, while the AO-80/ACM composite kept excellent shape memory properties in a wide range of strain and shape memory properties of AO-80/ACM composite material had high repeatability.