Structure And Properties Of Waterborne Shape Memory Polyurethane

The research of shape memory polymers has become the hottest field of materials, and they have attracted more and more attentions from academia or industry. The shape polyurethane was hailed as "The most research and the value smart polymers". In this paper, the water-borne shape memory polyurethane is a breakthrough on traditional solvent-based shape memory polyurethane, and have superior performance and broad application areas.This paper stared from the impact of structure on performance of water-borne shape memory polyurethane,and researched hard segment structure, hard segment content, chain extender structure, crosslinker content, soft segment structure and molecular weight of the soft segment on the influence of water-borne shape memory polyurethane. The main content of the paper include the following points:1. Effect of hard segment structure,content, chain extender and crosslinker content on structure and performance of waterborne shape memory polyurethane.A series of crosslinking water-borne shape memory polyurethane with different hard segment content was prepared using polycaprolactone (PCL2000) as the crystallizable soft segment and isophorone diisocyanate(IPDI) as the hard segment. Effect of hard segment content on the structure and properties of shape memory polyurethane and its application on the treatment of fabric have been studied by FTIR, GPC, DSC, water vapor permeability, shape memory performance test and other properties tests. It was found that with increase of hard segment content, the melting temperature of water-borne shape memory polyurethane increased, the crystallinity decreased, the shape recovery ratio first increased and then reduced. The result showed that when the hard segment is28.6%, the shape of the maximum recovery rate is94%. In the aspect of fabric coatings, it was found that with increase of hard segment content, the water permeability reduced and with the temperature increased, the water permeability increased. The recovery angle of the treated fabric bigger than the recovery angle of the untreated fabric.A series of crosslinking water-borne shape memory polyurethane with different hard segment sreucture was prepared using polycaprolactone (PCL2000) as the crystallizable soft segment and isophorone diisocyanate(IPDI) or toluene diisocyanate(TDI) or diphenylmethane diisocyanate(MDI)as the hard segment. It was found that comparing to the IPDI water-borne shape memory polyurethane, TDI and MDI has super effect shape memory behavior and crystallinity. The MDI is biggest and TDI next. This is due to the structure of hard segment itself, and the existence of benzene make the gathered force of hard segment more strong, that make separation degree of soft and hard phase become increased, and the shape reply effect increased.A series of liner water-borne shape memory polyurethane with polycaprolactone (PCL2000) as the crystallizable soft segment and isophorone diisocyanate(IPDI) as the hard segment and DE, ED, BD, HD as chain extender. It was found that the shape recovery ratio which biggest were synthesized by the ED and BD. Repeatedly cycle tensile tests show that the stability of the DE is best. Comparing to the crosslinked waterborne shape memory polyurethane, the linear water-based shape memory polyurethane shape memory performance is poor.A series of crosslinking water-borne shape memory polyurethane with different crosslinker content was prepared using polycaprolactone (PCL2000) as the crystallizable soft segment and isophorone diisocyanate(IPDI) as the hard segment. It was found that with increase of crosslinker content, the crystallinity first increased and then reduced,but the shape recovery rate increased.2. Effect of soft segment structure and molecular weight of the soft segment on structure and performance of waterborne shape memory polyurethane.A series of liner water-borne shape memory polyurethane with different soft structure was prepared using poly(ethylene adipate)(PEAG-2000) or poly(butylene adipate)(PBAG-2000)or poly(hexylene adipate)(PHAG-2000) as the crystallizable soft segment and isophorone diisocyanate(IPDI) as the hard segment. It was found that crystallinity of PHAG was the largest, followed by PBAG, PAGE was minimum. The shape memory effect is also to follow this law.A series of crosslinking water-borne shape memory polyurethane with different molecular weight of the soft segment was prepared using polycaprolactone (PCL-2000,PCL-3000.PCL-5000) as the erystallizable soft segment and isophorone diisocyanate(IPDI) as the hard segment. It was found that with the increase of molecular weight of the soft segment, the melting temperature of water-borne shape memory polyurethane increased, the crystallinity increased,the shape recovery ratio increased, the water permeability reduced.