Highly Cross-Linked and Stable Shape-Memory Polyurethanes Containing a Planar Ring Chain Extender

2020 ◽  
Vol 2 (11) ◽  
pp. 5259-5268
Author(s):  
Qing Luo ◽  
Jing Chen ◽  
Pitchaimari Gnanasekar ◽  
Xiaozhen Ma ◽  
Dongdong Qin ◽  
...  
2017 ◽  
Vol 56 (18) ◽  
pp. 1977-1985 ◽  
Author(s):  
Alireza Eyvazzadeh Kalajahi ◽  
Mostafa Rezaei ◽  
Farhang Abbasi ◽  
Gity Mir Mohamad Sadeghi

2018 ◽  
Vol 21 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Neng-Chiao Weng ◽  
Chih-Fu Wu ◽  
Wen-Chin Tsen ◽  
Cheng-Lung Wu ◽  
Maw-Cherng Suen

2016 ◽  
Vol 4 (32) ◽  
pp. 5394-5404 ◽  
Author(s):  
I. Dueramae ◽  
M. Nishida ◽  
T. Nakaji-Hirabayashi ◽  
K. Matsumura ◽  
H. Kitano

A novel type of shape memory polyurethane (SMPU) with high mechanical properties and biodegradability was constructed using a lactone copolymer (poly(ε-caprolactone-co-γ-butyrolactone), PCLBL), a diol- or triol-based chain extender (1,5-pentanediol, glycerol and 2-amino-2-hydroxymethyl-1,3-propanediol) and a diisocyanate cross-linker (1,6-hexamethylene diisocyanate).


2012 ◽  
Vol 548 ◽  
pp. 115-118 ◽  
Author(s):  
Ernie Suzana Ali ◽  
Syazana Ahmad Zubir ◽  
Ahmad Sahrim

Reactive nanoclay reinforced hyperbranched polyurethane (HPU) nanocomposites have been synthesized with the introduction of palm oil polyol as part of the precursor. The HPU were prepared in a two-step process using polycaprolactonediol, 4,4’-diphenylmethane diisocyanate and 1,4-butanediol as chain extender. Nanoclay was added with the purpose of improving the properties of the pristine polyurethane. The introduction of palm oil polyol is believed to enhance the mixing process between polymer matrix and filler. Thermal, mechanical and shape memory properties of produced HPU were investigated. The results showed that the crystallinity of HPU nanocomposites decreased with introduction of clay particles and that the mechanical and shape memory properties were enhanced with the addition of small amount of reactive nanoclay (up to 3 wt%).


2015 ◽  
Vol 15 (4) ◽  
pp. 14-28 ◽  
Author(s):  
A. Kausar

Abstract In this attempt, segmented poly(urethane urea) was prepared from polycaprolactone triol (soft segment), 1,3- bis(isocyanatomethyl)cyclohexane (hard segment) and 4,5-diaminophthalonitrile (chain extender). Acidfunctionalized nano-diamond was used as nano-filler. The nanocomposites were processed using solution casting and melt blending. Unique morphology was observed by SEM due to generation of crosslinked polyurethane and ND network. The s-PUU/ND 10 depicted 6 % increase in tensile strength compared with m-PUU/ND 10. 10 wt. % ND loading via solution route increased conductivity to 0.089 Scm-1 relative to m-PUU/ND 10 (0.057 Scm-1). Electrical conductivity of nanocomposites was enough to show electroactive shape recovery of 95 % (40 V).


2018 ◽  
Vol 18 (6) ◽  
pp. 1800054 ◽  
Author(s):  
Rong Wang ◽  
Fanjun Zhang ◽  
Weiwei Lin ◽  
Wenkai Liu ◽  
Jiehua Li ◽  
...  

Author(s):  
F. I. Grace

An interest in NiTi alloys with near stoichiometric composition (55 NiTi) has intensified since they were found to exhibit a unique mechanical shape memory effect at the Naval Ordnance Laboratory some twelve years ago (thus refered to as NITINOL alloys). Since then, the microstructural mechanisms associated with the shape memory effect have been investigated and several interesting engineering applications have appeared.The shape memory effect implies that the alloy deformed from an initial shape will spontaneously return to that initial state upon heating. This behavior is reported to be related to a diffusionless shear transformation which takes place between similar but slightly different CsCl type structures.


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