Nova Publishers
My Account Nova Publishers Shopping Cart
HomeBooksSeriesJournalsReference CollectionseBooksInformationSalesImprintsFor Authors
  Top » Catalog » Books » Chemistry including Chemical Engineering » Encyclopedia of Polymer Composites: Properties, Performance and Applications Chapters » My Account  |  Cart Contents  |  Checkout   
Quick Find
Use keywords to find the product you are looking for.
Advanced Search
What's New? more
Fetal Alcohol Syndrome: Recognition, Differential Diagnosis and Long-Term Effects
Shopping Cart more
0 items
Shipping & Returns
Privacy Notice
Conditions of Use
Contact Us
Notifications more
NotificationsNotify me of updates to Development of high performance shape memory polyurethane by cross-linking pp.727-754
Tell A Friend
Tell someone you know about this product.
Development of high performance shape memory polyurethane by cross-linking pp.727-754 $100.00
Authors:  (Yong-Chan Chung, Byoung Chul Chun, Department of Chemistry, The University of Suwon, Hwasung, Korea, and others)
Effect of various cross-linking agents such as glycerol and pentaerythritol on the
shape memory property of polyurethane block copolymer is investigated. The copolymer
was composed of MDI, PTMG-2000, 1,4-butanediol (BD), and cross-linking agent. In
addition to the conventional cross-linking method, shape memory polyurethane (SMPU)
was laterally cross-linked by a polyethyleneglycol (PEG) spacer to remain flexible after
cross-linking, where PEG connected the hydroxyl groups of two polyurethane chains via
MDI as a connecting agent. Phase separation of hard and soft segment is dependent on
cross-linking and hard segment content. Hydrogen bonding and dipole-dipole interaction
between hard segments provides strong interaction between copolymer chains in addition
to chemical cross-linking. As the hard segment content increases, the copolymer shows
better tensile mechanical properties and higher melting temperature of soft segment (Tm).
Effect of glycerol cross-linking on mechanical properties and Tm of soft segment is low
compared to hard segment effect. Significant increase in shape recovery in the case of 30
wt% hard segment copolymer is observed after glycerol cross-linking. The four-way
cross-linking by pentaerythritol also improved the mechanical properties and showed a
very high shape recovery (94%), where the interaction between hard segments is mainly
responsible for the very high shape recovery rate. In the case of flexible cross-linking,
significant increase in maximum stress compared to linear polymer was attained without
any sacrifice in strain. Especially, it is shown in the stress-strain curve that the flexibly
cross-linked SMPU shows similar behavior and superior tensile mechanical properties to
natural rubber. Excellent shape recovery (96.8%) was found and shape recovery time was
3 times faster than linear polymer. The drastic change of the properties of polyurethane
block copolymer is discussed in the point of copolymer chain interaction. 

Available Options:
This Item Is Currently Unavailable.
Special Focus Titles
01.Violent Communication and Bullying in Early Childhood Education
02.Cultural Considerations in Intervention with Women and Children Exposed to Intimate Partner Violence
03.Chronic Disease and Disability: The Pediatric Lung
04.Fruit and Vegetable Consumption and Health: New Research
05.Fire and the Sword: Understanding the Impact and Challenge of Organized Islamism. Volume 2

Nova Science Publishers
© Copyright 2004 - 2020

Development of high performance shape memory polyurethane by cross-linking pp.727-754