Rigid High Temperature Heat-Shrinkable Polyimide Tubes with Functionality as Reducer Couplings

Deyan Kong,Xinli Xiao

doi:10.1038/srep44936

Abstract

Flexible and semi-rigid heat-shrinkable tubes (HSTs) have been used in thousands of applications, and here rigid high temperature HSTs are reported for the first time. These rigid HSTs are prepared with shape memory polyimides possessing glass transition temperatures (Tgs) from 182 to 295 °C, and the relationships between Tg and their molecular structures are studied. The polyimide HSTs (PIHSTs) can fix expanded diameters and shrink back to original diameters very well, and the mechanisms of their heat-shrinkage performance are discussed. Their differences from commercially available HSTs in heat-shrinkage are also analyzed. They can withstand low temperature of −196 °C, much lower than those of other HSTs. The PIHSTs can also connect subjects of different sizes by heat-shrinkage and then fix them upon cooling like reducer couplings, and the possible mechanisms of their reducer coupling effect are analyzed. With their unique characteristics, PIHSTs will expand the application areas of HSTs enormously.

Highlights

Heat-shrinkable tubes (HSTs) are polymer tubes that can be expanded at high temperature and maintain the expanded diameters at low temperature[1,2,3]
The rigid high temperature heat-shrinkable tubes (HSTs) in the current report are prepared with shape memory polyimides, and the two-step polymerization process of these polyimides are shown in the supporting information as Figs S1–S4, respectively
The polyimide HSTs (PIHSTs) prepared with homopolyimides of BPADA/BAB, ODPA/BAB and BTDA/BAB are labeled as PIHST01, PIHST02 and PIHST03, respectively

Summary

Shrinkable Polyimide Tubes with

Functionality as Reducer Couplings received: 28 September 2016 accepted: 15 February 2017 Published: 20 March 2017. The polyimide HSTs (PIHSTs) can fix expanded diameters and shrink back to original diameters very well, and the mechanisms of their heat-shrinkage performance are discussed Their differences from commercially available HSTs in heat-shrinkage are analyzed. Available high temperature HSTs are unable to hold or fix heavy load since they are flexible or semi-rigid, and in some cases supporting frames are needed for the subjects concerned with HSTs. the supporting frames may lead to much inconvenience due to their extra weight and space occupied, especially for delicate or elaborate equipments such as advanced electrical and aerospace devices. The PIHSTs can connect and fix different heavy subjects through heat-shrinkage, and the possible mechanisms of their reducer coupling effect were analyzed With their unique properties, the rigid PIHSTs will find applications in many fields

Results

Methods

Additional Information