The present invention is directed to a method of preparing an actuator capable of being repeatedly and reversibly shifted between two freestanding shapes (A, B) under stress-free conditions upon varying a temperature between a temperature T.sub.low and a temperature T.sub.sep. The method comprising the steps: (a) providing an actuator consisting of or comprising a covalently or physically cross-linked polymer network, the polymer comprising a first phase having a thermodynamic phase transition extending in a temperature range from T.sub.trans,onset to T.sub.trans,offset, and an elastic phase having a glass transition temperature T.sub.g, with T.sub.g<T.sub.trans,onset, the polymer having an initial shape; (b) deforming the polymer to a deformation shape at a temperature T.sub.prog by applying a stress, where the deformation is adapted to align chain segments of the polymer; (c) setting the polymer to a temperature T.sub.low with T.sub.lowT.sub.trans,onset under maintaining the stress as to provide a solidified state of the polymer domains associated with the first phase; (d) heating the polymer to a predetermined separation temperature T.sub.sep, with T.sub.trans,onset<T.sub.sep<T.sub.trans,offset, under stress-free conditions as to melt first polymeric domains (AD) of the first phase having a transition temperature in the range between T.sub.trans,onset and T.sub.sep and to maintain second domains (SD) of the first phase having a transition temperature in the range between T.sub.sep and T.sub.trans,offset in the solidified state, thus implementing shape A, where shape A geometrically lies between the initial shape provided in step (a) and the deformation shape applied in step (b) and shape B is the shape at T.sub.low and lies geometrically between shape A and the shape of deformation of step (b).

The invention provides a heat-shrinkable polyester film with high mechanical strength in a width direction that is orthogonal to the main shrinking direction and high tensile rupture elongation in the film width direction after being subjected to an aging treatment in a high-temperature environment. The heat-shrinkable polyester film is made from a polyester resin containing ethylene terephthalate as the main component and a monomer component that can serve as an amorphous component in an amount of 0 mol % or more and less than 1 mol % relative to the total amount of polyester resin components.

A substrate includes a double-network polymer system including a cross-linked, covalently-bonded polymer and a reversible, partially ionicly-bonded polymer, wherein the substrate has a moisture level less than or equal to 15 percent of the total weight of the substrate, and wherein the substrate includes a latent retractive force. A method for manufacturing a substrate includes producing a double-network hydrogel including a cross-linked, covalently-bonded polymer and a reversible, ionicly-bonded polymer; elongating by force the double-network hydrogel in at least one direction; dehydrating while still elongated the double-network hydrogel to form a substantially-dehydrated double-network polymer system; and releasing the force to produce the substrate.

Provided herein are systems and methods for polymerizing and programming a liquid crystal polymer, including a liquid crystal elastomer (LCE) with two-way shape-memory via a stepped or self-limiting reaction. In the described method, the reaction may be stepped to achieve different aspects of the two-way shape-memory effect in the produced LCE. In one embodiment, the method creates a polydomain LCE body with a completed thiol-acrylate Michael addition reaction polymerization. The method may further crosslink the polydomain LCE body under a stimulus, thereby locking a domain state in a portion of the polymer. A two-way shape-memory effect of the LCE may thereafter be programmed and locked into the LCE the second stage polymerization reaction. The self-limiting reaction allows for unprecedented control over LCE domain states and cross-linking densities, as well as the resultant mechanical and optical properties of the LCE formed.

Multi-shape products of the present disclosure comprise two components: a matrix component and a fiber component that is embedded or otherwise disposed in the matrix component. The matrix component exhibits certain shape memory properties. The fiber component interpenetrates the matrix component to facilitate fixing of the multi-shape product in various temporary shapes.

The disclosure provides a system of thermoset shape memory poly(urea-urethane) with permanent reshaping property and its application. The breakthrough of the present invention is that the reshaping temperature can be tuned in a wide range by incorporation of urea bonds into the polymer network. The permanent shape for shape memory poly(urea-urethane) can be repeatedly and cumulatively reshaped at certain temperature, largely facilitating the fabrication of complex structures.

The present invention discloses the fabrication and application of a shape memory polymer possessing transesterification-induced permanent reshaping. The ester-containing crosslinked polymer is obtained by crosslinking ester bearing polymer precursors or by reaction of monomers which yield ester bonds. The transition temperature falls between 20-150 C. The reshaping temperature is tuned by catalyst amount and should be 20 C. above the transition temperature. The breakthrough of the present invention lies in integrating shape memory effect and plastic deformation into the same polymer and triggering the respective function at different occasions. The permanent shape of as synthesized polymer could be modified arbitrarily and cumulatively. Therefore, the hierarchical structure which could not otherwise be obtained due to the limit of mold fabrication process should expand the practical application of SMPs.

The present invention relates to a process for producing a shaped body (SB) comprising the preparation of a thermoplastic polyurethane, the production of a shaped body (SB*) from the thermoplastic polyurethane, the heating of the shaped body (SB*) to a temperature below the temperature of permanent deformability of the shaped body (SB*) and above the switching temperature of the thermoplastic polyurethane, the expanding of the heated shaped body (SB*) to obtain a shaped body (SB), and the cooling of the shaped body (SB) to a temperature below the switching temperature of the thermoplastic polyurethane, and to the shaped bodies obtained or obtainable by such a process. The present invention further relates to the use of a thermoplastic polyurethane for production of a shaped body having shape memory effect within a temperature range from 20 C. to 120 C.

The present invention provides a heat shrinkable multilayer film which has excellent printability and also has good finish quality after attachment. The present invention relates to a heat shrinkable multilayer film, including front and back layers each containing a polyester resin, an interlayer, and adhesive layers, the front and back layers and the interlayer being stacked with the adhesive layers interposed therebetween. The interlayer contains a styrene homopolymer and a plasticizer. The interlayer contains the plasticizer in an amount of 5 to 35% by weight.

A method of installing a heat shrink cover around a component includes providing the heat shrink cover having an inner sleeve and an outer sleeve, the inner sleeve is a heat shrink sleeve, and attaching an electrical heating system to an outer surface of the outer sleeve. The inner sleeve and the outer sleeve are arranged around the component, with the outer sleeve at least partially encompassing the inner sleeve. The electrical heating system is energized to heat-recover the inner sleeve.