Reasearch On Preparation Of Polyurethane-Based Carbon Nanocomposites And Their Light Actuation Behavior

Shape memory polymers （SMP） as an emerging class of smart polymers are widelyused in a variety of fields, including smart textiles, actuators, intelligent medicaldevices and micro-systems. The heat, light, electric field, magnetic field and moistureare common external stimulus to shape memory of SMP. The light-induced SMP havedrawn the considerable attention because the light is environmental friendly, safe andavailable to remote and wireless control.In this paper, the sulfonated graphene （GO-SO₃H） and sulfonated carbon nanotube（CNT-SO₃H） were prapared by surface modification and oxidation reduction method.A series of TPU/GO-SO₃H/CNT-SO₃H nanocomposites with light actuation behaviorwere synthesized by adding GO-SO₃H and CNT-SO₃H hybrid fillers intothermalpolastic polyurenthane （TPU） using solution blending method. The effect ofdifferent ratios of GO-SO₃H and CNT-SO₃H in TPU and their morphologies in TPUmatrix on thermal conductivity and light actuation performance was studied.The results show that GO-SO₃H and CNT-SO₃H with high level of sp2carbon-network structures is homogeneously dispersed in TPU. They can effectivelyconvert light to thermal energy for light actuation behavior. Compared toTPU/GO-SO₃H and TPU/CNT-SO₃H nanocomposites, GO-SO₃H/CNT-SO₃H hybridfillers can form three-dimensional interconnected networks in TPU matrix, whichimproves thermal conductivity and leads to outstanding light actuation performance.The energy densities of all nanocomposites are over1000J/g. When the weight ratioof GO-SO₃H and CNT-SO₃H is3:1, thermal conductivity reaches1.463W/mK. Itshows the best light actuation performance of lifting a106.6g weight about4.5cminduced by light for18.5s, and the corresponding energy densitie is1141J/g.