In this paper, a series of semi-interpenetrating polymer network materials based on poly ((2-dimethylamino) ethyl methacrylate)/poly (N, N-diethylacrylamide) (PDMAEMA/PDEA) were synthesized at room temperature. The influence of this additive on the property of resulting PDEA materials was investigated and characterized. The glass transition temperature (Tg) of the semi-IPN materials was observed by Differential Scanning Calorimetry (DSC). Compared to PDEA, the semi-IPN materials exhibited excellent mutative values in response to an alternation of the temperature, and showed fast swelling and deswelling rates in response to temperature change, which suggests that these materials have potential application as thermal infrared camouflage materials.