Low-density Polyethylene (PE) were synthesized with poly[butyl methacrylate (B)-co-styrene (S)], poly(dodecyl methacrylate(D)-co-styrene] and poly(ethyl hexyl methacrylate (EH)-co-styrene] copolymers in order to obtain IPN-like networks. Different S/methacrylate copolymer molar ratios going from 0/100 up to 60/40, a molar percentage of 1.0% of 1,4-butanedioldimethacrylate (b) and 3 wt% of 2,5-dimethyl-2,5-di-(tert-butyl peroxy) hexane (Luperox 101) were used. The samples were analyzed at RT by WAXS, swelling in CCl4 and mechanical tensile tests. Dynamic-mechanical tests and optical investigations were performed in a temperature range between RT and 180degreesC. All the IPN types showed optical reversible transitions (transparency-to opacity and vice versa) with varying temperature, due to a refractive index (RI) matching-mismatching of PE and copolymer networks. The copolymer chemical nature as well as its composition affected sensitively most of the analyzed properties.