The effect of weathering on the fracture energy of hardcoats over polycarbonate

• Published in: Polymer degradation and stability Vol. 75; no. 3; pp. 439 - 446
• Main Authors: Nichols, M.E, Peters, C.A
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.2002; Elsevier Science
• Subjects: Ageing; Applied sciences; Exact sciences and technology; Fracture; Hardcoat; Physical properties; Polycarbonate; Polymer industry, paints, wood; Properties and testing; Technology of polymers; Weathering; Weathering; Fracture; Hardcoat; Polycarbonate; Embrittlement; Cracking; Mechanical properties; Experimental study; Additive; Stabilizer agent; Artificial ageing; Light stabiliser; Measurement method; Exposure time; Fracture energy; Protective coatings; Siloxane polymer; Photochemical degradation
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/S0141-3910(01)00244-0

The effects of accelerated weathering on the brittleness of siloxane-based hardcoats coated on polycarbonate sheet were quantified using fracture energy testing and chemical composition change measurements. The hardcoat containing no ultraviolet light absorber (UVA) showed a faster decrease in the fracture energy as weathering progressed, compared to the hardcoat formulated with UVA. In addition, the rate of weathering induced chemical composition change, as measured by photoacoustic infrared spectroscopy, was greater in the UVA free hardcoat. The decrease in the fracture energy appears to be proportional to the amount of chemical composition change, regardless of whether the hardcoat contains UVA.