ESC resistance of commercial grade polycarbonates during exposure to butter and related chemicals

• Published in: Polymer degradation and stability Vol. 93; no. 8; pp. 1486 - 1495
• Main Authors: Kjellander, Carina K., Nielsen, Tenna B., Ghanbari-Siahkali, Afshin, Kingshott, Peter, Hansen, Charles M., Almdal, Kristoffer
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-08-2008; Elsevier
• Subjects: Ageing; Applied sciences; ESC; Exact sciences and technology; FTIR; Hansen solubility parameters; Lipid resistant; MALDI-TOF; Physical properties; Polycarbonate; Polymer industry, paints, wood; Properties and testing; Technology of polymers; Lipid resistant; Hansen solubility parameters; ESC; MALDI-TOF; Polycarbonate; FTIR; Butter; Experimental study; Triglyceride; Fatty acids; Cyclic ether polymer; Stress cracking; Fat resistance; Reaction mechanism; Solubility parameter; Artificial ageing; ESC,Polycarbonate,Lipid resistant,MALDI-TOF,FTIR,Hansen solubility parameters; Chemical stress; Chemical properties; Exposure time; Thermodynamic properties; Conformational transition
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2008.05.011

Three commercial grades of polycarbonates (Lexan
® 144, Lexan
® 104 and Makrolon Rx1805) were studied with respect to resistance to environmental stress cracking (ESC) when exposed to butter and related chemicals. The polycarbonates (PCs) were extensively characterised to determine whether differences in ESC resistance could be related to their structural or chemical properties. MALDI-TOF mass spectrometry revealed that Makrolon Rx1805 contains a low molar mass material characterised as poly(propylene glycol)p, which was confirmed by ATR-FTIR and
1H NMR. Some “non-absorbing” chemicals, such as butter, cause the PCs to be less resistant to ESC under stress. The reason for this is that these chemicals and the PCs have sufficiently similar Hansen solubility parameters to allow surface conformational changes even though absorption is non-existent or extremely small. ATR-FTIR was used to detect changes in molecular structure in the PC surfaces.