Use of a dye-labeled ethylene-butene copolymer as a tracer in laser scanning confocal fluorescence microscopy studies of thermoplastic olefins

• Published in: Journal of polymer science. Part A, Polymer chemistry Polymer chemistry, 2001-01, Vol.39 (1), p.239-252
• Main Authors: Tong, Jiang-Dong, Moffitt, Matthew, Huang, Xiaoyu, Winnik, M. A., Ryntz, Rose A.
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical modifications; Chemical reactions and properties; dye-labeled polymer; ethylene-butene rubber; Exact sciences and technology; laser scanning confocal fluorescence microscopy; Organic polymers; Physicochemistry of polymers; thermoplastic polyolefin
• ISSN: 0887-624X; 1099-0518
• DOI: 10.1002/1099-0518(20010101)39:1<239::AID-POLA270>3.0.CO;2-N

A benzothioxanthene‐labeled ethylene‐butene rubber has been synthesized and tested as a potential fluorescent tracer for the impact modifier (IM) phase in laser scanning confocal fluorescence microscopy (LSCFM) studies of thermoplastic olefin (TPO) morphology. The amino‐functional Hostasol Yellow derivative HY‐DP reacts with maleated EBR‐28 to give a good labeling yield (ca. 70%) and a dye concentration of 0.051 mmol/g, when the maleated rubber is first refluxed over molecular sieves and the reaction purged with N2. Without pretreatment of the rubber and N2 purging, a lower labeling yield (0.036 mmol dye/g) is obtained and the labeled product tends to undergo crosslinking at 240 °C and subsequent dye detachment when the crosslinked gel is hydrolyzed. LSCFM studies reveal HY‐labeled EBR to be completely miscible and evenly dispersed in the unlabeled EBR‐9 of model TPO blends. Moreover, the HY‐labeled EBR provides good fluorescence contrast between the IM droplets and the PP matrix in the TPO blend PP/EBR (80/20) (w/w) + 3 wt % labeled polymer with respect to EBR. Imaging of IM droplets down to 40 μm below the film surface of this blend has been demonstrated. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 239–252, 2001 A benzothioxanthene‐labeled ethylene‐butene rubber was synthesized and tested as a potential fluorescent tracer for the impact modifier (IM) phase in laser scanning confocal fluorescence microscopy (LSCFM) studies of thermoplastic olefin (TPO) morphology. The amino‐functional dye derivative HY‐DP was reacted with maleated EBR‐28 (28 mol % butene) to give a labeled polymer containing 0.051 mmol dye per gram of polymer. LSCFM studies revealed that HY‐labeled EBR‐28 is miscible in the unlabeled EBR‐9 (9 mol % butene) of model TPO blends. Moreover, the HY‐labeled EBR provides good fluorescence contrast between the IM droplets and the PP matrix, making it an effective tracer for the impact modifier.