Polyethylene etching

Figure 11.15 Transmission electron micrographs of replicas of polyethylene etched with permanganic acid. Micrographs of M. T. Conde Braha, Dept of Polymer Technology, Royal Institute of Technology, Stockholm.

Blais et al. used ATR to investigate etching of high-density polyethylene... 

Figure 14 shows the ATR spectrum of the etched polyethylene surface treated with a chronic acid group [76]. Absorption bands due to surface treatment appear at 3300, 1700, 1260, 1215, and 1050 cm". The band at 3300 cm represents the absorption due to the hydroxyl group and that at 1700 cm " is due to the carbonyl group. The bands at 1260, 1215, and 1050 cm are all due to the alkyl sulfonate group. 

The data of Table II indicate that the etch rates for CB and its "homologues"—TP, CO (or TO), and EPM—tend to increase monotonically with a decrease in vinylene (-CH=CH-) unsaturation. The elastomeric EPM was chosen instead of crystalline polyethylene as a model for the fully saturated CB to avoid a morphology factor in etch rates, as was observed with crystalline TB. The difference in etch rates for the partially crystalline TO and the elastomeric CO (ratio of about 1.2 1.0) is attributable more to a morphology difference between these polyoctenamers than to the difference in their cis/trans content. Cis/trans content had likewise no perceptible effect on etch rates in the vinyl-containing polybutadienes (see Table I) if there was a small effect, it was certainly masked by the dominant effect of the vinyl groups. 

Fig. 19 Transmission electron micrograph of a replicate of permanganic-etched polyethylene. Scale bar represents 0.5 pm. Courtesy of M. T. Conde Brana...

Fig. 20 Transmission electron micrograph of permanganic-etched linear polyethylene fraction crystallised at 130.4 °C for 27 days. Courtesy of D.C. Bassett. From [46] with permission from the Royal Society of London, UK...

Fig. 22 Transmission electron micrograph of permanganic-etched branched polyethylene crystallised at 120 °C for 1 min showing dominant S-shaped lamellae. From Patel and Bassett [54] with permission from Elsevier, UK...

Fig. 28 Scanning electron micrograph of high density polyethylene first isothermally crystallised at 128 °C and then rapidly cooled to room temperature. The sample was etched with hot p-xylene to remove the material crystallising in the cooling phase. Scale bar represents 20 pm. From Gedde and Jansson [154] with permission from Elsevier, UK...

Fig. 20 a Change in adhesion forces measured by SFM using chemically modified tip during the time-dependent etching process of polyethylene films, b Adhesion titration curves of PE films unmodified ( ) and etched with chromic acid for 45 min ( )... 

Membranes with very regular pores of sizes down to around 10 nm can be prepared by track-etching [10], and, in principle, those membranes can be used for the fractionation of macromolecules in solution. A relatively thin (<35 pm) polymer film (typically from polyethylene terephthalate)/PET/or aromatic polycarbonate/PC/) is first bombarded with fission particles from a high-energy source. These particles... 

Other recent applications of AFM-SECM included the study of the iontophoretic transport of [Fe(CN)6]4 across a synthetic track-etched polyethylene terephthalate membrane by Gardner et al. [193]. They made the structure and flux measurements at the single pore level and found that only a fraction of candidate pore sites are active in transport. Demaille et al. used AFM-SECM technique in aqueous solutions to determine both the static and dynamical properties of nanometer-thick monolayers of poly(ethylene glycol) (PEG) chains end-grafted to a gold substrate surface [180]. 

Polyethylene terephthalate cannot be solvent-cemented or heat-welded. Adhesives are the prime way of joining PET to itself and to other substrates. Only solvent cleaning of PET surfaces is recommended as a surface treatment. The linear film of polyethylene terephthalate (Mylar) provides a surface that can be pretreated by alkaline etching or plasma for maximum adhesion, but often a special treatment such as this is not necessary. An adhesive for linear polyester has been developed from a partially amidized acid from a secondary amine, reacted at less than stoichiometric with a DGEB A epoxy resin, and cured with a dihydrazide.72... 

A— Polyethylene film nucleated and solidified in contact with etched aluminum surface (subsequently dissolved from substrate)... 

Transcrystalline region (TCR) polyethylene generated at 175°C. for V2 hour against etched aluminum (substrate removed by dissolution)... 

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