Crosslinking degree analyzerIt has excellent flexibility, impact resistance, elasticity, optical transparency, low-temperature bending, adhesion, environmental stress cracking resistance, weather resistance, chemical resistance, and heat sealing. The performance of the crosslinking degree analyzer mainly depends on the molecular weight (expressed as melt index MI) and the content of vinyl acetate (expressed as VA). When MI is constant, the elasticity, flexibility, adhesion, solubility, and transparency of VA increase, while the content of VA decreases, approaching the performance of polyethylene. When the VA content is constant, the decrease in MI leads to a decrease in softening point, while the processability and surface gloss improve, but the strength decreases and the molecular weight increases, which can improve impact resistance and stress cracking resistance.
　　Crosslinking degree analyzerCrosslinking degree test:
1. Instrument and apparatus: ground mouth round bottom flask; Grinding reflux condenser tube; Electric heating sleeve or electric heating oil bath equipped with temperature controller; Vacuum oven; Stainless steel wire mesh.
2. Reagent: Xylene A, R-grade
3. Sample preparation: Take a piece of adhesive film, stack the TPU/adhesive film/glass, cure and crosslink according to the usual one-time curing process, and cut the crosslinked adhesive film into small pieces for later use.
4. Inspection steps
Wash the stainless steel mesh bag, dry it, and weigh it as W1;
Take 0.5g ± 0.01g of the sample, place it in a stainless steel wire mesh bag, and weigh it as W2;
Seal the bag opening to make a sample bag, weigh W3;
The sample package is suspended in a flask under a reflux condenser tube using fine wire. 1/2 xylene solvent is added to the flask and heated to around 140 ℃. When the solvent boils and refluxes for 5-6 hours, the reflux rate is maintained at 20 to 40 drops per minute;
Cool and remove the sample package, hang it to remove solvent droplets, then place it in a vacuum oven with a temperature controlled at 140 ℃ and a vacuum degree of 0.08Mpa. Dry for 3 hours to remove the solvent;
Remove the sample package from the vacuum oven, cool it in a dryer for 20 minutes, and weigh it as W4.
Result calculation: C=[1- (W3-W4)/(W2-W1)] x100.
Where:
C-degree of adhesion (%);
W1- Empty bag weight (g);
W2- Weight of the bag containing the sample (g);
W3- Sample package weight (g);
W4- Sample package weight (g) after solvent extraction and drying.