Determination of PVDC Coating of PVC/PE/PVDC Composite Sheet for Solid Preparation

OBJECTIVE To develop a method for determination of PVDC coating of PVC/PE/PVDC composite sheet for solid preparation. METHODS Cut off 5 pieces of samples of 10 cm×10 cm, immersed in acetone to separate PE/PVDC composite layer from PVC layer. Dried PE/PVDC composite laied in 80℃ for 2 h, then laied in 23℃ for 4 h and weighed. Immersed PE/PVDC composite layer in THF, dissolved PVDC and obtained PE layer, dried PE layer in 80℃ for 2 h, then laied in 23℃ for 4 h and weighed. The difference of two weights was PVDC coating amount. Then calculated the PVDC coating (g·m^-2). RESULTS Determination results of PVDC coatings of 5 batch samples were consistent with labelled PVDC coating and deviation was within ±5%. CONCLUSION This method is accurate, sensitive, it can be used for determination of PVDC coating of PVC/PE/PVDC composite sheet for solid preparation.