Such as those containing wax, oil, asphalt more charged the media to prevent crystallizationof the media, to ensure efficient operation of the automatic control system.
如含蜡质、沥青较多的石油等被控介质，防止介质的结晶，确保自控系统高效运转。
2
The characteristic groups of polymeric pour point depressant(PPD)were analyzed by FT-IR and NMR techniques. The crystallization properties of various types of wax and PPD were measured by XRD.