Foreword Polyethylene glycol is a polymer based on ethylene oxide and has a wide range of molecular masses. PEGs have good water solubility and can be liquid, semi-solid and solid. Solid PEGs are composed of semi-crystalline and amorphous materials. Mixtures with different degrees of polymerization show extremely complex structural features in both micro and macro fields. The solid PEGs are divided into amorphous regions and crystalline regions. Its crystallinity differs depending on the type of crystal and molecular mass distribution, the thermal history of solid matter and crystallization. According to different crystallization processes, the crystal region is composed of layered crystals and spherical crystals. The layered crystal itself can be divided into two forms: extended chain and folded chain. The latter is metastable with respect to the extended chain. Due to the existence of different crystal forms and different molecular mass distributions, the analysis of the semi-crystallinity of PEGs is very complicated. In the development, operation and application of pharmaceutical and food technology, determining the function of the liquid composition fraction and temperature of pharmaceuticals and foods is very important to characterize their thermomechanical properties and rheology. Only by comparing the liquid composition fraction on the basis of the melting curve can satisfactory results be obtained for all materials and drug samples. When only looking at the melting curve, the evaluation of the composition fraction of the liquid phase allows for subtle effects without explanation. This article mainly studies the melting range of two common polyethylene glycol raw materials: polyethylene glycol 6000 and polyethylene glycol 1500. Fowl Catcher,Stainless Steel Fowl Catcher,Steel Chicken Catcher,Catcher Stainless Steel Hebei Liebang Metal Products Co.,Ltd , https://www.liebangtraptool.com
Polyethylene glycol is compatible with many waxes, gums, oils, starches, and organic solvents, and has a wide range of applications. For example, it can be used as high-quality release agent, metal quenching, detergent for general machinery or household machinery, and heat storage medium for solar collectors in the rubber industry. In the pharmaceutical industry, polyethylene glycol is widely used as a component of water-soluble ointment bases and traumatic soluble ointments. The main uses include ointments, suppositories, creams, etc. It can be used alone or mixed to produce a range of melting points that have a long shelf life and the liquid chromatograph meets the requirements of drugs and physical effects. Suppositories based on PEG are less irritating than traditional grease bases. Characterization (PEGs) by DSC is very important for the quality control of PEGs.