Herein, the terminal groups of the crude oxymethylene copolymer, and the stabilization treatment of the unstable terminal groups will be explained. The stable terminal groups of the crude oxymethylene copolymer are alkoxy groups such as methoxy groups (—OCH 3 ) and the like, and hydroxyalkoxy groups with a carbon number of 2 or more such as hydroxyethyl groups (—CH 2 CH 2 OH), hydroxybutyl groups (—CH 2 CH 2 CH 2 CH 2 OH) and the like. On the other hand, the unstable terminal groups of the crude oxymethylene copolymer are hemiacetal terminal groups (hydroxymethoxy terminal groups, also called hemiformal terminal groups, represented by —OCH 2 OH) and formyl terminal groups (represented by —CHO).
In chemistry applications, although the polymer is often suitable for the majority of glassware work, it can succumb to catastrophic failure. An example of this would be using the polymer clips on hot areas of the glassware (such as a flask to column, column to head or head to condenser joint during distillation). As the polymer is sensitive to both chlorine and acid hydrolysis, it may perform very poorly when exposed to the reactive gases, particularly hydrogen chloride. Failures in this latter instance can occur with seemingly unimportant exposures from well sealed joints, and do so without warning and rapidly (the component will split or fall apart). This can be a significant health hazard as the glass may open or smash. Here, PTFE or a high grade stainless steel may be a more appropriate choice.