Search results
Results from the WOW.Com Content Network
Many milk bottles have integral handles. Milk bags are also in use. The milk is sold in a plastic bag and put into a pitcher for use. Larger bags are the inner bladder of a bag-in-box, sometimes used for institutional dispensing. Small individual containers of milk and cream are often thermoformed or injection molded and have a peelable lid ...
Molecular weights of 130 kDa can be obtained this way. Even higher molecular weights can be attained by carefully crystallizing the crude polymer from the melt. Carboxylic acid and alcohol end groups are thus concentrated in the amorphous region of the solid polymer, and so they can react. Molecular weights of 128–152 kDa are obtainable thus ...
A common form of such storage is the biscuit tin. See Canning. Refrigerator. Perhaps the most ubiquitous domestic item of food storage is the fridge or fridge-freezer in which a wide variety of foodstuffs are contained and preserved through the use of low temperatures. Disposable
The degradation process is erosive and appears to take place in two steps during which the polymer is converted back to its monomer glycolic acid: first water diffuses into the amorphous (non-crystalline) regions of the polymer matrix, cleaving the ester bonds; the second step starts after the amorphous regions have been eroded, leaving the ...
Polymer morphology is a microscale property that is largely dictated by the amorphous or crystalline portions of the polymer chains and their influence on each other. Microscopy techniques are especially useful in determining these microscale properties, as the domains created by the polymer morphology are large enough to be viewed using modern ...
[1] [better source needed] The practical significance of tacticity rests on the effects on the physical properties of the polymer. [not verified in body] The regularity of the macromolecular structure influences the degree to which it has rigid, crystalline long range order or flexible, amorphous long range disorder.
The polymer is dissolved in an organic solvent (such as dichloromethane). Powdered drug and filler (typically an inert sugar) are added to the liquid solution and rapidly mixed to obtain a homogeneous mixture. The drug-filler-polymer mixture is then cast into a mold at −80 °C and freeze-dried until solid.
Polymer chain length depends on the ratio of reactants. HOCH 2 CH 2 OH + n(CH 2 CH 2 O) → HO(CH 2 CH 2 O) n+1 H. Depending on the catalyst type, the mechanism of polymerization can be cationic or anionic. The anionic mechanism is preferable because it allows one to obtain PEG with a low polydispersity. Polymerization of ethylene oxide is an ...