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PMMA(polymethyl methacrylate) and acetal have significant differences in chemical properties, physical properties, application fields and so on. Here is a detailed explanation of the difference between the two:
Chemical property
PMMA:
PMMA is a polymer made from methyl methacrylate monomer by polymerization.
The chemical name is polymethyl methacrylate, referred to as PMMA, also known as acrylic or plexiglass.
The molecular chain of PMMA is formed by free radical polymerization or ionic polymerization of methyl methacrylate monomer. The main chain of PMMA contains ester group and methyl group.
Acetal:
Acetals are a class of organic compounds, formed by the condensation of one molecule of aldehyde with two molecules of alcohol.
The general structure of the acetal as RR 'C (OR' ') (OR ' ' '), including R and R 'for hydrogen, but the' R 'and R' ' 'can't is hydrogen.
Acetals are stable to bases, but when warm in dilute acids they undergo hydrolysis reactions to form the original aldehydes and alcohols.
Physical property
PMMA:
PMMA has a high transparency, light transmittance of up to 92%, known as "plastic crystal".
It has good mechanical properties, impact strength is about 16 times that of ordinary glass, wear resistance and weather resistance are also good.
The glass conversion temperature of PMMA is about 105°C, and the melting point is low, about 130\~140°C.
The density is low, about 1.15\~1.19 g/cm³, which is about half of the glass.
Acetal:
The physical properties of acetals vary depending on the specific compound, but generally have a pleasant aroma.
Acetals are less stable than ethers and tend to polymerize when placed.
Acetals are easily hydrolyzed to the original aldehydes and alcohols under the catalysis of acids.
Application field
PMMA:
PMMA is mainly used in the construction field to make various doors and Windows, partitions, lenses, etc.
In the automotive field, it is used to make lamps, rearview mirrors, windshields, etc.
In the field of electronics, it is used to make display screens, touch screens, light guides, etc.
In the medical field, it is used to make artificial joints, teeth, orthopaedic implants, etc.
In the aviation field, it is used to make aircraft portholes, seat covers, etc.
Acetal:
Because of its stability and aromatic smell, acetal is used in the spice industry as an additive for food and cosmetics.
Acetals are also important raw materials for organic synthesis.
In summary, PMMA and acetal have significant differences in chemical properties, physical properties and application fields. As a kind of polymer, PMMA has excellent performance in transparency and mechanical properties, and is widely used in construction, automobile, electronics, medical and other fields. As a kind of organic compound, acetal plays an important role in the fields of flavor, food, cosmetics and organic synthesis.