[m2016]

Hi!
What is the exact difference between "acrylic crystals" and "acrylate crystals"?

[P]

I think that acrylic is just a name given to acrylates. 

I could be wrong - which is why I typed 'I think' rather than stating it as a fact, but I have always thought that they were the same.

[DrCMS]

Acrylic usually means made from acrylic acid while acrylate suggests either neutralised polyacrylic acid or made using another monomer such as butyl acrylate etc.

[P]

OK DrCMS -  thanks - but it gives the same polymer though yeah?

What is Poly Methyl Methacrylate? (Polymer of Methy Methacrylate) Is that also considered an acrylic? I thought it might have been. Can we consider all of these acrylates as acrylics?

[DrCMS]

OK DrCMS -  thanks - but it gives the same polymer though yeah?

Sure polyacrylic acid neutralised with NaOH gives sodium polyacrylate but obviously polyacrylic acid and polybutylacrylate are different. 

What is Poly Methyl Methacrylate? (Polymer of Methy Methacrylate) Is that also considered an acrylic?

No that is a methacrylate.  Methacrylate are stiffer than acrylates.

Can we consider all of these acrylates as acrylics?

I would not do but other people who do not work with these types of materials might do because they do not think they are different enough.

[m2016]

Is "acrylic" just the proper adjective corresponding to the noun "acrylate"?

[Arkcon]

Not really.  Try to figure out your question by using the context, which only you have, so far.  If the substance is called Acrylic^TM -- notice the capitalization, and I tacked on the trademark, then you're dealing with a Trade name, but sometimes they lose the capitalization. 

The polymer, polymethymethacrylate is a pretty common one.  In a block, it may be called Acrylic, in a sheet, it may be called Plexiglass^TM.  Or you cam call it an acrylic window, if you want.

The -ate is a common thing we do in science.  The acid we call acrylic acid.  But the acid isn't what makes it a plastic, so we call the subunits acrylate.  We do this with other organic acids to, for example, pyruvic acid -- pyruvate, or folic acid -- folate.

[m2016]

Following terms seem to be common:

Adjectival use:
"acrylic acid" (397.000 hits with google),
"acrylate acid" (21.300 hits),

"acrylic polymer" (404.000 hits),
"acrylate polymer" (220.000 hits),

"acrylic copolymer" (342.000 hits),
"acrylate copolymer" (364.000 hits),

PAA := polyacrylic acid,
EAA := ethylene-acrylic acid,

Substantival use:
PBAK := poly butyl acrylate,
polystyrene := poly methyl methacrylate.

The proper criterion for selecting among both terms (acrylic and acrylate) is still unclear to me.