𝐓𝐨𝐝𝐚𝐲'𝐬 𝐊𝐍𝐎𝐖𝐋𝐄𝐃𝐆𝐄 𝐒𝐡𝐚𝐫𝐞 : 𝐓𝐲𝐩𝐞𝐬 𝐨𝐟 𝐀𝐜𝐫𝐲𝐥𝐢𝐜 𝐑𝐞𝐬𝐢𝐧𝐬

 𝐓𝐨𝐝𝐚𝐲'𝐬 𝐊𝐍𝐎𝐖𝐋𝐄𝐃𝐆𝐄 𝐒𝐡𝐚𝐫𝐞

👋💡 𝐓𝐲𝐩𝐞𝐬 𝐨𝐟 𝐀𝐜𝐫𝐲𝐥𝐢𝐜 𝐑𝐞𝐬𝐢𝐧𝐬⚙️

Acrylic resins are generally divided into two main categories, and based on these categories any resin type can be classified: Thermoplastic and Thermosetting.

To prepare a resin from either category, the polymer must be converted into a solution, meaning that the polymer is dissolved in an organic solvent. The monomers—such as MMA, BA, or EA—are polymerized and then dissolved in an organic solvent to form the solution.

🥇Thermoplastic Solution Acrylics (TPAs)

This type is a copolymer, made from different monomers that build long polymer chains, which gives it a high molecular weight.

This type does not use crosslinkers 🛠️to form a network structure, because the film forms simply through the entanglement of the long polymer chains⛓️.

TPAs cure at ambient temperature without the need for any crosslinkers.

Because of their high molecular weight, they form a film by solvent evaporation.

The glass transition temperature (Tg)🕯️ plays an important role in this system.

Generally, the Tg of these resins is above 20°C and below 80°C.

If a hard and strong film is required, the resin is usually based on MMA or Styrene, and has a high molecular weight.

If a film with high flexibility is needed, the resin is usually based on EA or BA.

🥈Thermosetting Solution Acrylic.

This type contains different functional groups that enable the formation of a crosslinked network. It always requires a curing agent to produce a hard, infusible film after curing.

Functional monomers are incorporated into the polymer, such as:

Hydroxyethyl acrylate for OH groups

Methacrylic acid for COOH groups

Glycidyl methacrylate for epoxy groups

These functional groups are capable of forming a rigid crosslinked network through crosslinking reactions between them and the curing agent.

This type of resin generally has a high Tg🕯️ because the polymer chains are held tightly together in a strong network.

Even though the molecular weight may be relatively low due to shorter chain length, the functional groups located on the chain ends can form a strong, rigid network through crosslinking.

☂️Under these two categories, many types of acrylic resins can be classified, such as:Waterborne acrylic resin

Acrylic resin for high-solids coatings

Acrylic Resin for Radiation-Curable Coatings

Let’s talk about a special type of Thermosetting Solution Acrylic Resin, which is:

Acrylic Resin for Radiation-Curable Coatings

This type cures through exposure to UV light or an electron beam, and we will explain how this happens.

This resin is referred to as an oligomer because it has short polymer chains and relies heavily on functional groups and a curing mechanism.

To be able to form a film from this system, we must use something called a photoinitiator, which generates the free radicals required to initiate the crosslinking process.

source : Hussein Abd El-Rhman