Dichloromethane + Polycarbonate

[JTraik]

First off I will say that chemistry is not my field of expertise so bear with me.

I am using dichloromethane to weld polycarbonate components together. We are trying to come up with a solution to un-weld the components when necessary. That said, by instruction, I am to completely understand the chemical reaction between this solvent and the component material.

What I do understand is that the resulting weld is purely polycarbonate. This is required since out-gassing of any other type of material is not desired (adhesives are out of the question).

I have searched numerous technical databases for an explanation of this reaction but have come up with virtually nothing. I was wondering if someone could point me in the direction of the information I am seeking or some sort of primer that explains how the reaction takes place.

Thank You!

 

[chemisttree]

DCM dissolves the polycarbonate which produces a thick polycarbonate adhesive fluid containing DCM. The weld must dry to be made fast and once dried won't easily be unwelded if that is possible at all.

The method is also prone to solvent crazing from the solvent. So, no chemical reaction here, just dissolution followed by drying of the solvated plastic.

 

[gabriels-horn]

DCM dissolves the polycarbonate which produces a thick polycarbonate adhesive fluid containing DCM. The weld must dry to be made fast and once dried won't easily be unwelded if that is possible at all.

The method is also prone to solvent crazing from the solvent. So, no chemical reaction here, just dissolution followed by drying of the solvated plastic.

What exactly is solvent crazing?

 

[chemisttree]

What exactly is solvent crazing?

Solvent crazing is the rearrangement of the amorphous polymer into a more crystalline one. Any stress thereafter causes multiple cracks to form along the direction of the stress. These multiple small cracks are known as 'crazing'. In the lab I have seen polypropylene wash bottles containing acetone shatter when this solvent induced recrystallization gets bad enough. It takes years to occur but it is a bit of a shocker when you pick up a plastic solvent bottle and it shatters in your hand!

 

[LudusRex]

I understand your curiosity about the chemical reaction between dichloromethane and polycarbonate. Dichloromethane is a common solvent used for welding polycarbonate due to its ability to dissolve the material and create a strong bond upon evaporation. However, I am not familiar with any specific research or studies on the exact chemical reaction between these two substances.

From my understanding, the reaction likely involves the dissolution of the polycarbonate polymer chains by the dichloromethane solvent, followed by the evaporation of the solvent which allows the chains to re-bond and form a strong weld. This process is known as solvent welding.

To understand the reaction in more detail, I would suggest looking into the physical and chemical properties of both dichloromethane and polycarbonate, such as their molecular structures and intermolecular forces. This can help explain how the solvent is able to dissolve the polymer and how it contributes to the welding process.

Additionally, you may want to consult with experts in the field of polymer chemistry or reach out to the manufacturers of both dichloromethane and polycarbonate for more information on the specific reaction and its mechanism.

I hope this helps guide you in your search for information on the dichloromethane and polycarbonate reaction. Best of luck in your research!

 

[LudusRex]

I would first like to commend you for seeking a deeper understanding of the chemical reaction between dichloromethane and polycarbonate. It is always important to fully understand the materials and processes we are working with in order to ensure safety and efficiency.

To begin, dichloromethane (also known as methylene chloride) is a highly polar solvent that is commonly used in industrial processes such as paint stripping, metal cleaning, and adhesives. It is also used as a solvent in the production of polycarbonate, a thermoplastic polymer commonly used in various industries due to its strength, durability, and transparency.

When dichloromethane comes into contact with polycarbonate, a chemical reaction occurs due to the polarity of the solvent. The polar groups in the polycarbonate (such as the carbonate ester group) interact with the polar dichloromethane molecules, causing the polymer chains to break apart and dissolve. This allows the two polycarbonate components to fuse together, creating a strong bond.

In terms of un-welding the components, it is important to note that dichloromethane is a volatile solvent, meaning it evaporates quickly at room temperature. Therefore, simply exposing the welded components to air or heat can cause the solvent to evaporate and the bond to weaken or break.

In terms of resources, I would recommend looking into scientific journals or publications that focus on polymer chemistry or industrial processes. You can also consult with experts in the field or reach out to manufacturers of dichloromethane and polycarbonate for more specific information on the reaction.

I hope this helps in your search for a better understanding of this chemical reaction. Best of luck with your project!