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Precautions Before Use

Connecting the World Through Top-Quality and Eco-Friendly Technology 


G Polytec 


Sustainable, high-performance custom water-based polyurethane resin 

G Polytec 


We develop customized water-based polyurethane resins
that balance high performance with environmental responsibility.  

Localized Reaction

A localized reaction refers to a reaction that progresses unevenly in specific areas. Instead of the urethane reaction proceeding according to the designed molecular structure, the reaction proceeds locally, which can prevent the intended properties from being achieved. It can also make dispersion difficult, significantly reducing the resin's storage stability.

Localized Reaction Results

Potential issues caused by a localized reaction include the following:

  • Unstable dispersion caused by a mixture of hydrophobic and hydrophilic characteristics (oil-water mixing issue).

    (It disperses when water is added during the dispersion process, but when water is not added, it returns to a cream-like form.)

  • Large particle size in the dispersed water-based polyurethane dispersion (PUD), with an excessively broad particle size distribution.

  • Significantly reduced storage stability due to poor dispersion, causing phase separation to occur easily.

  • Very coarse particle size (does not flow down smoothly on a glass surface).

Causes of Localized Reactions

Description

Solutions
Lack of Compatibility
Limited miscibility between raw materials
  • Add a high-solvency solvent to fully dissolve the materials before starting the reaction 
  • Carry out a pre-reaction for raw materials with low compatibility
  • Set the reaction time longer than the standard reaction time (1.2x)
Differences in Reactivity
Differences in reactivity between raw materials
  • Run a pre-reaction focusing on raw materials with slower reactivity 
  • Extend the reaction time as needed
  •  Increase the reaction temperature to drive the reaction forward (watch for side reactions). 
  • Promote the reaction through stepwise catalyst addition. 
Catalyst Effect

Non-uniform reaction caused by the timing of catalyst addition

  • In the early stage, run the reaction without a catalyst so it proceeds slowly at first
  • For highly reactive raw materials, adjust the amount and timing of catalyst addition appropriately
Troubleshooting Tips

  • When formulating water-based polyurethane dispersion (PUD), be sure to check raw material miscibility.
  • When formulating the product, always consider how each raw material reacts with each isocyanate.
  • If a solvent can be used at the initial stage, add a sufficient amount to improve miscibility.

Side Reactions 

Side reactions are reactions that frequently occur during polyurethane synthesis. They refer to unexpected reactions caused by factors such as raw material contamination or excessive reaction temperature and time. Side reactions can significantly increase the viscosity of the synthesized material and may sometimes cause crosslinking. They can also generate sludge in the reaction mixture, making it difficult for the reaction to proceed.

Side Reaction Results

Potential issues caused by side reactions include the following:

  • The viscosity of the synthesized material becomes very high, increasing the amount of solvent required for dispersion.
  • A dispersed water-based polyurethane dispersion (PUD) is more likely to have a smaller particle size.
  • As the molecular weight increases, the physical properties become higher than intended.
  • Sludge forms during synthesis, preventing the reaction from proceeding smoothly.
Causes of Side Reactions

Description

Solutions
Catalyst Addition
Overreaction due to the catalyst
  • Delay the timing of catalyst addition. 
  • Add the catalyst in small portions using a diluted catalyst.
High Reaction Temperature
Side reaction due to high reaction temperature
  • Reduce the time spent at high temperature. 
  • Start the reaction with the less reactive raw materials first.
Raw Material Contamination

Side reaction due to moisture and molecular weight variation

  • Thoroughly control moisture.
  • Thoroughly control molecular weight distribution.
Troubleshooting Tip

  • When formulating water-based polyurethane dispersion (PUD), be sure to check raw material miscibility.
  • When formulating the product, always consider how each raw material reacts with each isocyanate.
  • If a solvent can be used at the initial stage, add a sufficient amount to improve miscibility.

Compatibility

Compatibility refers to the miscibility between raw materials. When raw materials mix easily, the reaction sequence is determined by factors such as each raw material's reactivity and molecular weight. However, when raw materials lack compatibility, the reaction tends to be non-uniform, which can lead to localized reactions. For this reason, compatibility is one of the first factors to consider during product development. It is also a key factor in ensuring production stability and reproducibility for the finished product. Compatibility is a fundamental requirement for product development and production.

GS-7Q Compatibility       

◎ For ester polyols, the GS-7Q ratio is blended based on a general-purpose adhesive standard (footwear). 

(GS-7Q: 4.0 wt%, ester polyol: 85 wt%).

Type : Adipic Acid + 1,4 BD

Original

M.W = 1,000

M.W = 2,000

◎ For ether polyols, the GS-7Q ratio is blended based on a general-purpose coating standard.

(GS-7Q : 4.5 wt% , ether polyols : 77wrt %).

PolyPropylene Glycol

Original

M.W = 1,000

M.W = 2,000

PTMEG

M.W = 1,000

Results of Poor Compatibility

Reactions using raw materials with poor compatibility can lead to the following issues:


  • Inaccurate analysis data due to lack of reproducibility - Experimental data becomes unreliable because different localized reactions occur each time. 

  • Unpredictable localized reactions - Because unintended reactions proceed, reproducibility cannot be ensured, and the results are difficult to use as experimental data.

  • Presence of unpredictable unreacted materials - Slow-reacting raw materials may remain without participating in the reaction until they are dispersed.

  • Longer reaction time than expected - Extended reaction time can lead to unexpected reactions.

Causes of Compatibility Issues

Description

Solutions
Catalyst Addition
Overreaction due to the catalyst
  • Add a high-solvency solvent to fully dissolve the materials before starting the reaction. 
  • Carry out a pre-reaction for raw materials with low compatibility. 
  • Set the reaction time longer than the standard reaction time (1.2x). 
High Reaction Temperature
Side reaction due to high reaction temperature
  • Run a pre-reaction focusing on raw materials with slower reactivity. 
  • Extend the reaction time as needed. 
  • Increase the reaction temperature to drive the reaction forward (watch for side reactions). 
  • Promote the reaction through stepwise catalyst addition. 
Raw Material Contamination

Side reaction due to moisture and molecular weight variation

  • In the early stage, run the reaction without a catalyst so it proceeds slowly at first.
  • For highly reactive raw materials, adjust the amount and timing of catalyst addition appropriately.
Troubleshooting  Tip

  • When formulating water-based polyurethane dispersion (PUD), be sure to check raw material miscibility.
  • When formulating the product, always consider how each raw material reacts with each isocyanate.
  • If a solvent can be used at the initial stage, add a sufficient amount to improve miscibility.

Email   g.polytec@gmail.com 

Phone  82) +52. 267. 0168 

CEO: Richard J. Park 

Address: 39-5, Goyeongongdan 1-gil, Ungchon-myeon, Ulju-gun, Ulsan, Korea 

Fax: 82) 52-268-0168

Email: jcchoicn@gmail.com

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