Should I dilute sulfonic acid before neutralizing it with Sodium hydroxide ?

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Comments

  • agagag said:
    I've got another question. I made neutralisation and after night I get product with pH 8. But my sample delaminate...On the top my pH is 8, and on the bottom pH is 12. Should I change the quantity of NaOH...?
    What's LABSA concentration?
    Some low grade LABSA have trouble getting past 15%.

    Also, you can try neutralizing it with Sodium carbonate (Soda ash) instead of NaOH to see if it works.
  • Chemist77Chemist77 Member, PCF student
    I add my alkali first to water, then LABSA. Can always adjust pH slowly at the end. 
  • My LABSA is 95% and I dilute it into 30%. Than I am adding 30% NaOH and I have delaminate salt. Tomorrow I will mix it as @Chemist77 wrote

  • Is that 30% total LABSA in your finished formulation?
    If so, this is too high a concentration.

    Also, 30% LABSA doesn't need 30% total NaOH to neutralize
    search for LABSA and NaOH molecular weights, to get the relative proportions to each other.
  • Thank you @Gunther. Yes, now I am searching for the best proportion to get neutralized product. I am also checking how long my neutralitzaion will take.
  • you should dilute LABSA before neutralize by NaOH (30%), for get pH 8 , use NaOH then adjust by TEA
  • Thank you guys for educating us.

    What percentage of NaOH & LABSA is required too get a clear & transparent mixture with relaive thickness/viscosity. What percentage of water should l use to dissolve the NaOH.

    Do l need to dilute the LABSA, if Yes, what water percentage is required and what is sequence of mixing the ingredients.

  • Chemist77Chemist77 Member, PCF student
    @imasoat anything upto 20% should keep you good plus if you have other surfactants. I use around 12% plus few other surfactants and the results are pretty good.
  • ...I think my LABSA is not so pure as I thought…@Chemist77 do you know how long did you mix LABSA with NaOH to get pH8?
  • Chemist77Chemist77 Member, PCF student
    Mixing period will not decide the pH, your acid to base ratio will. 
  • AzizAziz Member
    edited January 25
    shaujaat said: 
    aaaaaa There is no problem with your material..... It happened to me as well with the same material I uses, what I think what happened was I didnt gave time to each liquid to dissolve completely and poured whole of it at once. It is better for your to divide the water that you are going to use in the process in to two and dilute the sulfuic in the water and then pour slowly the NAOH to neutralize it. don't mix it with other materials until it cools down, that's my experience 

    Perhaps this is one of the most valuable comments of this thread . I faced same problem at first and then over come it by following the Rule , 
    ' Never put your second ingredients until your first one is completely dissolved ' . 
    Dissolve NaOH in adequate of water , then pour LABSA slowly with stirring over a 15 to 20 minutes of time and continue stirring until completely dissolve and get a transparent solution . 
    Hope you will overcome this problem . 
  • For the same amount of LABSA (preferably <20% in the final formulation)
    try neutralizing it with both NaOH and Sodium carbonate (in proper proportions to each other, so Google LABSA, NaOH and Sodium carbonate molecular weights)

    I got a feeling that the strongly alkaline NaOH degrades LABSA, unlike the milder carbonate.
  • GuntherGunther Member
    This study states neutralized LABSA cloud points as:

    https://ejchem.journals.ekb.eg/article_7631_aed50d75c833b783095ca669b368d51a.pdf

    This might explain why I had trouble getting clear formulations beyond 15% neutralized LABSA.
    While I was able to get some clear 15-20% sulfonate formulations at room temperature, I'll see if they cloud at low temps.

    Also, the study shows that cloud point is highly dependent on salt content.
  • RedPillRedPill Member
    @Gunther Did you overcome this isse? I am also facing the same problem.
    Mixed 200ml LABSA with 200 ml water.
    Ph balanced approx 7 with 50% caustic solution.
    After 8 hours normally we can expect a transparent liquid. But in this case the solution is solid thick white paste.
  • GuntherGunther Member
    RedPill said:
    @Gunther Did you overcome this isse? I am also facing the same problem.
    Mixed 200ml LABSA with 200 ml water.
    Ph balanced approx 7 with 50% caustic solution.
    After 8 hours normally we can expect a transparent liquid. But in this case the solution is solid thick white paste.
    Some things that help avoiding/managing this:
    1 Predilute LABSA with water. Add a water volume/weight at least equal, preferably twice LABSA weight.

    2 Predilute solid NaOH in water

    3 Always add NaOH solution slowly to the LABSA solution, and never the other way around. It looks like an alkaline pH causes the problem, while an acidic one lessens or avoids it.

    4 Don't add any further NaOH beyond pH 8.

    5 You can try slowly neutralizing it with a 20% Sodium carbonate solution. While it generates a lot of bubbles and you must wait for them to dissipate, it's harder to overshoot pH into the alkaline range with Na2CO3 than with NaOH.

    6 Some manufacturers LABSA cloud right when pH gets past 7, despite using Sodium carbonate instead of NaOH. Switching LABSA suppliers is a must then.

    7 Don't add any salt to it, it just rises cloud point.
    If you need a thicker product, add more neutralized LABSA, SLES, CAPB or both.
  • RedPillRedPill Member
    @Gunther Thank you for your very detailed procedures. 
  • AzizAziz Member
    Gunther said:
    For the same amount of LABSA (preferably <20% in the final formulation)
    try neutralizing it with both NaOH and Sodium carbonate (in proper proportions to each other, so Google LABSA, NaOH and Sodium carbonate molecular weights)

    I got a feeling that the strongly alkaline NaOH degrades LABSA, unlike the milder carbonate.
    My dish wash is transparent,  thick and stable at 4°C but foam is not so well.  
    How to achieve sufficient foam in final product ? 
    Which of ingredients degrade foam ? 
  • GuntherGunther Member
    Aziz said:
    Gunther said:
    For the same amount of LABSA (preferably <20% in the final formulation)
    try neutralizing it with both NaOH and Sodium carbonate (in proper proportions to each other, so Google LABSA, NaOH and Sodium carbonate molecular weights)

    I got a feeling that the strongly alkaline NaOH degrades LABSA, unlike the milder carbonate.
    My dish wash is transparent,  thick and stable at 4°C but foam is not so well.  
    How to achieve sufficient foam in final product ? 
    Which of ingredients degrade foam ? 
    What's the formula like?
  • AzizAziz Member
    @Gunther

    LABSA  8%
    NaOH To pH 8.5
    EDTA .2%
    Na citrate .5%
    SLES    4%
    SLS  1%
    TSP  1%
    CDEA   3%
    CAPB ( 30%)  4.5 %
    NACL 1%
    MPS .05%
    Perfume. 2%
    Colour 
    Water to 100 



  • RedPillRedPill Member
    @Gunther Can we determine LABSA quality with its colour? I have seen Light transparent yellowish to Dark chocolate coloured LABSA.
    Can we neutralize LABSA with Pottasium Hydroxide? (KOH) Is there any difference using than Sodium Hydroxide?
    I have encountered seperation when adding TKPP with neutralized LABSA. Do you have any knowledge about this issue?

  • GuntherGunther Member
    Aziz said:
    @Gunther

    LABSA  8%
    NaOH To pH 8.5
    EDTA .2%
    Na citrate .5%
    SLES    4%
    SLS  1%
    TSP  1%
    CDEA   3%
    CAPB ( 30%)  4.5 %
    NACL 1%
    MPS .05%
    Perfume. 2%
    Colour 
    Water to 100 



    Add more SLES, but get rid of SLS
    You can also add more LABSA with NaOH as required.
    Some Ethoxylated alcohol helps with foam too.

    Get rid of TSP as phosphates cause eutrophication of rivers and lakes and don't add anything that LABSA or SLES doesn't.

    Did you cloud test this formulation?
    "Cold weather Cloud Testing" can be as simple as putting the formulation in the fridge (without freezing) and see if it clouds on lower temps.
    Lots and lots of beginner LABSA formulations cloud at low temps.

    Get rid of salt and Na-citrate as they just rise cloud points.

    RedPill said:
    @Gunther Can we determine LABSA quality with its colour? I have seen Light transparent yellowish to Dark chocolate coloured LABSA.
    Can we neutralize LABSA with Pottasium Hydroxide? (KOH) Is there any difference using than Sodium Hydroxide?
    I have encountered seperation when adding TKPP with neutralized LABSA. Do you have any knowledge about this issue?

    All 95%+ LABSAs I have seen are dark brown.
    If it's yellow then it's either preneutralized, or diluted.

    You can use KOH as it's supposed to help rise cloud point temps.

    I don't like phosphates.
    They cause eutrophication of lakes and rivers and don't add anything useful to the formula that greener ingredients like LABSA, SLES or ethoxylated alcohols don't.
  • AzizAziz Member
    Gunther said:
    Aziz said:
    @Gunther

    LABSA  8%
    NaOH To pH 8.5
    EDTA .2%
    Na citrate .5%
    SLES    4%
    SLS  1%
    TSP  1%
    CDEA   3%
    CAPB ( 30%)  4.5 %
    NACL 1%
    MPS .05%
    Perfume. 2%
    Colour 
    Water to 100 



    Add more SLES, but get rid of SLS
    You can also add more LABSA with NaOH as required.
    Some Ethoxylated alcohol helps with foam too.

    Get rid of TSP as phosphates cause eutrophication of rivers and lakes and don't add anything that LABSA or SLES doesn't.

    Did you cloud test this formulation?
    "Cold weather Cloud Testing" can be as simple as putting the formulation in the fridge (without freezing) and see if it clouds on lower temps.
    Lots and lots of beginner LABSA formulations cloud at low temps.

    Get rid of salt and Na-citrate as they just rise cloud points.

    RedPill said:
    @Gunther Can we determine LABSA quality with its colour? I have seen Light transparent yellowish to Dark chocolate coloured LABSA.
    Can we neutralize LABSA with Pottasium Hydroxide? (KOH) Is there any difference using than Sodium Hydroxide?
    I have encountered seperation when adding TKPP with neutralized LABSA. Do you have any knowledge about this issue?

    All 95%+ LABSAs I have seen are dark brown.
    If it's yellow then it's either preneutralized, or diluted.

    You can use KOH as it's supposed to help rise cloud point temps.

    I don't like phosphates.
    They cause eutrophication of lakes and rivers and don't add anything useful to the formula that greener ingredients like LABSA, SLES or ethoxylated alcohols don't.
    Yes I did the cloud test , without TSP and citrate it is stable at 4°C . And if Gsalt (Na₂SO₄ ) is used , cloud point increases .
    I already deduct TSP and citrate . I added SLS for foaming . Then I tried with 1% AOS to  achieve foam . It slightly increses foam .

    I have two quality of LABSA , one is blackish and doesn't give a clear and consistent dish wash and it was lower priced . A reddish one is fine , no issue with consistency , but I couldn't achieve optimum foaming performance.  My LABSA (96%) is not preneutralized , I neutraled it with NaOH . I know amine oxides are good for foaming but it is not available . 
    Oh another issue is some of the batches changing colour over time . 
  • GuntherGunther Member
    @Aziz may I ask what's the intended application?

    If it's for manual dishwashing
    then a shampoo-like formula will work fine with much less irritation and cloudiness problems than LABSA.
    SLES as the main surfactant, followed by a smaller amount of SLS (or neutralized LABSA), CAPB and even CDEA.

    If it's for liquid laundry or institutional dishwashing
    Then LABSA 10-12%, SLES 4-8% and a small amount of CAPB (but not salt) will work fine.

    Try to get the Certificate of Analysis from the suppliers to check their purities and concentration.
    LABSA batches shouldn't change color, and all those I've seen are dark brown, albeit with slighltly different hues.
  • GuntherGunther Member
    Maybe it is low quality LABSA is ladden with free sulfuric acid:

    Linear alkyl benzene sulphonate obtained by sulphonation of LAB with sulphur trioxide gas contains minimum free sulphuric acid and is preferred to LABS obtained from oleum sulphonation that has a higher proportion of free sulphuric acid. Free sulphuric acid present precipitates as sodium sulphate increasing the inorganic content of the product and thereby reducing the
  • AzizAziz Member
    Gunther said:
    @Aziz may I ask what's the intended application?

    If it's for manual dishwashing
    then a shampoo-like formula will work fine with much less irritation and cloudiness problems than LABSA.
    SLES as the main surfactant, followed by a smaller amount of SLS (or neutralized LABSA), CAPB and even CDEA.

    If it's for liquid laundry or institutional dishwashing
    Then LABSA 10-12%, SLES 4-8% and a small amount of CAPB (but not salt) will work fine.

    Try to get the Certificate of Analysis from the suppliers to check their purities and concentration.
    LABSA batches shouldn't change color, and all those I've seen are dark brown, albeit with slighltly different hues.

    @Gunther It is for kitchen dish washing . Customers want  ' Fairy ' like performance from it . Main purpose is to remove oil , fat , carbohydrates and dirt from dishes , plates etc. Now I am facing foaming performance . 
  • 12% LABSA, 6% active SLES works fine (intended as a liquid laundry detergent)
    it doesn't cloud in the fridge at all, but you must add both some CAPB and NaCl ( <0.25% ) to thicken it.

    I tried the same formula neutralizing it with KOH instead of NaOH and it became real cloudy. Cloudy even before all the LABSA was neutralized.
    That was unexpected, as Potassium salts usually have better solubility than their Sodium counterparts.

    Some 2.5% dipropylene glycol made it clear again, but it sharply reduces viscosity.
  • @Gunther
    https://ejchem.journals.ekb.eg/article_7631_aed50d75c833b783095ca669b368d51a.pdf

    I reviewed the above link you provided. Have you tried testing that formulation? Right now I have the below formula. Is it any good?

    SLES5.00%
    LABS6.50%
    CDEA1.00%
    DMDM0.05%
    Colorant0.01%
    Scent0.10%
    Caustic1.70%
    WaterBalance

    I'm thinking of adding AOS powder to the formulation you provided because there are studies that 80:20 ratio of LABSA and AOS results to high foaming. What do you think?
  • ketchitoketchito Member
    edited September 4
    Among the common anionic surfactants, LABS is the most hydrophobic (due to the aromatic ring). Addition of electrolytes (like NaCl) makes it even more hydrophobic and prone to precipitation, since Na+ ions neutralize the negative charge of SO3-, which is the water soluble part of the molecule; that's why the more NaCl is added, the lower the cloud point. 

    One thing to work around this problem (without using an hydrotrope which impair foam and performance) is to neutralize it with TEA, since TEA-alkylbenzene sulfonate is more soluble than its sodium counterpart. You can use only TEA (more expensive), or a mixture of TEA and NaOH. Another way is to change the ratio LABS/LESS (a good starting point is 8:2, and to improve solubility, you can increase LESS and reduce LABS). 

    Also, keep in mind that some surfactants have hidden amounts of NaCl, like Betaines and Amine oxides. Interestingly, Lauramidopropylamine oxide allows lower cloud points than the other amine oxides, while producing more foam and even helps build more viscosity. Besides amine oxides, olefin sulfonates and sultaines also help achieve more foam at low doses. There are also some polymers which are very useful, such as Sokalan HP20 and Supracare 801.

    pH also plays a major part, since pH lower than 5 make Betaines and Amine oxides behave as cationics, clouding the product right away; for better clarity, a pH above 8 is advised.
  • ketchito said:
    Among the common anionic surfactants, LABS is the most hydrophobic (due to the aromatic ring). Addition of electrolytes (like NaCl) makes it even more hydrophobic and prone to precipitation, since Na+ ions neutralize the negative charge of SO3-, which is the water soluble part of the molecule; that's why the more NaCl is added, the lower the cloud point. 

    One thing to work around this problem (without using an hydrotrope which impair foam and performance) is to neutralize it with TEA, since TEA-alkylbenzene sulfonate is more soluble than its sodium counterpart. You can use only TEA (more expensive), or a mixture of TEA and NaOH. Another way is to change the ratio LABS/LESS (a good starting point is 8:2, and to improve solubility, you can increase LESS and reduce LABS). 

    Also, keep in mind that some surfactants have hidden amounts of NaCl, like Betaines and Amine oxides. Interestingly, Lauramidopropylamine oxide allows lower cloud points than the other amine oxides, while producing more foam and even helps build more viscosity. Besides amine oxides, olefin sulfonates and sultaines also help achieve more foam at low doses. There are also some polymers which are very useful, such as Sokalan HP20 and Supracare 801.

    pH also plays a major part, since pH lower than 5 make Betaines and Amine oxides behave as cationics, clouding the product right away; for better clarity, a pH above 8 is advised.
    Very very interesting.
    Thank you for posting that.

    Do you have some references or interesting reads on that?
  • @ketchito
    What is LESS? Was that a typo? Are you referring to SLES? Thanks for the info.
  • ketchito said:
    Among the common anionic surfactants, LABS is the most hydrophobic (due to the aromatic ring). Addition of electrolytes (like NaCl) makes it even more hydrophobic and prone to precipitation, since Na+ ions neutralize the negative charge of SO3-, which is the water soluble part of the molecule; that's why the more NaCl is added, the lower the cloud point. 

    One thing to work around this problem (without using an hydrotrope which impair foam and performance) is to neutralize it with TEA, since TEA-alkylbenzene sulfonate is more soluble than its sodium counterpart. You can use only TEA (more expensive), or a mixture of TEA and NaOH. Another way is to change the ratio LABS/LESS (a good starting point is 8:2, and to improve solubility, you can increase LESS and reduce LABS). 

    Also, keep in mind that some surfactants have hidden amounts of NaCl, like Betaines and Amine oxides. Interestingly, Lauramidopropylamine oxide allows lower cloud points than the other amine oxides, while producing more foam and even helps build more viscosity. Besides amine oxides, olefin sulfonates and sultaines also help achieve more foam at low doses. There are also some polymers which are very useful, such as Sokalan HP20 and Supracare 801.

    pH also plays a major part, since pH lower than 5 make Betaines and Amine oxides behave as cationics, clouding the product right away; for better clarity, a pH above 8 is advised.
    You're right!
    I just tried 15 and 20% LABSA neutralized with TEA and they was clear (if neutralized with Sodium hydroxide they would have been cloudy)

    They were clear even with 0.5% salt, albeit -TEA viscosities were lower than those for -Sodium.
    While I still need to conduct a salt curve and cost analysis, but this quick experiment shows you were totally right.
  • ketchitoketchito Member
    edited September 26
    Gunther said:
    ketchito said:
    Among the common anionic surfactants, LABS is the most hydrophobic (due to the aromatic ring). Addition of electrolytes (like NaCl) makes it even more hydrophobic and prone to precipitation, since Na+ ions neutralize the negative charge of SO3-, which is the water soluble part of the molecule; that's why the more NaCl is added, the lower the cloud point. 

    One thing to work around this problem (without using an hydrotrope which impair foam and performance) is to neutralize it with TEA, since TEA-alkylbenzene sulfonate is more soluble than its sodium counterpart. You can use only TEA (more expensive), or a mixture of TEA and NaOH. Another way is to change the ratio LABS/LESS (a good starting point is 8:2, and to improve solubility, you can increase LESS and reduce LABS). 

    Also, keep in mind that some surfactants have hidden amounts of NaCl, like Betaines and Amine oxides. Interestingly, Lauramidopropylamine oxide allows lower cloud points than the other amine oxides, while producing more foam and even helps build more viscosity. Besides amine oxides, olefin sulfonates and sultaines also help achieve more foam at low doses. There are also some polymers which are very useful, such as Sokalan HP20 and Supracare 801.

    pH also plays a major part, since pH lower than 5 make Betaines and Amine oxides behave as cationics, clouding the product right away; for better clarity, a pH above 8 is advised.
    Very very interesting.
    Thank you for posting that.

    Do you have some references or interesting reads on that?
    My pleasure. There are some great books where you can find very nice info, like: "Anionic surfactants: organic chemistry", "Liquid detergents" and "Handbook of detergents", all from CRC Press. 
  • I'm glad it helped!
  • mecchem said:
    @ketchito
    What is LESS? Was that a typo? Are you referring to SLES? Thanks for the info.
    Yes, I meant SLES (the spanish sneaked in, sorry about that). 
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