White Crystals Dimethylolbutanoic Acid or Dmba

• Customization: Available
• CAS No.: 10097-02-6
• Formula: C6h12o4
• Model NO.: 99% min
• Appearance: Powder
• Usage: Hydrophilic Chain Extender Agents
• Color: White
• Melting Point: 112ºC
• Transport Package: 25kg/Bag
• Specification: purity ≥ 99%
• Trademark: CHX
• Origin: China
• HS Code: 2918190090
• Production Capacity: 1500 Ton Per Year

Product Description

Specification

Identification:
Name:Dimethylolbutanoic acid
         [2,2-Bis(hydroxymethyl)butyric Acid]
           DMBA
                                        
Molecular Formula: C6H12O4
Molecular Weight: 148.16
CAS Number:10097-02-6
Specification:

Index	Standard
Appearance	White crystals
Purity %	≥99
Water %	≤0.3
Melting Point ºC	108-117
Ash %	≤0.03
Residue Formaldehyde %	≤0.03
Acid Value (mgKOH/g)	374.7-378.2
Hydroxyl Value (mgKOH/g)	728-782
Fe^3+  (PPM)	≤5
Na^+   (PPM)	≤150
K^+   (PPM)	≤10
SO4²¯ (PPM)	≤10
Acetone-Et3N Solube Experiment	Transparent

Application:
There are two main types of hydrophilic chain extenders for dimethylol carboxylic acid used in DMPA and DMBA, of which DMPA is the most commonly used one. Although it has many advantages, there are still many disadvantages, mainly its own melting point is high (180 °C-185 °C), it is difficult to heat and melt, which requires the addition of organic solvents such as N-methylpyrrolidone (NMP), N.N-dimethylamide (DMF), acetone, etc., and NMP has a high boiling point, which is difficult to remove after preparing APU. Moreover, DMPA has a small solubility in acetone, and a large amount of acetone needs to be added in the synthesis process, which wastes energy and brings potential safety hazards in the deketization process. Therefore, the use of DMPA not only consumes high energy in production, but also easily causes organic residues in the product. Due to its special molecular structure, DMBA does not need to consume a little solvent in the synthesis process, which not only shortens the reaction time, reduces energy consumption, but also saves energy. Compared with DMPA, DMBA has the following obvious advantages:

1. . DMBA has better solubility in organic solvents, and Table 1 shows the solubility data of DMBA and DMPA in different solvents at different temperatures.
       Table 1: Solubility data of DMBA and DMPA in different solvents at different temperatures

Item	Temperature ºC	Acetone		Methyl ethyl ketone		Methyl isobutyl ketone
		DMBA	DMPA	DMBA	DMPA	DMBA	DMPA
1	20	15	1	7	0.4	2	0.1
2	40	44	2	14	0.8	7	0.5

Solubility: unit g/100g solvent.DMBA has a solubility of 48% in water and a DMPA of 12%.and the melting point of DMBA is low, it is 108°C~115°C
Due to its excellent solubility and low melting point, DMBA does not require solvent or adds less solvent in the synthesis of waterborne polyurethane emulsions.
    Using DMBA as a hydrophilic chain extender, the whole reaction process can be basically completed in 6 hours without solvent, making the product environmentally friendly, and does not need to be desolubilized and avoid waste.
    In the process of synthesizing waterborne polyurethane with DMBA, the whole reaction process can be completed without adding a little solvent, and the reaction results are attached to the formula design.

1. . High reaction rate, fast reaction speed and low reaction temperature.
       Synthetic polyurethane prepolymers have a short reaction time, typically only 50-60 minutes, while DMPA takes 150-180 minutes. This is because there is one more methylene group in the DMBA structure than DMPA, which increases the distance between the carboxyl group and the methylene group, and reduces the steric hindrance between the carboxyl group and the isocyanate, so that the reaction rate increases.
2.  For waterborne polyurethane emulsions, its particle size is finer and narrower, the film performance is excellent, and the gloss is high.
       The tensile strength and elongation at break of DMBA polyurethane emulsion are higher than those of DMPA polyurethane because:
       First, the molecular structure of DMBA, the huge side chain - CH2COO- hinders the aggregation of the hard segment of polyurethane, and the degree of hard segment stacking is poor, so that the hard segment itself has a high solubility in the soft segment matrix, and the hard segment decreases in the micro area of the hard segment, these factors will lead to a decrease in modulus, but low modulus will lead to a larger elongation at break, which in turn will cause further stress crystallization in the soft segment, resulting in a higher tensile strength.
       The second is that DMBA has a lower melting point than DMPA, and DMBA is easy to melt in polyols, so DMBA can react completely according to the formula in the same time, and because only a part of DMPA is dissolved and reacted, DMBA has a larger molecular weight and superior mechanical properties than DMPA. The reason why DMBA has a higher gloss than DMPA may be due to the better hydrophilicity of DMBA, resulting in a smaller particle size and more uniform particles in the emulsion.

In summary, dimethylol butyric acid has incomparable advantages over dimethylolpropionic acid, and can be regarded as the hydrophilic compound with the best performance.