Introduction

Nonionic surfactants are increasingly becoming more important since they are soluble in water and many organic solvents, and they are also compatible with many other types of surfactants. The most common nonionic surfactants are those based on ethylene oxide, referred to as ethoxylated surfactants [1–4]. Poly (oxyethylene) alkyl ethers are nonionic surfactants having general chemical structure H(CH2) n (OCH2CH2) m OH, which is purely indicated by C n E m , where m refers to the number of ethylene oxide units in the molecule, and n refers to the number of carbon atoms in the hydrocarbon chain [5].

Fatty alcohol ethoxylates (FAEs), commonly referred to as ethoxylated fatty alcohols, monoalkyl poly(ethylene oxide) glycol ethers, alkyl polyoxyethylene glycol, etc., are the most widely used nonionic surfactants in the industry due to their low toxicity [6]. The fatty alcohols are derived either from petrochemical raw materials or from natural fats and oils. Transesterification with methanol or esterification of different fatty acids, resulting from the hydrolysis of natural triglycerides, followed by hydrogenation of the methyl ester results in straight-chain unsaturated or saturated alcohols in the alkyl range from C 8 to C 18 . Synthetic fatty alcohols can be prepared from Ziegler or Oxo processes [7]. The Ziegler process results in even carbon numbers [8], which can compete with natural fatty alcohol; the Oxo process is manufactured by hydroformylation of olefins and results in alcohols, which is branched. The Oxo fatty alcohol derivatives are widely used in applications that use cold water. Technical nonionic ethoxylated surfactants derivatives are not always uniform in composition depending on the type of catalyst used [8], such as potassium hydroxide [9] or sodium methoxide.

The cloud point (C.P.) of nonionic ethoxylated surfactants is an important physicochemical property in which its solubility is directly related to the temperature. The aqueous nonionic surfactant solution becomes cloudy at higher temperature due to the breaking of hydrogen bonds that cause insolubility at high temperatures. There is a unique relation between the hydrophilic ethylene oxide chain and the hydrophobic alkyl chain [3] in which molecules with an average alkyl chain length of 12 C atoms and containing more than 5 EO units are usually soluble in water at room temperature [2].

The cloud point of a surfactant is an important factor to be considered in surfactant screening for specific applications, because of the surprising changes in physical properties and, hence, in performance of a surfactant solution near the cloud point temperature. Clouding is to be avoided in some applications, for example surfactant-mediated soil remediation, which is operated at a temperature range in which clouding separation does not take place [10]. The cloud point can be tailored to desired levels to meet the requirements of applications.

The C.P. is also affected by the presence of electrolyte in the aqueous solution. Most electrolytes lower the C.P. of a nonionic surfactant solution [11, 12]. The addition of small amounts of anionic surfactants markedly increases the C.P. of nonionic surfactants [13]. This is due to the anionic surfactants inserting themselves in the micelles and modifying the surface charge leading to inter-micelle charge repulsion and their stabilization [14]. For fatty alcohol ethoxylates (FAEs), the CMC increases with the length of the PEG segments [15, 16], and consequently, the surface tension of their solutions increases.

Nonionic surfactants have a wide range of industrial applications in areas such as emulsifiers, detergents, and cleansers, health and personal care, agriculture, textile, paper industry, coatings, and emulsion polymerization, to name a few [5]. Concerning their importance, FAEs have been studied very intensively with regard to their ecotoxicity and can be regarded as environmentally safe [17].

In the present study the synthesis of two nonionic FAE surfactants with varying solubility ranging from water-insoluble to water-soluble obtained by changing the length of the hydrophilic polyethylene glycol (PEG) segment on the fatty alcohol was undertaken and their surface activity properties assessed. The prepared nonionic surfactants lauryl-myrisityl alcohol (LMA) ethoxylated with 3 and 31 mol of ethylene oxide is designated as LMAEO-3 and LMAEO-31, respectively. The generalized structure for lauryl-myrisityl alcohol (LMA) ethoxylated surfactants is shown in Scheme 1. The present work aimed also to evaluate these two nonionic surfactants as wetting agent for cotton fabrics, as anti-foaming agent and as MFFT reducer in polymer lattices.

Scheme 1
scheme 1

Generalized structure for lauryl myrisityl alcohol (LMA) ethoxylated surfactants (X = 3 or 31)

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Experimental

Materials

The reagents used in this experimental study include fatty alcohol (lauryl-myrisityl alcohol), VVF limited Co. India (trade name Vegarol®1214).

Ethoxylation of Vegarol®1214

All laboratory experiments were conducted in a 2-L autoclave. Vegarol®1214 was charged into a high pressure stainless steel autoclave with KOH (1.0 wt%) as a catalyst at 130 °C with continuous stirring, while passing a stream of nitrogen gas through the system for 10 min to flush out the air. The nitrogen stream was then closed and replaced by two different molar ratios 3 and 31 units of ethylene oxide (EO) [18]. The reaction completion was accepted when the pressure reached to its minimum value. At this stage, heating was stopped and the vessel contents were cooled. After cooling, the product obtained was neutralized with acetic acid. The yield was then collected. The FAEs (LMAEO-3 and LMAEO-31) obtained appeared as a colorless viscous liquid appearance.

Characterization of the Ethoxylated Nonionic Surfactants

The chemical structure of the prepared nonionic surfactants was confirmed by the FTIR and 1HNMR spectra. FTIR was carried out using Pye Unicam SP1200 spectrophotometer using KBr Wafer technique in the region from 4000 to 500 Cm−1. 1H-NMR spectra were determined on Varian Gemini 200 MHZ (CDCl 3 ) using TMS as internal standard (chemical shift in δ-scale).

Surface Tension Measurements

The surface tension measurements were undertaken for different concentrations of the novel prepared LMAEO-31 non-ionic surfactant dissolved in double distilled water with a surface tension equal 72 mN m−1 at 25 °C according to the method described in ASTM Designation: D1331-89 with a Krüss Tensiometer using a Du Nouy ring at constant temperature (25 ± 1 °C) [19]. Apparent surface tension values were given as a mean of three consecutive measurements.

Critical Micelle Concentration (CMC)

The critical micelle concentration value of prepared novel prepared LMAEO-31 nonionic surfactant was determined using surface tension measurements where surface tension values of aqueous solutions of our prepared surfactants were plotted against the corresponding concentrations. The interrupt change in the surface tension-concentrations curves will expresses the critical micelle concentration.

Determination of the Cloud Point of the Prepared Nonionic Surfactants [20]

Nonionic surfactants are usually characterized by their cloud point. The cloud point (C.P.) is determined by heating of 1 wt% surfactant solution in deionized water until it becomes cloudy and then determining the temperature at which clear solution is obtained as the solution cools. These procedures were repeated at least three times, and the C.P. temperatures were determined with a reproducibility of ± 0.2 °C. Apparent cloud point (C.P.) values were given as a mean of three consecutive measurements [12].

Measurements of Foaming Properties [21]

In application and research laboratories, this test is widely used to characterize foamability of surfactant solutions and foam stability in the absence or presence of an anti-foaming agent. In our experiments [22], a certain amount of the prepared nonionic surfactant (typically 0.1 wt% of aqueous surfactant solution) was pre-emulsified by stirring for 10 min on a magnetic stirrer. The obtained emulsion was additionally homogenized shaking by hand several times before placing it into a glass cylinder and circulating for 20 s. The solution foaminess is determined by initial foam volume, i.e., after stopping the aqueous surfactant solution circulation. The dynamic foam was formed during the circulation of the liquid, which had almost constant height/volume after, e.g., 30 s of circulation. Dynamic foam height (DFH) which is characterized by the steady-state height of the dynamic foam was measured and was used as a quantitative measure for the foamability of the solutions. The stability of foam was calculated by using the following equation [23]:

$${\text{Foam stability }}\left({\%} \right) = \frac{{{\text{Foam volume after }}5 \, {\text{mins}}}}{{{\text{Foam volume after }}0 \, {\text{mins}}}} \; \times \;100$$
(1)

Emulsifying Capability

To investigate the emulsifying capability, three types of monomers [styrene (St), butyl acrylate (BA), and methyl methacrylate (MMA)] were blended individually at equal volumes of 5 mL with 2 % aqueous surfactant solution, respectively. The time of testing is from 0 to 24 h. Separation rate is calculated as the following formula:

$$R_{{\mathbf{s}}} = V_{{\mathbf{s}}} \; \times \; 1 0 0/V_{{\mathbf{0}}}$$
(2)

where V 0 is the initial volume in mL of emulsion, R s  % is the separation rate percent, V s is the volume of water in mL separated from the emulsion.

Draves Wetting Measurements

The wetting power of aqueous surfactant solutions is often measured by some dynamic method such as the Draves skein wetting test [26]. On the other hand, the wetting power can also be measured by the rate and extent of the spreading of the solution on some nonporous planar substrate [27]. There is often a distinct difference in the behavior of an aqueous solution of a particular surfactant as measured by these two types of tests, even when both substrates are hydrophobic.

A 5 g skein of gray, unwaxed cotton, folded to form 9-in. loops, (54-in. loops containing 120 threads, purchased from Test fabrics, Inc., Middlesex, NJ, USA), was attached to a 1.5-g hook and totally immersed in a tall cylinder of different concentrations of surfactant solution. Surfactant solutions were prepared from deionized, distilled water. All measurements were made twice at 25 ± 1 °C [28].

Evaluation of LMAEO-3 as Anti-Foaming

Foaming test for measuring the foam stability in the absence and presence of LMAEO-3 surfactants as an anti-foaming agent or defoamer is used to characterize antifoam activity. A certain amount of the defoamer was pre-emulsified by stirring in a definite volume of surfactant solution for 10 min using a magnetic stirrer. Under fixed conditions, foam volumes ratios produced in the presence and in the absence of anti-foaming agent is used in the characterization of the effect of the defoamer on the foamability [22]. The result strongly depends on the specific experimental conditions: anti-foaming agent concentration [29], duration, and intensity of agitation [30–32].

Evaluation of LMAEO-3 as MFFT Reducer

MFFT were determined using a Rhopoint MFFT 60 (East Sussex, UK). The method used here for measuring MFFT followed ASTM Method D2354 [33]. The MFFT of commercially available pure acrylic latex before and after adding different Wt% of LMAEO-3 and butyl carbitol is measured for evaluation of the prepared ethoxylated fatty alcohol LMAEO-3 nonionic surfactant as MFFT reducer of emulsion lattices films.

Results and Discussion

Ethoxylation of Vegarol®1214 Fatty Alcohol

It is known that a typical ethoxylation run consists of a sequence of operational procedures, which includes a vessel pressure test, raw materials charge, dehydration, ethylene oxide addition, and product neutralization. All experiments were conducted at a constant reactor temperature and pressure, the agitation speed, catalyst concentration of 130 °C, 1.5 bar, 1700 rpm, 1.0% w/w of potassium hydroxide based on the starting Vegarol®1214, respectively. In order to prevent competitive polyoxyethylation of water during the ethoxylation of lauryl-myrisityl alcohol (LMA) significant effort must be made to remove residual water, which produces polyethylene glycol with ethylene oxide. The water is initially introduced to the reactor system from the addition of aqueous potassium hydroxide. More water was formed during the activation step. The removal of the water facilitates the high conversion to the potassium salt. Hall and Agrawal [34] investigated the effect of water content on the ethoxylation rate and found that a 32-fold increase of water content in fatty alcohol resulted in a 22% increase in the reaction rate. They suggested that the effect of residual water on the reaction rates became insignificant when the water content in a hydrophobic substrate is kept sufficiently low (e.g. at 0.04% by weight). Van Os [5] suggested the water content to be lowered to a level less than 0.1% by weight. In our experimental work, it was decided that the water content in the raw materials was removed to a level below 0.05 % by weight.

Characterization of Ethoxylated Nonionic Surfactants

FTIR Spectra of the Novel Prepared Ethoxylated Surfactants

The structural moieties [35] for the prepared lauryl-myrisityl alcohol ethoxylated surfactants that can be justified spectroscopically by infrared spectroscopy are summarized in Table 1. Figure 1a, b represents FTIR spectrograms of LMAEO-3 and LMAEO-31 surfactants, respectively. It is clear that the increasing in the ethylene oxide (EO) units in the prepared surfactants LMAEO-31 have great effect on the shape of the O–H stretching band which is characterized by a broad and flat pattern.

Table 1 Assignment of the IR-absorption bands to fatty alcohol lauryl-myrisityl alcohol (LMA) surfactants
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Fig. 1
figure 1

FTIR spectrograms of the novel prepared surfactant, a LMAEO-3, b LMAEO-31

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It is worth mentioning that broad and flat pattern which is unique for intramolecular hydrogen bonds [35]; see the O–H stretching band for FTIR spectrogram of prepared nonionic lauryl-myrisityl alcohol (LMA) ethoxylated (LMAEO-31) surfactant in Fig. 1b.

1H NMR Spectra of Ethoxylated Surfactants

Figure 2a, b represents 1H NMR spectrograms of the novel prepared LMAEO-3 and LMAEO-31 surfactants, respectively.

Fig. 2
figure 2

1H NMR spectra of the prepared a LMAEO-3 surfactant in CDCl3, b LMAEO-31 surfactant in CDCl3

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1H NMR(300 MHz, CDCl 3 ) for the novel prepared LMAEO-3 surfactant in CDCl3: δ 3.1 (s, –OH), 3.6 (br s, –(OCH 2 CH 2 )n–), 2.9 (m,–CH(CH2)2(OCH2CH2)n–), 1.6 (m, –CH 2CHO–), 1.1 (m, –(CH 2)nCH3), 0.72 (m, –(CH2)nCH 3).

1H NMR(300 MHz, CDCl 3 ) for novel prepared LMAEO-31 surfactant in CDCl3: δ 3.1 (s, –OH), 3.8 (br s, –(OCH 2 CH 2 )n–), 2.6 (m, –CH(CH2)2(OCH2CH2)n–), 1.6 (m, –CH 2CHO–), 1.1 (m, –(CH 2)nCH3), 0.72 (m, –(CH2)nCH 3).

Both FTIR and 1H NMR results can provide evidence of synthesis of the novel nonionic surfactants is successful.

Surface Tension Measurements

The surface tension (γ) of water originates from hydrogen bonds between the water molecules at the air–water interface. If the surfactant adsorbs at the interface, it breaks the hydrogen bonds, and consequently, the surface tension of the water surface will decrease lower than 71.8 mN m−1at 25 °C [19]. Here, the surface tension of surfactants was measured for different concentrations of the novel prepared LMAEO-31 nonionic surfactant above and below the critical micelle concentration (CMC). Figure 3 represents plot of γ versus lnC concentration for LMAEO-31 nonionic surfactant in deionized water. The surface tension curve shows an obvious descending as the concentration of aqueous surfactant solution increases. This means that the surfactant molecules are highly adsorbed at the water interface. As long as the concentration of the surfactant molecules increases, the surface tension values will remain stable. When these two regions are intercepted, this gives the concentration at which the surfactant micelles are formed (CMC) [19, 36]. This observation was recorded for the novel prepared LMAEO-31 nonionic surfactant up to the CMC, beyond which no considerable changes were noticed.

Fig. 3
figure 3

Surface tension of lauryl-myrisityl alcohol ethoxylate (LMAEO-31) surfactant versus its concentrations in water at 25 °C

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The CMC data obtained from the intercept in the γ- lnC plots is shown in Table 2. The ethylene oxide EO chain length increases the hydrophilicity of the nonionic surfactants due to the ether bond leads to increasing CMC values and increasing in the depression of the surface tension at this concentration.

Table 2 Surface tension (γ) and critical micelle concentration (Ccmc) of the prepared LMAEO-31 non-ionic surfactant from surface tension measurements at 25 °C
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Hydrophilic–Lipophilic Balance (HLB) of Prepared Nonionic Surfactants

To correlate the structure of surfactant molecules with their surface activity, Griffin developed the concept of hydrophilic–lipophilic balance (HLB) [37]. HLB values may be calculated for nonionic surfactants or may be determined experimentally. The experimental procedure is long and laborious and was described few years ago [38]. HLB values were calculated with the Griffin formula based on the ethylene oxide moiety in the molecule [3] as follows:

$${\text{HLB}} = 20X\frac{{{\text{MW}}_{\text{H}} }}{{{\text{MW}}_{\text{H}} {\text{ + MW}}_{\text{L}} }}$$
(3)

where MWH = Mol. Wt of the hydrophilic part and MWL = Mol Wt of lipophilic part. Table 3 shows the HLB values calculated with the Griffin formula for the novel prepared surfactants. It is clear from Table 3 that HLB generally increases with increasing number of ethylene oxide units per surfactant molecule [39].

Table 3 Cloud point values, HLB values calculated with the Griffin formula for prepared surfactants
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Determination of the Cloud Point (C.P.) of the Prepared Nonionic Surfactants

It is known that when aqueous nonionic surfactant solutions are heated to a certain temperature and clouding behavior is exhibited at this temperature (cloud point, C.P.). Table 3 shows the cloud point values for the prepared LMAEO-31 nonionic surfactant. Cloud point determination is useful in judging the storage stability of products and provides information about the storage temperature that may lead to instability or phase separation. It is worth mentioning that optimum effectiveness is obtained for the nonionic surfactants below their cloud point.

Measurements of Foaming Properties

Excessive foaming leads to reducing operating efficiencies and added expenses for foam-control. The LMAEO-31 surfactant exhibited foam height and foam stability lower than the anionic Bis (2-ethylhexyl) sulfosuccinate, disodium salt (Bis 2-EHSSC), these results are in accordance with the data previously reported [40, 41] in which aqueous nonionic surfactant solutions show foam volume and foam stability smaller than the anionic surfactants. This is attributed to the absence of highly charged films in these foams and their larger surface area per molecule.

Because of the molecular structure of LMAEO-31, it tends to produce less stable foams than other nonionic NPEO-30 (4-nonyl phenol ethoxylated with 30 EO molecules) surfactant. This property is illustrated in Table 4 for the prepared nonionic surfactants. While all surfactants generate significant foam initially, the foam produced by LMAEO-31 dissipates faster than that produced by the other nonionic NPEO-30 surfactant.

Table 4 Initial and 5-min foam heights for the prepared surfactants
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It can be concluded that LMAEO-31 appears to have moderate foaming properties and exhibited not only moderate foam height production at zero time, but also low-foaming height stability after 5 min. The LMAEO-31 surfactant exhibits a low foam height after 5 min and are suggested as a good surfactant for oilfield water treatment and exhibited low foam stability, and thus has a good detergency power, as reported before [42].

Emulsifying Capability

The emulsion formation by the aid of surfactants is accomplished by the effect of adsorption, and forming adsorptive film layer at the interface of dispersed droplets, which can delay collision among emulsion droplets and may cause gathering and condensation of the system. The adsorption effect of the oil–water surface in the O/W emulsion is scaled by the degree of damage of the structure of the water phase by the effect of the hydrophobic groups, and consequently the adsorption effect increases with the increase in length of the hydrophobic chain [43]. For determining emulsifying capability [24], the separation rate versus time is shown in Table 5.

Table 5 Separation rate versus time with different monomers if LMAEO-31 is used as emulsifying agent
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The results revealed that the stability of emulsions depends not only on the substrate (i.e. monomers), but also on the hydrophilic chain length of the surfactants in which the stability of emulsion became excellent as the hydrophilic property of monomer increasing [44]. On the other hand, the stability of emulsion became excellent by increasing length of hydrophilic EO chains which provide steric stabilization for particles due to more hydrogen bonding.

Draves Skein Wetting Test

In many industrial processes, the wetting of solid surfaces by liquids is practically important (e.g. the ability of a surfactant to wet textile substrates). The Draves wetting test [25, 26] is a laboratory procedure widely used for rating the surfactants wetting efficiencies relative to its aqueous solution. The Draves wetting test is a time-dependent test for determining the wetting of a cotton skein by dilute aqueous surfactant solutions, where short wetting times refer to excellent relative wetting efficiencies and this may attributed to the air in the skein is displaced by the aqueous surfactant solution and when it displaced sufficient air, suddenly the cotton skein sank in the cylinder. Table 6 shows the Draves wetting times for the LMAEO-31 nonionic surfactant.

Table 6 Draves wetting Times for the prepared LMAEO-31 at conc. of 0.05 Wt % and 0.15 Wt % of surfactant solutions
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It is clear that the LMAEO-31 nonionic surfactant is an excellent wetting agent because the lower the concentration of surfactant needed for sinking in a given time, the more efficient the wetting agent is.

Evaluation of LMAEO-3 As Anti-Foaming Agent

Minimizing foam generation is desirable in many industrial applications because excessive foaming might create serious problems. Anti-foaming agents are indispensable additives that are widely used in different technologies to overcome the problem of excessive foam generation [31, 45]. Anti-foaming agents are the substances pre-dispersed in the foaming solution as oil drops, solid particles, or mixed oil-solid globules to prevent formation of excessive foam forming the so-called entry barrier, which indicates how pre-dispersed anti-foaming agent molecules particles to pass through the air–water interface, while defoamers, in contrast, are substances sprinkled over an already formed foam column to induce rapid foam collapse.

Tables 7 and 8 shows foam evolution, in the presence of the LMAEO-3 surfactant. The foam height, is monitored as a function of time, t. It can be seen that the LMAEO-3 nonionic surfactant appear to have no foaming properties and the anionic surfactant Bis (2-ethylhexyl) sulfosuccinate, disodium salt exhibited a high foam height production at zero time, and also high stability after 5 min.

Table 7 Initial and 5-min foam heights for the prepared LMAEO-3 nonionic surfactant and the prepared anionic surfactant Bis (2-ethylhexyl) sulfosuccinate disodium salt
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Table 8 Results from the Foaming test (ASTM D1173, distilled water, 25 °C, 0.10 wt% solutions) with 0.10 wt% Bis (2-ethylhexyl) sulfosuccinate, disodium salt solution, containing 0.01 wt% LMAEO-3
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In the contrary, when 0.01 Wt% of LMAEO-3 was pre-dispersed in the aqueous surfactant solution, in which the foam height, is monitored as a function of time, the foam height initially stayed below 10 mL, and this could be attributed to the anti-foaming agent. After Stage 1 (2800 s), a sudden complete loss of the anti-foaming agent activity is observed which indicates the moment of antifoam exhaustion, when the process of bubble destruction becomes too slow to compensate for the bubble generation and, as a result, the value of the foam volume starts increasing very rapidly with time.

Evaluation of LMAEO-3 As MFFT Reducer

Emulsion polymers or lattices are applied extensively in water-based coatings. The latex primarily present as a colloidal dispersion of dispersed particles in water and during drying is transformed into coalesced and mechanically coherent polymer film as long as the application temperature exceeds the minimum film forming temperature (MFFT) of the coating system [46]. During drying, initially water is evaporated at a constant rate, and then the evaporation rate slows until water loss is complete.

The MFFT of commercially available pure acrylic latex before and after adding different Wt% of LMAEO-3 and butyl carbitol it is measured for evaluation of the prepared ethoxylated fatty alcohol LMAEO-3 nonionic surfactant as MFFT reducer of emulsion lattices films. The results are presented in Table 9.

Table 9 MFFT values of commercially available PA latex film before and after adding different Wt% of LMAEO-3 and butyl carbitol as MFFT reducers
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The prepared PA dry latex film exhibits severe cracking in the winter (i.e., temperature usually lower than 10 °C) and after drying the clear polymer film exhibited apparent haziness. This could attributed to upper-top layer of the film is dried quickly, while the under laying latex dries at a slower rate. This causes stress increase and consequently led to cracking of the polymer film. The results revealed that the MFFT of the PA dry latex film approximately equal 22 ± 1 and the MFFT of PA dry latex film decreases as expected when the content of butyl carbitol and the prepared non-ionic LMAEO-3 surfactant is increased. It was also observed that the PA latex film remains opaque for a longer time during drying. This suggests that the water is released in an overall slower way and that a more uniform drying behavior is obtained giving very smooth clear polymer films with a high gloss at MFFT approximately equal 5 ± 1. This will probably have a positive influence on the open time when formulated in a coating and may, therefore, be beneficial for the development of glossy water-based paints. Lower MFFT was adequate to extend the construction and application temperature of the latex paint [47].

Conclusion

The conclusion of this research project can be summarized in the following points

  • Two nonionic FAE surfactants have been synthesized successfully. The T FAE surfactants having different units of ethylene oxide (n = 3, 31) were synthesized by the reaction of Vegarol ®1214 (lauryl-myrisityl alcohol) with ethylene oxide gas to yield LMAEO-3 and LMAEO-31, respectively.

  • These novel nonionic FAE surfactants their chemical structures were confirmed by IR spectra, 1H NMR, and their surface active properties such as surface tension measurements, cloud points, foaming properties by Ross-Miles foaming test, emulsifying capability, and their hydrophilic-lipophilic balance (HLB) and comparing with each other have been investigated.

  • The surface tension for LMAEO-31 decreases with increasing concentrations of surfactant aqueous solutions. That indicates the high adsorption tendency of the surfactant molecules at the water interface.

  • An increasing in number of ethylene oxide units per surfactant molecule, resulted in increase of HLB.

  • Cloud point generally increases with increasing hydrophilic–lipophilic balance (HLB) of the nonionic surfactants, corresponding to an increasing number of oxyethylene units per surfactant molecule.

  • The LMAEO-31 nonionic surfactant appears to have moderate foaming properties compared to Bis (2-ethylhexyl) sulfosuccinate, disodium salt (Bis 2-EHSSC) and NPEO-30 and exhibited a moderate foam height production at zero time and also low-foaming height stability after 5 min.

  • Draves wetting times for the prepared LMAEO-31 nonionic surfactant proved that this surfactant is excellent wetting agent. The lower the concentration of surfactant needed to cause sinking in a given time, the more efficient is the wetting agent.

  • The stability of emulsion prepared by using the prepared LMAEO-31 nonionic surfactant became bad and may be judged by increase of the separation rate as the hydrophilic property of monomer weakened.

  • The prepared LMAEO-3 non-ionic surfactant exhibited excellent defoaming properties.

  • The results revealed that the MFFT of the commercial PA dry latex film approximately equal 22 ± 1 and the MFFT of PA dry latex film decreases as expected when the content of butyl carbitol and the prepared nonionic LMAEO-3 surfactant is increased, i.e., the prepared LMAEO-3 nonionic surfactant exhibited excellent MFFT reduction.