WO2015121873A1

WO2015121873A1 - Polymeric surfactant and its prepartion

Info

Publication number: WO2015121873A1
Application number: PCT/IN2014/050005
Authority: WO
Inventors: Dr. Bhalchandra GOGTE
Original assignee: Green Hydrocreatives Pvt. Ltd.
Priority date: 2014-02-12
Filing date: 2014-12-23
Publication date: 2015-08-20
Also published as: IN2014DE00396A

Abstract

The present invention discloses a polymeric surfactant comprising one or more carbohydrates, carboxylic acids to enhance the characteristics of said surfactant and anhydride as regulators to regulate the molecular weight of said surfactant wherein the said polymeric surfactant is biodegradable with enhanced detergency par and its method thereof.

Description

POLYMERIC SURFACTANT AND ITS PREPARTION

FIELD OF THE INVENTION

The present invention relates to preparation of surfactants using biodegradable polymers wherein the polymers used in the preparation of surfactants are derived from natural sources. BACKGROUND OF THE INVENTION

In general, anionic surfactants were used in various industries which are harsh, in order to reduce the harshness of anionic surfactants, non-ionic or other mild surfactants (e.g., amphoteric) are utilized. The use of non-ionic surfactants led to the problems such as non generation of creamy thick lather; which can be sticky and can introduce processing difficulties. Anionic surfactants mainly Linear Alkyl Benzene Sulphonic Acid (LABSA) and DDBSA are commercially used as they give rich lather. Non-ionic surfactants like Sodium Lauryl Ether Sulphate & Alpha Olefin Sulfonates are commercially used in place of anionic surfactants. As these non-ionic surfactants have petroleum base but the major problem associated with them are their scarcity and their high cost. Use of above mentioned chemical based surfactants has been used in various industries but have drawbacks such as hazardous environmental impact. The non-ionic detergents having petroleum base also cause harm to aquatic flora and fauna. These detergents are responsible for foaming and eutrophication.

For these reasons, there is a requirement for materials which are milder than anionic surfactants and/or available at low cost. By using vegetable based polymers in detergent formulations the mentioned problems of water pollution can be minimized to greater extent. As well as these polymers, obtained from natural sources are low in cost and biodegradable. Also the surfactants using these polymers are available at low cost as compared to any anionic surfactant and at par with detergency action. These eco-friendly surfactants have applications in various industries. SUMMARY OF THE INVENTION

The present invention describes a method to prepare a polymeric surfactant using carbohydrate as a source of raw material. The polymers of carbohydrate has been used in prior art to prepare biodegradable materials. The present invention uses the said property of carbohydrate to prepare surfactants to replace the ionic and non- ionic surfactants known in the market. These surfactants lead to environmental pollution and also available at higher cost as they use petroleum base. The present invention uses the naturally obtained sugar base to prepare polymer thus resulting in cheaper and eco-friendly surfactant. The polymer is prepared by homogenising the mixture of carbohydrates, sugar alcohol, acids and their derivates and alkali salts at optimum conditions. The resulting polymer has high detergency, low acid valve, biodegradable, low cost of production thus resulting in a better surfactant.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is explained in greater detail below. This description is not intended to be a detailed catalogue of all the different ways in which the invention may be implemented, or all features that may be added to the instant invention. For example, features illustrated with respect to one embodiment may be incorporated into other embodiments, and features illustrated with respect to a particular embodiment may be deleted from that embodiment. In addition, numerous variations and additions to the various embodiments suggested herein will be apparent to those skilled in the art in light of the instant disclosure, which do not depart from the instant invention. Hence, the following specification is intended to illustrate some particular embodiments of the invention, and not to exhaustively specify all permutations, combinations and variations thereof.

Chemical surfactants and emulsifiers assemble at the interface between water and a polar liquid, where they form interfacial films. Surfactants are soluble compounds that reduce the surface tension of liquids or interfacial tension between two liquids or a liquid and a solid whereas, an emulsifier does not necessarily decrease the surface tension or interfacial tension but helps in dispersion of droplets of one immiscible liquid within another and prevents them from coalescing. Among the desirable characteristics of surfactants are solubility, surface tension reduction, low critical micelle concentration, detergency power, wetting ability and foaming capacity, which make them highly desirable for many applications. Chemical based surfactants and emulsifiers have been used in various industries but most have hazardous environmental impact and therefore availability of a less toxic or non-toxic biosurfactants was desirable.

Increased interest in the potential applications of bio based surface active agents has been due to their broad range of functional properties that include emulsification, wetting, foaming, phase separation, solubilisation, de-emulsification, cross inhibition and viscosity reduction of heavy crude oils. They have also been reported to be used in personal care, pulp & paper, coal, ceramics and uranium ore processing. The industrial use of biosurfactants has been limited due to higher production costs, expensive substrates and inefficient production technologies compared to chemical surfactants.

The polymers containing carbohydrates are unique as they are potentially processable and biodegradable and biocompatible polymers. Synthesis of carbohydrate polymers based on sugar, sorbitol, maize starch, acid anhydrides for example: Phthalic and Maleic, and small quantity of carboxylic acid has been attempted. The carboxylic acids have been specially used to study their effect on foam, detergency and stain removing characteristics. In this synthesis various catalysts like HC1, Sodium bisulphate, Sodium bisulphite have been used.

The detergents made out of acid slurry cause harm to aquatic flora and fauna. Acid slurry has a petroleum origin. The detergents are responsible for foaming and eutrophication. By using vegetable based polymers in detergent formulations the above mentioned problems of water pollution can be minimized to a greater extent.

The polymeric surfactants are prepared based on natural products of vegetable origin like maize starch, sorbitol, vegetable oils, sugar and glycerin in synthesis of polymeric surfactant along with acid anhydride like maleic and phthalic anhydride (shown in table 1). These novel polymers have been used in formulation liquid, powder and cake detergents as partial or total replacement of acid slurry of petroleum origin. Addition of carboxylic acids step up the polymeric surfactant in reference to foaming, detergency and reduction of surface tension. Sugar on hydrolysis with water splits to glucose and fructose which are potential source of hydroxyl groups. The -OH group from carbohydrate and -COOH group of anhydride, carboxylic acid result into esterification reaction resulting into biosurfactant.

The synthesis of polymers is carried out in a reactor wherein said reactor consists of two parts an upper part and a lower part. The upper part of the reactor is its lid, having four necks with standard joints. Motor driven stirrer was inserted in the reactor through the central neck, while another neck was used for thermometer. A Condenser was fitted with the reactor through the third neck. And the further neck was used for dropping the chemicals in to the reactor. The reactor was heated by an electric heating mantle having special arrangement for smooth control of the temperature of the reactor. A regulator controlled the speed of the stirrer. Example 1:

Three batches of polymer were cooked using the above process. The cooking schedule is shown in table 2. The % yield in all the batches is of order of 90 to 94%. In various batches maleic anhydride has been used the possible chemical reaction are esterification of OH group in carbohydrate ingredients and acidic groups in maleic and phthalic anhydride. A small quantity of Benzoic acid has been used as chain stopper citric acid and oxalic acid have been incorporated with a view of improving detergency.

The substrates can be any individual or a combination of sorbitol, starch, dextrine, glycrine, or any vegetable oil. The intramolecular or intermolecular esterification to be used can be individual or either combination of maleic anhydride, pthalic anhydride, citric acid, oxalic acid. To regulate the ideal most pH for facilitating the reactions Sodium bisulfite, Sodium metabisulfite and Sodium bisulphates are used in combinations and as indicated in the Table 1.

TABLE 1: Composition of Polymer

The governing factors in delivering the best configuration are flow index, long term stability of the product, colour, odour & pH. With maximum sorbitol percentage the highest performance in terms of detergency, transparency, highest polymer weight is obtained. Decreasing Sorbitol and increasing starch results in hazy appearance, higher viscosity, stability problems in presence of acidic conditions, decreased shelf life and lower detergency values.

Variants with higher sugar content tend to get caramelized in due course of the preparation process thus imparting strong dark colour which ultimately leads to tarnished detergent formulations. Higher sorbitol requires longer cooking time to achieve the desired percentage solids due to presence of higher water content in sorbitol. Polymers with starch higher starch contents exhibit string affinity towards binding with bivalent ions i.e. calcium and magnesium, indicating higher efficacy in hard water conditions on detergency. To improve colour of any variant optical brighteners have been used.

With respect to the textile applications for strong wetting and decreasing surface tension requirements, highest sorbitol grade proves to be most effective due to high penetrating power.

To optimize the flow indexes, the solids are maintained to 80-85% with varying raw materials. With decreased percentage of solids, the detergency is below par with the conventional grades of sulphonated anionic surfactants. At low percentage solids, the bulk density of the detergent powder is seriously impacted. Higher solid grade of surfactant provides strong binding in detergent cake preparation.

All the reactants are charged into a premixing vessel where starch, sorbitol and glucose are homogenized using a stirrer or agitator, followed by addition of all other catalysts or acids. However the order of addition was found not to exhibit any change in the properties of the end product. The temperature profile of the entire process is critical with respect to the colour of the product and its percent solids. Sudden rise in temperatures resulted in losses of anhydrides and to avoid this, a water cooled condenser is installed in order to recover vapours lost and recharge into the same batch. When the temperatures exceeds beyond the said temperature in table 2, the polymer gets degraded.

TABLE 2: Cooking Schedule of Polymers

(Temp, in °C measured after cooking period of sec.)

The Neutralization of Polymer is done using at least 30% KOH and maintained at optimum temperature of 60°C and pH of 8. Further the physicochemical analysis and spectroscopic analysis of three polymers were undertaken, shown in table 3. TABLE 3: Physico-chemical Analysis of Polymers

The end product was standardized against the physico-chemical properties like acid value, ester value, % solids and viscosity to terminate the reaction. TABLE 4: Stain Removing Characteristics of Various Polymers

Powdered detergents is prepared using B 1 polymer. The said ingredients and the composition of detergents powder are as shown in the formulations. The said ingredients in the powdered form are weighed and mixed thoroughly in tray. Then add liquid ingredients linear alkyl benzene sulphonate, Alpha olefin sulphonate and neutralized resin. Whole mass is then homogenized thoroughly. After mixing, the homogeneous mass thus obtained is air dried. A special type of Whitener is developed by addition of Titanium Dioxide (50%) and Sorbitol (50%). and then 1 % of this mixture is added to the composition. Paste is prepared by mixing robin blue and sorbitol in 1 : 1 proportion. This paste in added to the composition of powder detergent.

TABLE 5: Powder Detergent Based on B l Polymers

TABLE 6: Analysis of Powder Detergents at 1.0% cone.

EXAMPLE 2

The another grade of polymeric surfactant was prepared based on following composition to achieve further low manufacturing costs;

TABLE 7: Composition of Polymers

The reaction temperature was controlled within +/- 2 C accurate temperature control in heating mantle.

Four polymers with desire characteristics are shown in Table no. 7. Major ingredient was sorbitol and sugar solution has been used. The higher proportion of sugar result in charring so the limit to which sugar can be tolerated is found to be 28-30%. A small amount of starch power has been used in composition B land B3. A variety of catalyst have been tried which include Hydrochloric acid, tween 80, Sodium bisulphite and Sodium bisulphate. Hydrochloric acid appears to give desirable result. The preliminary physicochemical analysis is given in Table no. 8 the acid values are quiet low in the range of 4-12 this indicate esterification reaction between acidic group of phthalic & maleic anhydride and OH group of starch, sorbitol, and sugar. The cooking schedule and composition is given in table no.2.

TABLE 8: Physicochemical Properties of sugar sorbitol based polymers

The commercial scale reactor is designed in stainless steel low carbon to avoid any corrosion of the material into the product. A variable frequency drive fitted agitator is used to minimize foam generation and constant mixing of the reactants. A foam breaker is installed to avoid overriding of the reactants out of the vessel. The entire operation is carried out at ambient pressure or under partially vaccuated conditions to minimize vapour losses.

Preparation of novel polymer obtained from natural sources using microwave method will increase the applicability of these polymers in various industries. The polymer can be used as primary surfactants with biodegradable property, in textile industries as scouring and wetting agents. Novel polymer can further be used as Pre sizing agent/binder for non cotton based warps. The polymer can be used as water softening polymer for effluent treatment systems. This polymer is basically modified starch and graft co polymer having a high molecular weight of more than 25,000 daltons.

The polymer can be used as flocculation agent of polyelectrolyte for coagulating in settling systems of Effluent treatment plants. These polymers are also used to decrease the surface tension remarkably used for fulling of blanket/wool industry. The fulling involves the scales of the wool to open up and intertwine spatially resulting in a thicker and stronger wrap. This requires decreased surface tension of the working medium and lubricity.

These polymers can replace aklyl sluphonates for creating high molecular weight Poly vinyl alcohol polymers in oil well drilling applications. These polymers are used for increasing the viscosity at lower concentrations of the drilling fluid which is required to create overbalancing pressure in the reservoir. The advantage of carbohydrate polymers over alkyl sulphonated polymers is that the viscosity of the later is severely decreased by the presence of cations in saline water. However the carbohydrate polymers instead result in increased viscosities. The foregoing is illustrative of the present invention, and is not be construed as limiting thereof. While embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes and substitutions will now occur to those skilled in the art without departing from the invention. In the claims that follow, the indefinite article "A", or "An" refers to a quantity of one or more of the item following the article, except where expressly stated otherwise. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

Claims

CLAIMS:

1. A Polymeric surfactant comprising;

at least one carbohydrate and its derivative in an amount ranging from 20% to 40% by weight,

sugar alcohol in an amount ranging from 50% to 85% by weight

carboxylic acids to enhance the characteristics of said surfactant at least 1.5% by weight, and anhydrides as regulators to regulate the molecular weight of said surfactant in an an amount ranging from 3% to 15% by weight.

2. The polymeric surfactant as claimed in claim 1, wherein the carbohydrate is selected from the group consisting of polysaccharide and monosaccharide.

3. The polymeric surfactant as claimed in claim 1, wherein the sugar alcohol is preferably a sorbitol.

4. The polymeric surfactant as claimed in claim 1 , wherein the carboxylic acid comprises at least one selected from the group consisting of citric acid and oxalic acid to regulate foaming, detergency and stain removing characteristics.

5. The polymeric surfactant as claimed in claim 1, wherein the anhydride comprises at least one selected from the group consisting of maleic anhydride and phathalic anhydride.

6. The polymeric surfactant as claimed in claim 1 , wherein a catalyst is used to regulate the pH of the polymeric surfactant in an amount ranging from 1% to 8% by weight, preferably 4% by weight.

7. The polymeric surfactant as claimed in claim 7, wherein the catalyst is selected from the group consisting of alkali salts of sulphur oxides.

8. The polymeric surfactant as claimed in claim 1, wherein an aromatic acid preferably benzoic acid is used as a chain terminator.

9. The polymeric surfactant as claimed in claim 1, wherein the polymeric surfactant is prepared by homogenisation between individual or a combination of polysaccharide, monosaccharide, sugar alcohol, or any vegetable oil with carboxylic acid and anhydride in the presense of a catalyst.

10. The polymeric surfactant as claimed in claim 10, wherein the polysaccharide, monosaccharide, sugar alcohol can be in any ratio prefrebly with high sugar alcohol content and low polysaccharide content.