Alginate Fiber

7/21/2019 Alginate Fiber

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GROUP IGROUP I

PRESENTED BY.PRESENTED BY.

M.USMAN BAJWA ID #060820063M.USMAN BAJWA ID #060820063

M.SULAMAN MUSHTAQ ID #050620122M.SULAMAN MUSHTAQ ID #050620122

PRESENTED TO.PRESENTED TO. Mr. HAMMAD MOHSINMr. HAMMAD MOHSIN

UNIVERSITY OF MANAGEMENT & TECHNOLOGYUNIVERSITY OF MANAGEMENT & TECHNOLOGY

ALGINATE FIBERALGINATE FIBER

What is Alginate?What is Alginate?

Alginate is natural fiber which is extractAlginate is natural fiber which is extract

from plants. It is a viscous gum that isfrom plants. It is a viscous gum that isabundant in the cell walls of brown algae.abundant in the cell walls of brown algae.


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INTRODUCTIONINTRODUCTION

Alginate is found in a wide variety of brownAlginate is found in a wide variety of brown

seaweeds and is present as a structuralseaweeds and is present as a structural

polysaccharide. Alginate is made up of a linearpolysaccharide. Alginate is made up of a linear

block copolymer ofblock copolymer of --LL-- gularonicgularonic acid andacid and --DD--

mannuronicmannuronic acid .The type of structure isacid .The type of structure is

influenced by the seaweed source as well as theinfluenced by the seaweed source as well as the

growing conditions of the weed .growing conditions of the weed .

Alginate bearingAlginate bearingWWeeds are typically found ineeds are typically found in

temperature or cold water. Major commercialtemperature or cold water. Major commercial

sources of alginates are the giant kelp fromsources of alginates are the giant kelp from

California. The major manufacturers are based nearCalifornia. The major manufacturers are based near

the weed sources in San Diego, Scotland andthe weed sources in San Diego, Scotland and

Norway. More recently manufacturers have beenNorway. More recently manufacturers have been

developing in Asia.developing in Asia.

Alginate can also produced from a bacterial source.Alginate can also produced from a bacterial source.


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Photographs About Alginate .Photographs About Alginate .

Shore castShore cast LaminariaLaminaria..

Feed Seaweed.Feed Seaweed.


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Mixed Weed.Mixed Weed.

HISTORY OF ALGINATEHISTORY OF ALGINATE

CHEMISTRYCHEMISTRY

Algae are one of the worlds oldestAlgae are one of the worlds oldest lifeformslifeforms, being, being

present in the pre Cambrian era (Engel,present in the pre Cambrian era (Engel,

1961).Although the so called1961).Although the so called higher plantshigher plants

developed stems, leaves and a root system once thedeveloped stems, leaves and a root system once themarine algae hadmarine algae had utilisedutilised light in photosynthesis theirlight in photosynthesis their

development seems to have come to a halt.development seems to have come to a halt.


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WHAT IS SEAWEED?WHAT IS SEAWEED?

A Plant that grows in the ocean that is called asA Plant that grows in the ocean that is called asseaweeds.seaweeds.

Seaweed, name commonly used for theSeaweed, name commonly used for the multicellularmulticellularmarine algae. Simpler forms, consisting of one cell ormarine algae. Simpler forms, consisting of one cell ora few cells, are not generally called seaweed; thesea few cells, are not generally called seaweed; thesetiny plants help to make up plankton. The moretiny plants help to make up plankton. The morehighly developed types of seaweed usually have ahighly developed types of seaweed usually have a

basal disk, that is known as holdfast, and a frond ofbasal disk, that is known as holdfast, and a frond ofvarying length and shape, which often resembles avarying length and shape, which often resembles aplant in having stem like and leaf like parts.plant in having stem like and leaf like parts.

STRUCTURE OF ALGINATESTRUCTURE OF ALGINATE

FIBERFIBER

Alginate was originally thought to consist of aAlginate was originally thought to consist of a

uniform polymer ofuniform polymer of mannuronicmannuronic acid. theacid. the

presence ofpresence of guluronicguluronic acid residues and it is nowacid residues and it is now

understood that alginate is a linear counderstood that alginate is a linear co--polymerpolymer

ofof --DD--MannuronicMannuronic acid andacid and --LL--GuluronicGuluronic

acid.acid.

SodiumSodiumpolymannuronicpolymannuronic acidacid


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Depending on the weed source and growingDepending on the weed source and growing

conditions the ratio ofconditions the ratio of mannuronicmannuronic andand guluronicguluronicacid can vary. It is also known that the blockacid can vary. It is also known that the block

structure within the alginate can vary significantly.structure within the alginate can vary significantly.

The polyThe poly guluronicguluronic acid blocks bind significantlyacid blocks bind significantly

more effectively with calcium ions than the polymore effectively with calcium ions than the poly

mannuronicmannuronic acid blocksacid blocks

COCO--POLYMERPOLYMER

AA heteropolymerheteropolymer, also called a copolymer, is a, also called a copolymer, is a

polymer formed when two or more differentpolymer formed when two or more different

types of monomers are linked in the sametypes of monomers are linked in the same

polymer chain, The assembly of the monomers inpolymer chain, The assembly of the monomers in

the copolymers can be headthe copolymers can be head--toto--tail, headtail, head--toto--head,head,

or tailor tail--toto--tail.tail.


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11-- Homo polymerHomo polymer

22--Hetero polymer or alternatingHetero polymer or alternating

33--Hetero polymer , RandomHetero polymer , Random44--Hetero , block polymerHetero , block polymer

55--Hetero , branch polymer , graftHetero , branch polymer , graft

COCO--POLYMERIZATIONPOLYMERIZATION

It is the process using more than oneIt is the process using more than one

monomers to produce a copolymer, which willmonomers to produce a copolymer, which will

possess properties different to the homopossess properties different to the homo

polymer of either monomer. In manpolymer of either monomer. In man--mademade

plastics copolymerization is used to modify theplastics copolymerization is used to modify the

properties of the material to a specific needs, forproperties of the material to a specific needs, forexample to reduceexample to reduce crystinilitycrystinilitymodify glassmodify glass

transition temperature or to improve solubility.transition temperature or to improve solubility.


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COCO--POLYMER EQUATIONPOLYMER EQUATION

An alternating copolymer has the formula:An alternating copolymer has the formula: --AA--BB--AA--BB--AA--BB--AA--BB--AA--BB--, or, or --((--AA--BB--)n)n--. The molar. The molar

ratio of the monomer in the polymer is close toratio of the monomer in the polymer is close to

one, which happens when the reactivity ratios r1one, which happens when the reactivity ratios r1

& r2 are close to zero, as given by the Mayo& r2 are close to zero, as given by the Mayo--

Lewis equation also called the copolymerLewis equation also called the copolymer ..

Where r1 = k11/k12 = k22/k21 & r2.and r1 is ratioof M1 &r2 is the ratio of M2

M1=molecular wt of A(monomer)

M2=molecular wt of B(monomer)

PRODUCTION OF ALGINATEPRODUCTION OF ALGINATE

There are essentially two processes for theThere are essentially two processes for the

preparation of alginates. They all start off withpreparation of alginates. They all start off with

similar extraction procedures but vary in thesimilar extraction procedures but vary in the

methods used to precipitate the alginate at themethods used to precipitate the alginate at the

end of the process.end of the process.


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EXTRACTIONEXTRACTION

Raw or dried weed is washed with acid to

remove cross linking ions that cause the alginate to be

insoluble. The acid washed weed is then dissolved in

alkali, typically sodium hydroxide, to produce a

viscous solution of alginate and cell wall debris which

contains a lot of cellulose. The solution is filtered to

remove the cell wall debris and maybe treated to

remove color. Finally a clear, clean alginate solution isleft.

Calcium PrecipitationCalcium Precipitation

ACID PrecipitationACID Precipitation

Calcium PrecipitationCalcium Precipitation

This the most common and versatile of precipitationThis the most common and versatile of precipitationmethods is the calcium method. In this method calciummethods is the calcium method. In this method calciumsalts are added to the filtered liquor to produce a fibroussalts are added to the filtered liquor to produce a fibrousprecipitate. This fiber is then left to 'harden' before beingprecipitate. This fiber is then left to 'harden' before beingrecovered. One method of recovery involves blowing airrecovered. One method of recovery involves blowing airinto the tank and skimming the floating the fibrous matinto the tank and skimming the floating the fibrous mat

off the surface.off the surface.The recovered mat of calcium alginate is then treatedThe recovered mat of calcium alginate is then treated

with more acid to remove the calcium ions and leave anwith more acid to remove the calcium ions and leave aninsolubleinsoluble alginicalginic acid fiber. This fiber can then be mixedacid fiber. This fiber can then be mixed

with various alkali salts such as sodium carbonate towith various alkali salts such as sodium carbonate toform sodium alginate.form sodium alginate.


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ACID PrecipitationACID Precipitation

Another and more direct method of precipitation is

by using acid directly. This method has the advantage

that the calcium addition and subsequent removal is

avoided making an inherently simpler process. However

it will only work with certain strong gelling types of

weeds. With weeds such as Ascophyllum the acid

precipitate formed is too soft too press and dewater and

cannot be used. So in terms of seaweed types that canbe used this process is much less flexible.

PROPERTIESPROPERTIES

All alginate fiber are nonAll alginate fiber are non--inflammables. The number ofinflammables. The number ofpossible yarn is limited only by those metals whichpossible yarn is limited only by those metals whichgives in soluble salts withgives in soluble salts withAlginicAlginic acid withoutacid withoutdiscoloration.discoloration.

Yarn having a breaking strength of 2.00 gm perYarn having a breaking strength of 2.00 gm perdenier per filament have been produce .denier per filament have been produce .

Another property suggested is the wrapping of theAnother property suggested is the wrapping of thethermoplastic .The yarn such as nylon around thethermoplastic .The yarn such as nylon around the

centraicentrai thread of alginate which is remove after thethread of alginate which is remove after thethermoplastic yarn has been sat.thermoplastic yarn has been sat.

The soluble property of the alginate yarn presentThe soluble property of the alginate yarn presentunlimited possibility in the deunlimited possibility in the devlopmentvlopment of the newof the newfabrics and new design.fabrics and new design.


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DEWATERING THE ALGINIC ACIDDEWATERING THE ALGINIC ACID

The chief advantage of this calcium alginate process is thatwater can be squeezed from the resulting fibrous alginic acid

with relative ease. (This is in contrast to the gel type of alginic

acid which results from addition of acid to sodium alginate

solution, in the alginic acid process). A screw press, such as the

Ritz horizontal continuous S-Press, is often suitable for this

squeezing and dewatering. The alginic acid is fed into the

rotating graduated-pitch screw and it is compressed by the

screw and fixed resistor bars; a screened cone at the end, which

rotates at a different speed from the screw, completes the

compression and ensures adequate discharge of solids from the

press. The dewatered product should contain at least 25%solids if it is to be used in the paste conversion of the next

step.

PHYSICAL FACTORSPHYSICAL FACTORS

When powders of soluble alginates are wettedWhen powders of soluble alginates are wetted

with water, the hydration of particles results inwith water, the hydration of particles results in

each having a tacky surface. Unless someeach having a tacky surface. Unless some

precautions are taken, the particles will rapidlyprecautions are taken, the particles will rapidly

stick together resulting in clumps which are verystick together resulting in clumps which are very

slow to completely hydrate and dissolve. Particleslow to completely hydrate and dissolve. Particle

size and type affect solubilitysize and type affect solubility behaviourbehaviour


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The quantity of the soluble alginates whichThe quantity of the soluble alginates whichwill dissolve in water is limited by the physicalwill dissolve in water is limited by the physical

nature of the solutions rather than actualnature of the solutions rather than actual

solubility. As the concentration of alginatesolubility. As the concentration of alginate

increases the solution passes through stages of aincreases the solution passes through stages of a

viscous liquid to a thick paste; at this point itviscous liquid to a thick paste; at this point it

becomes very difficult to disperse furtherbecomes very difficult to disperse further

alginate successfully.alginate successfully.

MOLECULAR WEIGHTMOLECULAR WEIGHTThe higher the molecular weight of a soluble

alginate, the greater the viscosity of its

solution. Manufacturers can control the

molecular weight (degree of polymerization,

DP) by varying the severity of the extraction

conditions and they offer products ranging

from 10-1 000 mPa.s (1% solution) with a DP

range of 100-1 000 units. Sodium alginate ofviscosity 200-400 mPa.s, "medium viscosity",

probably finds the widest application.


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TEMPERATURETEMPERATURE

Viscosity decreases as temperature increases, at a rate of

about 2.5% per degree Celsius (Figure 7). Viscosity

usually returns to a little less than the original value on

cooling. However if alginate solutions are kept above

50C for several hours, de polymerization may occur

giving a permanent loss of viscosity.

Alginate solutions can be frozen and thawed without

change of viscosity, as long as they are free of calcium

(less than 0.5%); if calcium is present the viscosity will

increase and a gel may even form and these changes will

not reverse.

USESUSES

Textile PrintingTextile Printing

Textile printing ,alginate are used as thickeners for the pasteTextile printing ,alginate are used as thickeners for the pastecontaining the dye. These pastes may be applied to thecontaining the dye. These pastes may be applied to thefabric by either screen or roller printing equipment.fabric by either screen or roller printing equipment.

FoodFood

Based mainly on their thickening ,gelling ,syrup &Based mainly on their thickening ,gelling ,syrup &toppings for ice creamtoppings for ice cream

It reduce moisture retention by the pastry.It reduce moisture retention by the pastry.


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UsesUses

PharmaceuticalPharmaceuticalAlginicAlginic acid is insoluble in water but swellsacid is insoluble in water but swells

when placed in water. This property make itwhen placed in water. This property make it

a useful disintegrating agent in tablet.a useful disintegrating agent in tablet.

WeldingWelding

Welding rods or electrodes to act as a flux andWelding rods or electrodes to act as a flux and

to control the condition in the immediateto control the condition in the immediatevicinity of the weld, such as temperature orvicinity of the weld, such as temperature or

oxygen and hydrogen availabilityoxygen and hydrogen availability

BleachingBleaching

Depending on the seaweed used as raw material, it giveDepending on the seaweed used as raw material, it give

pale color of the final productpale color of the final product

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Alginate Fiber