Chemistry Investigatory

7/21/2019 Chemistry Investigatory

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CONTENTS

1. Acknowledgement2. Why I Chose This Project!. Introd"ction#. $istory o% Adhesi&es'. Ch(r(cteristics o% Adhesi&es

). Cl(ssi*c(tion o% Adhesi&es+. Theory o% Adhesion,. Adsor-tion. Ty-es o% (dsor-tion1/. Ch(r(cteristics o% Adsor-tion

11. Adsor-tion (nd A0sor-tion12. (ctors (ecting A0sor-tion1!. E3-eriment

1#. 4i0liogr(-hy

WHY I CHOSE THIS PROJECT?



The role -l(yed 0y colloid(l (nd s"r%(ce

chemistry which we see in e&eryd(y li%e is

d"e to s"r%(ce -henomenon.

The (ttr(ction 0etween

s"r%(ces o% two m(teri(ls c(n 0e rel(ted

to their strong (dhesion. This (ttr(cti&e

(dhesion is ( direct res"lt o% the

(dsor-tion e3isting 0etween the s"r%(ces

in cont(ct.

5re(ter the s"r%(ce (ttr(ction6

stronger is the (dhesion. There%ore

st"dying (dsor-tion "ltim(tely -ro&ides

e3-l(n(tion %or (dhesion (ction. So I

chose to do ( -roject connecting thesetwo to-ics 0y -re-(ring (n (dhesi&e (nd

st"dying its -ro-erties.



INTRODUCTION

Adhesi&es (re s"0st(nces which (rec(-(0le o% holding m(teri(ls together in (

%"nction(l m(nner 0y s"r%(ce (tt(chment

th(t resists se-(r(tion. We "se (dhesi&es

in o"r li&es to ( l(rge e3tent. The term

(dhesi&es incl"de cement6 m"cil(ge6

gl"e (nd -(ste 7 terms th(t (re o%ten"sed interch(nge(0ly %or (ny org(nic

m(teri(l which %orms (n (dhesi&e 0ond.

In this the n(t"re6 c("se (nd mech(nism

o% (dhesion is st"died (nd (n (dhesi&e is

-re-(red.



HISTORY OF ADHESIVES

The *rst synthetic (dhesi&e w(s -rod"ced in

1,). This m(teri(l w(s incorrectly termed

nitrocell"lose (nd w(s cre(ted 0y ( re(ction

0etween nitric (cid6 s"l%"ric (cid6 (nd cell"lose.

Tod(y6 this -rod"ct is known (s cell"lose nitr(te.

In 1126 8eo 4(ekel(nd -rod"ced -henol9

%orm(ldehyde resins6 ( 0(sic m(teri(l %or m(ny o%

tod(y:s (dhesi&es. $igh strength6 el(stomeric

(dhesi&es were (&(il(0le in 12, when ( re(ction

th(t -rod"ced -olychloro-rene w(s de&elo-ed.

8(ter in the 1!/s6 -ress"re sensiti&e t(-es were

de&elo-ed.

The *rst met(l 0onding (dhesi&e w(s de&elo-ed0y Nichol(s de 4r"yne in 1#1. This m(teri(l w(s

"sed in the constr"ction o% (ircr(%t. 8(ter in the

dec(de6 e-o3y resin (dhesi&es were introd"ced.

;"ring the 1)/s the e3tremely strong

cy(no(cryl(te (dhesi&es were de&elo-ed. These

-rod"cts6 c(lled s"-er gl"es6 0ec(me (dhesi&e

when e3-osed to moist"re in the (ir. Other

(dhesi&es th(t were de&elo-ed d"ring this time

incl"de silicones (nd (n(ero0ic (dhesi&es. Since

th(t time6 most o% the (d&(nces in (dhesi&e



technology h(&e 0een the res"lt o% %orm"l(tion

modi*c(tions "sing &(ried -olymers. In the l(te

1,/s Post9It< notes were introd"ced "sing (

micro str"ct"red (dhesi&e.

CHARACTERISTICS OF ADHESIVES

or ( m(teri(l to 0e ( good (dhesi&e it

m"st h(s ( &(riety o% ch(r(cteristics.

It sho"ld h(&e ( li="id s"r%(ce tension

th(t is lower th(n the wetting

tension o% the s"0str(te. It sho"ld 0e (--lied to ( s"r%(ce th(t is

signi*c(ntly ro"gh to im-ro&e(dhesion.

or -olymeric s"0str(tes6 the (dhesi&e

sho"ld 0e somewh(t m"t"(lly sol"0le

(llowing di"sion 0etween the two to

occ"r.



CLASSIFICATION OF ADHESIVES

Adhesi&es c(n 0e cl(ssi*ed 0y the ty-e o% deli&ery

o% the (dhesi&e or 0y the -olymer "sed in the

(dhesi&e. In gener(l6 there (re *&e c(tegories o%

(dhesi&es incl"ding str"ct"r(l6 n(t"r(l6 -ress"re9

sensiti&e6 hot melt6 (nd sol&ent90(sed (dhesi&es.

> Str"ct"r(l (dhesi&es

Str"ct"r(l (dhesi&es (re some o% the strongest

(dhesi&e m(teri(ls (&(il(0le. They (re 0(sed on

resin systems6 ty-ic(lly thermosets6 (nd (re me(nt

to ser&e (s -erm(nent 0onds. They (re s"--lied (s

low9molec"l(r9weight -olymers th(t solidi%y when

-olymeri?ed. They (re sold in ( &(riety o% %ormsincl"ding two9-(rt systems6 -(stes6 (nd *lms.

E3(m-les o% Str"ct"r(l Adhesi&es



(. E-o3y resins@

E-o3y resins (re ty-ic(lly 0(sed on the

-olymeri?(tion re(ction o% 0is-henol A with

e-ichlorohydrin. The -rod"ct is sold (s ( two9-(rtsystem in which the "ser (--lies the e-o3y resin6

then (n (mine h(rdener th(t c("ses the resin to

c"re. E-o3y resins (re "sed in the constr"ction o%

(ircr(%t (nd ("tomo0iles. They (re (lso (

com-onent o% -l(stic cement.

0. Phenolic resins@

Phenolic resins h(&e 0een "sed (s (dhesi&es

since the e(rly 1//s. They (re -rod"ced 0y the

-olymeri?(tion re(ction o% -henol (nd

%orm(ldehyde. To c"re6 he(t is ty-ic(lly re="ired

to dri&e o e3cess sol&ent. This ty-e o% (dhesi&eis "sed in the -rod"ction o% -lywood. They (lso

(re noted (s the most (dhesi&e m(teri(l to

(l"min"m.

c. Acrylic (dhesi&es@

A &(riety o% (crylic (dhesi&es (re (&(il(0le.

An(ero0ic (dhesi&es (re "ni="e re(cti&e

(dhesi&es. They consist o% ( mi3t"re o% hydro

-ero3ides (nd dimeth(cryl(tes th(t -olymeri?e



in the (0sence o% o3ygen. This ty-e o% m(teri(l

is "se%"l in (nchoring screws (nd 0olts. This

(dhesi&e is 0(sed on cy(no(cryl(tes which

s-ont(neo"sly -olymeri?es in moist (ir.

d. $igh9tem-er(t"re resist(nt (dhesi&es@

(ny str"ct"r(l (dhesi&es th(t (re "sed %or

(eros-(ce -"r-oses (re lightweight (nd high9

tem-er(t"re resist(nt. These (re ty-ic(lly resinsth(t h(&e high gl(ss9tr(nsition tem-er(t"res. An

e3(m-le o% this ty-e o% (dhesi&e is -olyimide

th(t is %ormed 0y the -olymeri?(tion re(ction o%

(n (rom(tic (mine with (n (rom(tic (nhydride.

e. El(stomeric Adhesi&es@Since m(ny o% the str"ct"r(l (dhesi&es 0ecome

0rittle (%ter they c"re6 (dhesi&es %orm"l(tors

de&elo-ed el(stomeric (dhesi&es. These

m(teri(ls cont(in com-o"nds th(t red"ce

0rittleness witho"t signi*c(ntly red"cing

(dhesion. This -ro-erty is "se%"l in (--lic(tionswhere &i0r(tion(l %orces c(n stress (dhesi&es.

%. Breth(ne (dhesi&es@



The *n(l cl(ss o% str"ct"r(l (dhesi&es is the

"reth(nes. These m(teri(ls (re 0(sed on the

-olymeri?(tion re(ction o% ( diol with (

diisocy(n(te. They (re -rim(rily sold (s two9-(rtstr"ct"r(l (dhesi&es. An im-ort(nt (--lic(tion o%

these kinds o% (dhesi&es is in the ("tomoti&e

ind"stry. Poly"reth(nes (re "sed to

0ond -olyester cords in r"00er tires.

> N(t"r(l94(sed Adhesi&es@

(ny n(t"r(l90(sed (dhesi&es (re (&(il(0le. In

gener(l6 these (dhesi&es (re not (s strong (s

the synthetic (dhesi&es. N(t"r(l r"00er h(s

0een "sed (s (n (dhesi&e %or o&er 1// ye(rs. In1,2'6 the (cintosh r(inco(t6 which consisted o%

two l(yers o% cotton 0onded 0y ( l(yer o% n(t"r(l

r"00er6 w(s introd"ced. Protein (dhesi&es (re

"sed (s str"ct"r(l (dhesi&es. They (re 0(sed on

-oly(mino (cids o0t(ined %rom &(rio"s (nim(l

(nd -l(nt so"rces. C"ring is ty-ic(lly de-endent

on he(t. St(rch90(sed (dhesi&es (re deri&ed%rom -l(nts. They (re -rim(rily "sed %or 0inding

-(-er (nd (s en&elo-e (dhesi&es. Cell"lose is

(nother n(t"r(l m(teri(l th(t -ro&ides (de="(te



(dhesion. Cell"lose nitr(te w(s one o% the *rst

modi*ed (dhesi&es -rod"ced. It is ( gener(l (ll9

-"r-ose (dhesi&e which is w(ter-roo% (nd

e3i0le. odi*ed methylcell"lose is "sed tom(ke w(ll-(-er -(ste. Other n(t"r(l (dhesi&es

(re t(riDng resins th(t (re deri&ed %rom co(l6

-etrole"m or wood t(r.

> Press"re sensiti&e (dhesi&es@

Press"re sensiti&e (dhesi&es (re -olymeric9

0(sed (dhesi&es th(t melt (t room tem-er(t"re.

When -ress"re is (--lied to the (dhesi&e6 they

0ecome ow (0le there0y co&ering the

s"0str(te. As the -ress"re is remo&ed (dhesion

t(kes -l(ce. (ny t(-es "se this kind o%

(dhesi&e m(teri(l. Press"re9sensiti&e t(-e "ses( 0lend o% glycerol (nd (0iotic (cid esters with

n(t"r(l r"00er on cello-h(ne. In (ddition to

-ress"re9sensiti&e (dhesi&es6 hot melt

(dhesi&es h(&e 0een de&elo-ed. Since

thermo-l(stics melt when he(ted (nd re%orm

when cooled6 they m(ke good (dhesi&es. This isthe -rinci-le 0ehind gl"e g"ns. Nylon -olymers

(re o%ten "sed %or their %orm"l(tion.



> Sol&ent90(sed (dhesi&es@

Sol&ent90(sed (dhesi&es work thro"gh the

(ction o% the s"0str(te or (dhesi&e. The m(teri(l

is -"t on the s"0str(te (nd when the sol&ent

e&(-or(tes 0onding occ"rs. Adhesion is (ided i%

the sol&ent inter(cts with the s"0str(te. An

e3(m-le is model (ir-l(ne gl"e th(t tends to

dissol&e some o% the -l(stic. This hel-s to cre(te

( solid weld. 8(te3 (dhesi&es (re (nother ty-e

o% sol&ent90(sed (dhesi&e. They (re -olymericm(teri(ls th(t -ro&ide (dhesion (%ter their

(="eo"s sol&ent e&(-or(tes. These (re the

s(me ty-es o% -olymers th(t (re "sed %or l(te3

-(ints. 8(te3 (dhesi&es (re "sed %or 0onding

-ile to c(r-ets.

THEORY OF ADHESION

A &(riety o% theories (0o"t how (dhesi&es work

h(&e 0een -ro-osed. While none o% these

s(tis%(ctorily descri0es (ll (s-ects o% (dhesion6

they do (ttem-t to e3-l(in o0ser&ed

-henomen(. The le(ding theories o% (dhesion



incl"de the di"sion6 electrost(tic6 s"r%(ce

energetics6 (nd mech(nic(l (nd (dsor-tion

theories.

> ;i"sion theory@

The di"sion theory st(tes th(t (dhesion is (

res"lt o% the sol"0ility o% the (dhesi&e to the

s"0str(te. When the (dhesi&e is (--lied to the

s"0str(te6 it is s"ggested th(t ( sol"tion o% thes"0str(te (nd (dhesi&e is %ormed i% the sol"0ility

ch(r(cteristics (re e="(l. This cre(tes ( st(0le

-h(se th(t 0onds the two s"r%(ces together.

While this theory -ro&ides some insights6 it is

mostly (--lic(0le to sit"(tions in which

-olymers (dhere to e(ch other. It is not

(--lic(0le to systems where the s"0str(te (nd(dhesi&e (re r(dic(lly dissimil(r.

> Electrost(tic theory@

The electrost(tic theory s"ggests th(t (dhesionis the res"lt o% dierences in the electro

neg(ti&ities o% (dhering m(teri(ls. According to

the theory6 when two m(teri(ls (re 0ro"ght into



cont(ct there is (n (mo"nt o% electron tr(ns%er

th(t occ"rs. This res"lts in ( ch(rge l(yer 0eing

%ormed which c("ses the m(teri(ls to st(y

together. An e3(m-le o% this theory c(n 0e seenwhen "sing st(tic electricity to m(ke ( 0(lloon

stick to ( w(ll.

> S"r%(ce energetics theory@

The s"r%(ce energetics theory descri0es(dhesion in terms o% intermolec"l(r (nd

inter(tomic %orces. or these %orces to h(&e (n

eect6 the (dhesi&e m"st come into close

cont(ct with the s"0str(te. According to this

theory (dhesion is ( res"lt o% 0onding (cross the

inter%(ce. An e3(m-le o% this theory is chemic(l

(dhesion th(t occ"rs when the chemic(l gro"-s%rom the (dhesi&e co&(lently 0ond with those o%

the s"0str(te. Second(ry (dhesion occ"rs

simil(rly thro"gh hydrogen 0onding.

> ech(nic(l theory@



The mech(nic(l theory descri0es (dhesion in

terms o% ( -hysic(l interlocking o% the (dhesi&e

with the s"0str(te. ech(nic(l (dhesion occ"rs

when the (dhesi&e m(teri(l ows into (nd onthe microsco-ic(lly ro"gh s"0str(te s"r%(ce.

This cre(tes ( lock (nd key eect. The &iscosity

o% thie&e (nd the cont(ct time with the

s"0str(te (re im-ort(nt -(r(meters %or

mech(nic(l (dhesion. iscosity (dhesion occ"rs

0y restricted mo&ement d"e to the &isco"sn(t"re o% the s"0str(tes.

> Adsor-tion theory@

Another theory reg(rding (dhesion is the

(dsor-tion theory. This is 0y %(r the most

im-ort(nt theory reg(rding (dhesion. The-rocess o% (dsor-tion is disc"ssed in det(il.

ADSORPTION

There (re resid"(l %orces (cting (long the

s"r%(ce o% the li="id. This is (lso e3-ected %or

the s"r%(ce o% ( solid. ;"e to resid"(l %orces6 the

s"r%(ce o% ( solid For ( li="idG h(s ( tendency to



(ttr(ct (nd ret(in molec"les o% other s-ecies

with which it is 0ro"ght cont(ct. This (ttr(ction

o% -(rticles on the s"r%(ce red"ces the s"r%(ce

energy (nd hence 0rings st(0ility to the s"r%(ce. This is done 0y ( s"r%(ce -henomenon known (s

(dsor-tion.

“ The phenomenon of higher concentration of

any molecular species at the surface than in the

bulk of a solid (or a liquid) is known asadsorption. “

Some e3(m-les (re@

Ch(rco(l when mi3ed with ( colo"red

sol"tion o% s"g(r6 (dsor0s the colo"ring

m(tter (nd is "sed (s ( decolo"riser.When ( hot cr"ci0le is cooled in (tmos-here6

( *lm o% moist"re collects (t the s"r%(ce.

This is ( c(se o% (dsor-tion o% w(ter &(-o"r

on the m(teri(l o% the cr"ci0le.

THPES O A;SOPTION;e-ending on the n(t"re o% (ttr(cti&e %orces

in&ol&ed 0etween (dsor0ent (nd (dsor0(te6

(dsor-tion c(n 0e@



> Physic(l (dsor-tionJ Physisor-tion

In which (dsor0(te is held to the (dsor0ent 0y

we(k %orces s"ch (s &(n der W((ls %orces o%

(ttr(ction.

> Chemic(l (dsor-tionJ Chemisor-tion

In which (dsor0(te is held to the (dsor0ent 0y

%orces ne(rly (s strong (s ( chemic(l 0ond.

PHYSICAL ADSORPTION CHEMICAL ADSORPTION

e&ersi0le. Irre&ersi0le.

orm(tion o% m"ltimolec"l(r

l(yers.

orm(tion o% "nimolec"l(r

l(yer.

The e3tent o% (dsor-tion isrel(ted to the e(se o%

li="e%(ction o% the g(s.

No correl(tion e3ists.

orces o% (ttr(ction 0etween

(dsor0(te (nd (dsor0ent (re

we(k F&(n der W((lsK %orcesG.

orces o% (ttr(ction (re

strong F(s ( chemic(l

0ondG.

Non9s-eci*c in n(t"re. $ighly s-eci*c.8ow he(t o% (dsor-tion @ 2/9 #/

kLJmol. $igh he(t o% (dsor-tion @

'/9 #// kLJmol.



Occ"rs (t low tem-er(t"re (nd

decre(ses with incre(sing

tem-er(t"re.

Occ"rs (t higher

tem-er(t"re6 e3tent o%

(dsor-tion *rst incre(ses

(nd then decre(ses withincre(se in tem-er(t"re.

A compariso !"#$"" #%" #&p"s o'

a(sorp#io

CHARACTERISTICS OF

ADSORPTION

> Solids6 -(rtic"l(rly when *nely di&ided6 h(&e

( l(rge s"r%(ce (re(6 hence this 0eh(&ior is

-redomin(ntly on solid s"r%(ces.

> The solid th(t t(kes "- ( g(s or &(-o"r or (

sol"te %rom sol"tion6 is c(lled (dsor0ent while

the g(s or the sol"te6 which is held to the

s"r%(ce o% the solid is c(lled (dsor0(te.

> The remo&(l o% (dsor0ed s"0st(nce %rom (

s"r%(ce is c(lled desor-tion .When e="ili0ri"m is

re(ched

(te o% (dsor-tion M (te o% desor-tion.



> In some c(ses6 (dsor-tion (nd (0sor-tion

t(ke -l(ce sim"lt(neo"sly (nd it is diDc"lt to

determine the rel(ti&e e3tent o% (dsor-tion (nd

(0sor-tion. The term sor-tion is widely is "sed

in s"ch c(ses.

ADSORPTION AND A)SORPTION

Adsor-tion is dierent %rom (0sor-tion.

A0sor-tion o% ( s"0st(nce A 0y ( s"0st(nce 4

me(ns th(t A is "ni%ormly distri0"ted (ll o&er 4.

Adsor-tion on the other h(nd6 me(ns th(t A is

-resent on the s"r%(ce o% 46 0"t the

concentr(tion o% A in -(rts o% 4 %rom the s"r%(ce

is negligi0le.



EAP8ES

W(ter &(-o"r is (0sor0ed 0y (nhydro"s

c(lci"m chloride while it is (dsor0ed 0y silic(gel.

Ammoni( is (0sor0ed 0y w(ter6 0"t it is

(dsor0ed 0y ch(rco(l.

ADSORPTION A)SORPTION

It is ( s"r%(ce

-henomenon.

It is ( 0"lk

-henomenon.

Adsor0(te is

(cc"m"l(ted (t

the s"r%(ce.

The s"0st(nce

getting (dsor0ed

thro"gho"t the 0"lk

o% the s"0st(nce.

The r(te o% (dsor-tion is

&eryr(-id in the 0eginning.

The

r(te howe&er decre(ses

gr(d"(lly "ntil

e="ili0ri"m is re(ched.

Adsor-tion -roceeds

(t ( ste(dy r(te.



FACTORS AFFECTIN* ADSORPTION

The %(ctors (ecting (dsor-tion (re gi&en 0elow

in det(il@

> Na#+r" o' a(sor!a#", The r(te (nd

s-eci*city o% (dsor-tion de-ends on the m(teri(l

0eing (dsor0ed. or e3(m-le r(tes o% (dsor-tiono% g(ses s"ch (s N$! is dierent %rom g(ses

s"ch $2

> Na#+r" o' #%" a(sor!"#, E(ch o% the

(dsor0ents h(s dierent s"r%(ce (nd hence

dierent ch(r(cteristic (dsor0ent -ro-erties.

> Sp"ci-c ar"a o' #%"

a(sor!"#, Adsor-tion on ( s"r%(ce is directly

-ro-ortion(l to the s"r%(ce (re( o% the

(dsor0ent.

> E."c# o' #"mp"ra#+r", Adsor-tion is

gener(lly tem-er(t"re de-endent. or



e3othermic -rocess (dsor-tion decre(ses with

incre(se in tem-er(t"re (nd &ice &ers( %or

endothermic -rocess.

> Pr"ss+r" o' #%" /as 0 A(sorp#io

iso#%"rms, The e3tent o% (dsor-tion o% the g(s

on ( solid s"r%(ce de-ends on its -ress"re (s

gi&en 0y re"ndlich (nd 8(ngm"ir (dsor-tion

isotherms.

12 Fr"+(3ic% a(sorp#io iso#%"rm,

In c(se o% (dsor-tion o% g(ses on solids6 the

rel(tion 0etween 3Jm (nd -ress"re - o% the g(s

(t const(nt tem-er(t"re is gi&en 0y thee="(tion@

45m 6 7p15 891:

where k (nd n (re -(r(meters o%the e="(tion de-ending "-on the n(t"re o% the

g(s (nd the solid. 3Jm is the n"m0er o% moles o%

(dsor0(te di&ided 0y the m(ss o% the (dsor0ent.



Pr"ss+r"

re"ndlich (dsor-tion isotherm howe&er %(ils (t

higher tem-er(t"re (nd is "ns"it(0le %or

monol(yer chemisor-tion.

;2 La/m+ir a(sorp#io iso#%"rm,

8(ngm"ir deri&ed (n (dsor-tion isotherm on

theoretic(l consider(tions 0(sed on kinetictheory o% g(ses. This isotherm is 0(sed on the

(ss"m-tion th(t e&ery (dsor-tion site is

e="i&(lent (nd th(t the (0ility o% ( -(rticle to

0ind there is inde-endent o% whether or not

ne(r0y sites (re occ"-ied.

The 8(ngm"ir (dsor-tion isotherm is

re-resented 0y the rel(tion

45m68ap51<!p:

where ( (nd 0 (re two 8(ngm"ir-(r(meters. At &ery high -ress"re6 the (0o&e

isotherm (c="ires the limiting %orm



45m6a5! 8a# ="r& %i/% pr"ss+r":

45m6ap 8a# ="r& 3o$ pr"ss+r":

Pr"ss+r" @

The 8(ngm"ir (dsor-tion isotherm is gener(lly

more s"ccess%"l in inter-reting the d(t( th(n the

re"ndlich isotherm when ( monol(yer is %ormed

i.e. in c(se o% chemisor-tion.

E>PERIMENT

AIM,



To -re-(re (dhesi&es %rom -etrol (nd

thermocole.

APPARATUS REUIRED,

5l(ss rod6 Petrol6 Thermocole6 4e(ker.

CONDITIONS,

The e3-eriment w(s c(rried (t norm(l room

tem-er(t"re (nd -ress"re.

PROCEDURE,

The -roced"re is (s %ollows

I. T(ke '/ ml o% -etrol "sing ( 0"rette in (

cle(n (nd dry 5l(ss 0e(ker.II. Now t(ke the thermocole which h(s 0een c"t

into sm(ll Pieces (nd (dd slowly to -etrol in

the 0e(ker.III. Stir contin"o"sly (nd kee- on (dding

thermocole into the 0e(ker.I. A%ter ( while no more thermocole dissol&es

in the -etrol.. Sto- (dding thermocole (nd (llow it to st(nd

%or ( %ew min"tes.

O)SERVATION,



The 0e(ker cont(ining -etrol now h(s ( thick

(nd co(g"l(ted m(ss in it. This is the res"lt(nt

(dhesi&e.

E>PERIMENTAL MECHANISM,

Thermocole is 0(sic(lly -olystyrene FC$FC)$'G 7

C$2Gn

0y str"ct"re. Petrol is chemic(lly ( mi3t"re o%

hydroc(r0ons. When thermocole is (dded to

-etrol6 -etrol (cts (s ( sol&ent (nd dissol&es

thermocole. When -etrol is s(t"r(ted with

thermocole we get ( co(g"l(ted m(ss which is

the (dhesi&e. When we (--ly this (dhesi&e to (

s"r%(ce6 molec"les o% the (dhesi&e get (dsor0edon the s"r%(ce. When we -l(ce (nother s"r%(ce

on the *rst one6 these two s"r%(ces stick

together (s the (dhesi&e molec"les 0ind to the

second (s well. Th"s strong (dhesi&e (ttr(ction

w(s %ormed 0etween the two s"r%(ces d"e to

strong (dsor-tion.



TESTS FOR ADHESION,

The (0o&e (dhesi&e w(s tested 0y (--lying it to

&(rio"s (rticles. It w(s %o"nd to %orm ( strong

(nd e3cellent (dhesi&e 0ond 0etween &(rieties

o% (rticles s"ch (s wood6 -l(stic6 -(-er etc. A

gr(-h w(s -lotted to show the e3tent o%(dhesion o% dierent s"r%(ces.

It w(s %o"nd th(t the e3tent o% (dhesion w(s

m(3im"m %or wood (nd minim"m %or gl(ss. Th"s

this (dhesi&e w(s %o"nd to 0e most s"it(0le %or

"s(ge on wooden (rticles.

RESULT,

Th"s (n (dhesi&e w(s -re-(red %rom thermocole

(nd -etrol.



)I)LIO*RAPHY

1. www.(sk.com2. www.google.com

!. www.wiki-edi(.com#. www.howst"works.com'. Physic(l Chemistry 0y W(lter. L.

oor.). NCET Cl(ss 12 Chemistry

Te3t0ook+. S(r(sw(ti Chemistry Pr(ctic(l 4ook

http://www.ask.com/

http://www.google.com/

http://www.wikipedia.com/

http://www.howstuffworks.com/

http://www.google.com/

http://www.wikipedia.com/

http://www.howstuffworks.com/

http://www.ask.com/

Chemistry Investigatory

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