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CC TRNG THI VT L CA POLYMER
TRNG I HC M - A CHT KHOA DU KH
B MN LC HA DU
CC TRNG THI VT L CA POLYMER
1.Kim Thanh H 2.Trn Thy Giang 3. Nguyn Quc Cng 4. Nguyn Minh Giang 5. Nguyn Ngc Cng
Nhm sinh vin thc hin
Gio vin hng dn : PGS.TS.BI TH L THY
NHNG TNH CHT C L C BIT CA POLYME
Nhng trng thi vt l ca polyme s gip ta hiu r hn v polyme
ngha
Ni dung
1
2
S BIN DNG CA POLYME
CC TRNG THI VT L
1 S BIN DNG CA POLYME
1# CC KHI NIM M
U
2# MT S BIN
DNG CA POLYME
1 S BIN DNG CA POLYME
1# CC KHI NIM M
U
2# MT S BIN
DNG CA POLYME
1 1# BIN DNG
L kh nng ca vt th chng li bin dng v phc hi hnh dng ban u khi tc dng
lc bn ngoi .
Phn loi
N HI Hnh dng c
phc hi hon ton.
N HI DO * ch phc hi mt
phn .
*n hi do hay cn gi l n hi nht
1
2# S BIN DNG
BIN DNG THUN NGHCH Phn t bin dang s phc hi li hnh dng ban u
khi ngng tc dng lc bn ngoi . #bin dng n hi
BIN DNG KHNG THUN NGHCH
Phn t gi nguyn c hnh dng bin dng sau khi ngng tc dung lc bn ngoi.
# cht do
3# CHT N HI
Cht kt tinh Thay i hnh dng v bin dng thun nghch khng ln. n hi ca tinh th mang bn cht nng lng.
V khi bin dng th cht c cu trc v nh hnh. Cao su Vt th ch cn mt lc nh bn ngoi tc dng c kh nng bin dng vi trm phn trm.
#nha
M un n hi : c trng cho n hi
=
F : l lc tc dng ln vt th A: Tit din ca mu .
1
4# NG SUT
E : Gi l m un n hi : Bin dng tng i.
Vt liu c bn cht nng lng th c m un n hi ln. Vt liu c bn cht ng hc th c m un nh .
S khc nhau gia hai bn cht l ph thuc vo nhit v hiu ng nhit khi bin dng
1
1 S BIN DNG CA POLYME
1# CC KHI NIM M
U
2# MT S BIN
DNG CA POLYME
1
1
MT S BIN DNG CA POLYME
2
3
4
S bin dng do v chy nht
Bin dng n hi cao
Hin tng phc hi
Hin tng tr
1 S BIN DNG DO V CHY NHT
nh ngha l trng hp c bit ca s bin dng d , tng lin tc
khi tc dng mt ng sut tip tuyn khng thay i polymer.
c im Tnh cht ca vt th rn v lng. nht ca dung dch rt cao Kh nng polyme trng ln trong khi ha tan Kh nng th hin rt mnh tnh bt ng hng
M hnh th hin tnh do ca chui polymer
1
1
MT S BIN DNG CA POLYME
2
3
4
S bin dng do v chy nht
Bin dng n hi cao
Hin tng phc hi
Hin tng tr
1 BIN DNG N HI CAO
nh ngha l s dui thng ca cc mch di gp khi c lc ngoi v
tr v trng thi khi ct lc
iu kin xut hin Phn t chui polymer cn c un do ln Tc thay i cu dng cn phi cao
1
1 1
1
MT S BIN DNG CA POLYME
2
3
4
S bin dng do v chy nht
Bin dng n hi cao
Hin tng phc hi
Hin tng tr
HIN TNG PHC HI
nh ngha Qu trnh chuyn t trng thi khng cn bng sang trng thi cn bng theo thi gian
Hin tng phc hi
Thay i chp nhong cc gc ha tr v khong cch gia cc nguyn t Vi lc v m-un n hi ln .
S dui thng ca cc phn t gp khc
c im
Ph thuc vo ng sut lc t ,vo thi gian tc dng ca lc. S hi phc ny gi l s hi phc bin dng
1 1
1
MT S BIN DNG CA POLYME
2
3
4
S bin dng do v chy nht
Bin dng n hi cao
Hin tng phc hi
Hin tng tr
HIN TNG TR
nh ngha Ngun gc t hin tng hi phc n hi cao khi c lc
tc dng v khi ct lc tc dng ln mu.
Bn cht ca hin tng
S lch nhau v bin dng thun v nghch l do s bin dng pht trin chm hn l s thay i ng sut.
Hai ng bin dng ny khng trng nhau to nn vng tr.
ln vng tr l s khc nhau ca hai din tch OMC v CMD :
S =
+
l ng sut khi tng l ng sut khi gim
2
1
Ni dung
1
2
S BIN DNG CA POLYME
CC TRNG THI VT L
CC TRNG THI VT L
1# TRNG THI T HP V TRNG THI PHA
2# TRNG THI THY TINH HA
3# TRNG THI N HI CAO
4# TRNG THI CHY NHT
5# TRNG THI KT TINH
CC TRNG THI VT L
1# TRNG THI T HP V TRNG THI PHA
2# TRNG THI THY TINH HA
3# TRNG THI N HI CAO
4# TRNG THI CHY NHT
5# TRNG THI KT TINH
TRNG THI T HP
Trng thi kh Dao ng, tim tin v quay, mt t hp nh
Trng thi rn Mt t hp cao, khong cch gia cc phn t nh, khng c s chuyn ng tim tin v quay.
Trng thi lng C tnh cht chuyn ng nh th kh v mt t hp nh th rn
*khc nhau v tnh cht chuyn ng v mt t hp
TRNG THI T HP
Trng thi kh Dao ng, tim tin v quay, mt t hp nh
Trng thi rn Mt t hp cao, khong cch gia cc phn t nh, khng c s chuyn ng tim tin v quay.
Trng thi lng C tnh cht chuyn ng nh th kh v mt t hp nh th rn
*khc nhau v tnh cht chuyn ng v mt t hp
TRNG THI PHA
nh ngha L h khc nhau v b mt phn chia, v nhng tnh cht nhit ng hc.Pha c th d tch ra khi nhau.
Phn loi Pha tinh th: c trng bng bc xa ba chiu ca s phn
b cc nguyn t hay phn t. Pha lng : khng c mng li tinh th, c mt t hp
ging nh l pha tinh th. #pha v nh hnh
Pha kh : chuyn ng hon ton hn n ca cc phn t, ngha l khng c bc no c.
TRNG THI PHA &TRNG THI T HP
GING NHAU Trng thi kh v pha kh
cng nhau. Trng thi rn tng ng
vi hai pha: tinh th v v nh hnh.
Pha lng gm hai trng thi t hp: rn* v lng*.
KHC NHAU Trng thi t hp :nng
lng tng tc v chuyn ng nhit.
Pha : tnh cht nhit ng hc, nh nng lng t do, t khi
rn * dng thy tinh lng * nhit cao hn nhit nng chy.
S CHUYN PHA
nh ngha : S chuyn t trng thi ny sang trng thi khc c lin quan n nhng thay i v hnh thi sp xp ca cc
phn t v thay i tnh cht nhit ng hc
Phn loi
Chuyn pha loi 1: Thay i nhy vt tnh cht nhit ng hc , c trng l thay i entanpy ca h. nhng chuyn pha loi ny nh l : nng chy, kt tinh, ngng t, bay hi . Chuyn pha loi 2: Khng c s thay i nhy vt m thay i t t cc tnh cht nhit ng. khng c n nhit ca s chuyn pha.
NG CONG C NHIT
nh ngha: S ph thuc bin dng vo nhit c xc nh trn my Koncistometer.
Ba vng bin dang c trng cho ba trng thi vt l khc nhau
Vng I : Thy tinh S bin dng rt nh vi ln t l vo nhit gi tr ng sut khng ln, polymer nh l vt rn ch yu tun theo nh lut Hook.
Vng II :n hi cao C s bin dng thun nghch. t thay i vi nhit v c modun n hi khng ln. Bin dng c km theo bin dng chy tng theo nhit .
Vng III : Chy nht Nhit tng lm tng s bin dng khng thun nghch Nhit chuyn t trng thi n hi cao sang chy nht l nhit trung bnh
Ph thuc vo cu trc ca polyme, khi lng phn t, nhit
Trong k thut, phng php c nhit c th dng nghin cu nh hng ca cc cht ph gia khi ng rn polyme.
CC TRNG THI VT L
1# TRNG THI T HP V TRNG THI PHA
2# TRNG THI THY TINH HA
3# TRNG THI N HI CAO
4# TRNG THI CHY NHT
5# TRNG THI KT TINH
1.c tnh ca polyme thy tinh ha
2.S bin dng n hi bt buc
Kh nng thy tinh ha T l nng lng tng tc ni v gia cc phn t vi nng lng
chuyn ng nhit ca cc mt xch polyme.
c im 1.Khi lm lnh mt cht nng chy c th tm thy tinh th hay thy tinh.
2.S chuyn cht lng thnh thy tinh khng phi l s chuyn pha.
3. Vt th thy tinh khc vi th lng : linh ng v trng thi nng lng.
Tnh cht 1.Lin quan cht ch vi un do 2.Khc polyme thy tinh thng l kh nng bin dng gim, tinh gin v n hi tng .
1.c tnh ca polyme thy tinh ha
2.S bin dng n hi bt buc
nh ngha S bin dng ln c pht trin trong trong
polyme thy tinh khi c ng sut ln. Ch xut hin di nh hng ca ng sut ln. C tnh cht thun nghch.
ng sut ti hn th l ng sut t c ln ca nng lng hot ha hay l ng sut m tc bin dng bng
tc phc hi.
Nhit gin Td :nhit m polyme thy tinh mt i kh nng bin dng ln v b ph hy ngay khi c bin dng nh.
Cc yu t ph thuc 1.Cu trc polyme. 2. phn cc : Khng phn cc :Ttt thp. Phn cc mnh :Ttt cao
CC TRNG THI VT L
1# TRNG THI T HP V TRNG THI PHA
2# TRNG THI THY TINH HA
3# TRNG THI N HI CAO
4# TRNG THI CHY NHT
5# TRNG THI KT TINH
c trng cho polyme c un do cao ca phn t. c xem l lng i vi cc mt xch v l thy tinh i vi ton
phn t. Trng thi n hi cao l trng thi khng cn bng.
iu kin xut hin 1# un do phn t polyme ln. 2# Tc thay i hinh dng ca polyme.
Yu t nh hng S thay i cu dng : dao ng hn n dng
lin kt ha hc v chuyn ch ca cc ng phn quay .
Thnh phn ha hc v cu trc phn t. Bn cht lc tng tc, bn cht phn b trt t
cc phn t v nhit .
S ph thuc bin dng n hi cao vo nhit khc nhau ( t1>t2>t3 )
*Xc nh bi s thay i ni nng v entropi i vi s bin dng.
*nng lng t do
BIN DNG N HI CAO & BIN DNG THNG
Nu bin dng chm xc nh ch yu bng thnh phn
entropi.
Nu bin dng nhanh bng
thnh phn ni nng.
CC TRNG THI VT L
1# TRNG THI T HP V TRNG THI PHA
2# TRNG THI THY TINH HA
3# TRNG THI N HI CAO
4# TRNG THI CHY NHT
5# TRNG THI KT TINH
nh ngha L s chuyn ch khng thun nghch ca cc phn t i vi nhau khi c tc dng ca lc ngoi v trong cht hnh
thnh lc ma st ni chng li s chuyn ch ca cc phn t.
Tnh cht S bin dng l khng thun nghch. Tnh chy ca polyme cng cao, mc trng hp cng
thp, nhit cng cao v lng cht thp phn t cng ln.
S chuyn ch mch polyme da trn nng lng hot ha . Nhit hot ha tnh theo s ph thuc nhit ca h s
nht:
lg = lgA +
,.
,.
C CH
c im ca s chy L chuyn ch lin tc Cc mc xch ca mch hay ca nhng phn ca mch . Chng t nhit hot ha khng ph thuc vo chiu di ca mch.
Lun km theo bin dng n hi cao Do dui thng hay gp khc mch.
Ph thuc vo nht nht li ph thuc nhiu vo chiu di mch. Xy ra vi mch un do C cu dng khc nhau ,mch cng xy ra kh khn. Nhit chy nht Ph thuc vo ch bin dng v khi lng phn t.
CC TRNG THI VT L
1# TRNG THI T HP V TRNG THI PHA
2# TRNG THI THY TINH HA
3# TRNG THI N HI CAO
4# TRNG THI CHY NHT
5# TRNG THI KT TINH
C ch qu trnh kt tinh L qu trnh hnh thnh phi (hay mm) ca pha kt tinh trong pha v nh hnh v s ln dn ca cc phi .
Qu trnh kt tinh l s chuyn pha.
Tc kt tinh L lng cht kt tinh trong mt n v thi gian.
Ph thuc vo: 1. Tc to thnh trung tm hay phi kt tinh . 2.Tc ln ca chng.
Note: S kt tinh thng khng bt u nhit nng chy m thp hn.
S kt tinh l s chuyn t bc gn ti bc xa ca cc mch v cc mc xch, ngha l s chuyn pha.Khc vi thy tinh
ha.
YU T NH HNG N KH NNG KT TINH
1 C cu trc mch iu ha ln c kh nng kt tinh Cu trc mch khng iu ha khng c kh nng kt tinh.
2
Nhm phn cc trong phn t, s nh hng d th s kt tinh cng d dng. Tng tc phn t cng ln, nht ca h cng ln tc kt tinh li gim.
3 Chuyn ng nhit ca cc mt xch hay un do mch. Lc ht cc phn t v s chuyn ng nhit ca phn t.
CC TRNG THI VT L
1# TRNG THI T HP V TRNG THI PHA
2# TRNG THI THY TINH HA
3# TRNG THI N HI CAO
4# TRNG THI CHY NHT
5# TRNG THI KT TINH
HT RI
Cm n c v cc bn lng nghe v theo di.