1. 열가소성 폴리우레탄 탄성체의 구조와 물성 (강의 자료 5)
열가소성 폴리우레탄 탄성체의 구조와 물성 (강의 자료 5)
울산대학교 화학과
정 한 모

2. 1.
1.1.

4. 1.2.

5. · improved low temperature flexibility
2. TPU의 구조와 물성
1) General
· phase segregation ↑
· effective crosslinking and filler → modulus↑
· crystallinity of hard segment phase↑ → modulus↑
high temperature property↑
· improved low temperature flexibility
∙ crystallization of soft segment phase↑ → elasticity↑
permanent set↑
cold hardening↑

6. ∙ MDI + polyester type soft segment(hard segment about 40%)
Fig. 2. Plot of Young’s modulus E as a function of time following
annealing at 170℃ for 5min.
* E increases rapidly over a period of about 3hr

7. ∙ dramatic increase in Young’s modulus (dependent on structure).
Fig. 11. Schematic representation of degrees of hard segment domain
order.(Broad line, hard segment ; thin line, soft segment. Distribution
of hard segment lengths is based on the most probable distribution with
an average length of six units.) (A) Lesser ordered, non-crystalline
hard segment domains ; (B) greater ordered, non-crystalline hard
segment domains ; (C) microcrystalline hard segment domains.
∙ dramatic increase in Young’s modulus (dependent on structure).

8. ∙ the study of thermal transition is important to the understanding
2) Thermal analysis by DSC
∙ the study of thermal transition is important to the understanding
of morphology and intermolecular bonding
Fig. 4. Typical DSC thermogram of PU elastomer.
∙ phase segration↑ : Tgs↓, Tgh↑, Tms↑, Tmh↑
crystallinity of each phase↑
∆Cps의 감소 정도↓
∙ Tccs-Tgs↓, Tms-Tmcs↓,Tmh-Tmch↓ : crystallization rate of
corresponding segment↑

9. 3) FT- IR Analysis νNH,free : 3445 cm-1 νNH,bonded : 3305-3320 cm-1
Fig. 6. IR spectrum of PU(PTMG-MDI-ED(ethylene diamine))
(number mean hard segment content)
νNH,free : 3445 cm νNH,bonded : cm-1
νCO,free,UT : cm-1 νCO, bonded, UT : cm-1
νCO,free,UA : 1695 cm νCO, bonded, UA : cm-1

10. ∙ Phase segregation kinetics by IR
(W.J.Macknight, et.al., Macromolecules, 21, 270(1988))
(PPG+MDI+BD)
Fig. 7. Changes observed as a function of time for the C=O
stretching region(1700 cm-1) : (a) 10℃, (b) 20℃

11. 4) 연신에 의한 Morphology 변화 domain orientation phase mixing
Fig. 47. Morphological model for domain structure in extended
polyurethane elastomer: a)structure at 200% elongation,
b)structure at 500% elongation.
domain orientation
phase mixing
segment orientation
(M.Shibayama, et.al., Polym.J., 18, 719 (1986)
″ ″ , ″ , 21, 895(1989))

12. 5) Soft segment
(C.S.Paik Sung, et. al., Macromolecules, 13, 111(1980))
Fig. 26. Comparison of Tg of the soft segment phase in
polyether poly(urethanes) and poly(urethaneureas).
Fig. 27. Comparison of Tg of the soft segment phase in
polyester poly(urethanes) and poly(urethaneureas).

13. ∙ long flexible soft segment largely controls the low
temperature properties, the solvent resistance,
and the weather resistant properties of TPU
polyester type : physical strength (more polar,
greater tendency to undergo
crystallization on extension)
solvent and chemical resistance
polyether type : flexibility
hydrolytic stability
superior low-temperature properties
PTMG can crystallize upon extension
∙ molecular weight↑ phase segregation↑

14. Table 4. ∆Cp Values of Pure Soft Segments and Phase in Polyurethane
a ∆Cp1 for initial oligomers.
b ∆Cp2/gram of soft segment in MDI-butanediol polyurethanes.
c ∆Cp2/∆Cp1
(Y.Camberlin, et.al., J.Polym.Sci., Polym. Chem., 21, 415(1983))

15. 6) Diisocyanate bulky, more rigid aromatic diisocyanate with symmetry
higher in hardness and modulus
greater molecular flexibility, with a spatial separation by
a methyl side chain softer and more elastic polymer
strength and phase segregation: 2,4-TDI < 2,6-TDI
(asymmetric) (symmetric)
∙ little influence on low-temperature properties

16. TDI + BD + soft segment
(C.S Paik Sung, et. al., Polym. Eng. Sci., 17, 73 (1977))
Fig. 24. Elevation of glass transition temperature, 2,4-TDI polyurethane.
Fig. 25. Elevation of glass transition temperature, 2,6-TDI polyurethane.

17. Table 6. Mechanical properties of polyurethane
(polyol/diisocyanate/BD)
TDI, IPDI: amorphous MDI, HDI: crystalline
(M.V.Pandya, et. al., J.Appl.Polym.Sci., 32, 4959(1986))

18. 7) Chain Extender
Table 5.
∆Cp2 Values of Hydrogenated Polybutadiene Soft Phase in Polyurethanes
Based on MDI and Different Chain Extenders

19. interaction betweem hard segments↑
* Phase segregation:
aliphatic diol < aromatic diol < aliphatic diamine < aromatic diamine
interaction betweem hard segments↑
better high temperature behavior

20. ∙ minor effect in elastomer property
(S.Yamashiro, Polym.J., 45, 535(1988))
∙ minor effect in elastomer property
∙ n=2 : thermal instability at high temperature when hard segment
content is high
∙ n↑ : softer, more elastic, compression set↓
∙ no major improvement in low- temperature properties by
varying the lenght of diol from C2 to C6
∙ odd number chain extender : significant strain in hydrogen bonds
between neighboring molecules reduced stability of the
physical crosslinking
∙ optimum balance of tensile, elongation, and tear property occurs
when n=4
∙ 1,4-butane diol and hydroquinone bis(2-hydroxyethyl) ether are
the most suitable diols for thermoplastic polyurethane elastomer.
The latter gives better high and low temperature properties and
reduced comprssion set.

21. 8) Tensile properties hard segment content↑, soft segment Mn↑
Fig. 45. Stress-strain curves for the polyether polyurethaneurea.
(PEUU , hard segment 46 wt%, PTMG Mn 1000)
(PTMG + MDI + ED(ethylene diamine)
hard segment content↑, soft segment Mn↑
physical property↑

22. * upon decrease of the hard segment content, a change
Fig. 9. Schematic representation of domain structure in
segmented polyurethane ( hard blocks,
polyol soft blocks).
* upon decrease of the hard segment content, a change
of morphology from interconnecting to more isolated
hard domains take place.
* hard domain interconnectivity↑ plastic deformation
at lower strain

23. 9) Hysteresis (or Permanent set)
Fig. 46. Stress hysteresis vs. elongation curves for the polyether polyurethaneurea samples.
∙ a high level of hysteresis at small strains
from plastic deformation of semicrystalline or glassy
structure within the material and /or the disruption of
interconnected hard segment domains
∙ hard segment content↑ hard domain interconnectivity and
a higher degree of order in hard
domain hysteresis↑
∙ isolated hard domains dispersed in an amorphous soft segment
matrix hysteresis↓
∙ for PEUU : at high stress level irreversible
strain induced crystallization
∙ sample cast at high temperature crystallization of both phase↑
Young’s modulus and hysteresis↑
(main factor is crystallization of soft segment)
(J.Foks, et.al., Eur.Polym.J., 26, 309(1990))

24. 10) Molecular Weight Distribution of Hard and Soft Segment
1) ∙ narrowing of hard segment size distribution increases modulus,
tensile, and extension set dramatically
∙ narrowing of the soft segment distribution causes a slight
increase in modulus, a moderate increase in elongation and
tensile, and a large increase in extension set
(L.L.Harrell, Jr., Macromolecules, 2, 607(1969)
(G.L.Wilkes et.al., J.Appl.Polym.Sci., 29, 2695(1984))
Fig. 53. Stress-strain properties
as a function of segment
size distribution.
(BN: soft broad
hard narrow)
Fig. 54. Extension set properties

25. ∙ two step method lead to a narrower distribution of
Fig. 55. PU resin 의 사슬 구조를 도식화하여 나타낸 것.
(PTMG + MDI + BD)
∙ two step method lead to a narrower distribution of
hard segment lengths as compared with that for a one
step synthesis.

26. vs. (b) one shot: higher but broad Tmc
Fig. 56. 강온 DSC thermogram : (a)1P30N15M1, (b)1P30N15M2,
(c)1P50N15M1, (d)1P50N15M2.
vs. (b) one shot: higher but broad Tmc
two shot: lower but narrow Tmc narrow molecular
hard weight distribution
(c) vs. (d) one shot: small Tmc some long hard segment
two shot: no Tmc

27. ∙ PTMG 2000 인 경우 : one shot의 물성↑
∙ Nylon 포함된 경우 : one shot의 물성↓↓

28. 감사합니다.