PMID- 15903962
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20050607
LR  - 20050520
IS  - 0031-9007 (Print)
IS  - 0031-9007 (Linking)
VI  - 94
IP  - 12
DP  - 2005 Apr 1
TI  - Chain entanglement in thin freestanding polymer films.
PG  - 127801
AB  - When a thin glassy film is strained uniaxially, a shear deformation zone (SDZ) 
      can be observed. The ratio of the thickness of the SDZ to that of the undeformed 
      film is related to the maximum extension ratio, lambda, which depends on the 
      entanglement molecular weight, M(e). We have measured lambda as a function of 
      film thickness in strained freestanding films of polystyrene as a probe of M(e) 
      in confinement. It is found that thin films stretch further than thick films 
      before failure, consistent with the interpretation that polymers in thin films 
      are less entangled than bulk polymers, thus the effective value of M(e) in thin 
      films is significantly larger than that of the bulk. Our results are well 
      described by a conceptually simple model based on the probability of finding 
      intermolecular entanglements near an interface.
FAU - Si, Lun
AU  - Si L
AD  - Department of Physics & Astronomy and the Brockhouse Institute for Materials 
      Research, McMaster University, Hamilton, ON, Canada.
FAU - Massa, Michael V
AU  - Massa MV
FAU - Dalnoki-Veress, Kari
AU  - Dalnoki-Veress K
FAU - Brown, Hugh R
AU  - Brown HR
FAU - Jones, Richard A L
AU  - Jones RA
LA  - eng
PT  - Journal Article
DEP - 20050401
PL  - United States
TA  - Phys Rev Lett
JT  - Physical review letters
JID - 0401141
EDAT- 2005/05/21 09:00
MHDA- 2005/05/21 09:01
CRDT- 2005/05/21 09:00
PHST- 2004/07/16 00:00 [received]
PHST- 2005/05/21 09:00 [pubmed]
PHST- 2005/05/21 09:01 [medline]
PHST- 2005/05/21 09:00 [entrez]
AID - 10.1103/PhysRevLett.94.127801 [doi]
PST - ppublish
SO  - Phys Rev Lett. 2005 Apr 1;94(12):127801. doi: 10.1103/PhysRevLett.94.127801. Epub 
      2005 Apr 1.