Positron lifetime spectroscopy characterization of thermal history effects on polycarbonate

A. J. Hill; C. M. Agrawal

doi:10.1007/BF00580127

Positron lifetime spectroscopy characterization of thermal history effects on polycarbonate

A. J. Hill, C. M. Agrawal

Orthopaedics

Research output: Contribution to journal › Article › peer-review

23 Scopus citations

Abstract

The effect of a short-term anneal above T_g on the free volume cavity size and concentration and on the fracture toughness of polycarbonate is examined. The positron annihilation lifetime (PAL) technique is used to measure the change in free volume concentration and cavity size during isothermal relaxation experiments at 10, 20 and 30 ° C. An activation energy of 16.5 kJ mol^-1 is calculated for the relaxation of the annealed polycarbonate, compared to 12.3 kJ mol^-1 for the unannealed material. The fracture toughness and brittle fracture morphology of compact tension specimens are unchanged by the anneal. The similarity in the PAL parameters and physical properties between the unannealed polycarbonate and the material annealed above T_g suggests that the short-term anneal does not appreciably alter the structural state of glassy polycarbonate.

Original language	English (US)
Pages (from-to)	5036-5042
Number of pages	7
Journal	Journal of Materials Science
Volume	25
Issue number	12
DOIs	https://doi.org/10.1007/BF00580127
State	Published - Dec 1 1990

ASJC Scopus subject areas

Materials Science(all)
Mechanics of Materials
Mechanical Engineering

Access to Document

10.1007/BF00580127

Fingerprint Dive into the research topics of 'Positron lifetime spectroscopy characterization of thermal history effects on polycarbonate'. Together they form a unique fingerprint.

Cite this

@article{c78f4218c8c048e1be62cc0f5928f3f3,

title = "Positron lifetime spectroscopy characterization of thermal history effects on polycarbonate",

abstract = "The effect of a short-term anneal above Tg on the free volume cavity size and concentration and on the fracture toughness of polycarbonate is examined. The positron annihilation lifetime (PAL) technique is used to measure the change in free volume concentration and cavity size during isothermal relaxation experiments at 10, 20 and 30 ° C. An activation energy of 16.5 kJ mol-1 is calculated for the relaxation of the annealed polycarbonate, compared to 12.3 kJ mol-1 for the unannealed material. The fracture toughness and brittle fracture morphology of compact tension specimens are unchanged by the anneal. The similarity in the PAL parameters and physical properties between the unannealed polycarbonate and the material annealed above Tg suggests that the short-term anneal does not appreciably alter the structural state of glassy polycarbonate.",

author = "Hill, {A. J.} and Agrawal, {C. M.}",

year = "1990",

month = dec,

day = "1",

doi = "10.1007/BF00580127",

language = "English (US)",

volume = "25",

pages = "5036--5042",

journal = "Journal of Materials Science",

issn = "0022-2461",

publisher = "Springer Netherlands",

number = "12",

}

TY - JOUR

T1 - Positron lifetime spectroscopy characterization of thermal history effects on polycarbonate

AU - Hill, A. J.

AU - Agrawal, C. M.

PY - 1990/12/1

Y1 - 1990/12/1

N2 - The effect of a short-term anneal above Tg on the free volume cavity size and concentration and on the fracture toughness of polycarbonate is examined. The positron annihilation lifetime (PAL) technique is used to measure the change in free volume concentration and cavity size during isothermal relaxation experiments at 10, 20 and 30 ° C. An activation energy of 16.5 kJ mol-1 is calculated for the relaxation of the annealed polycarbonate, compared to 12.3 kJ mol-1 for the unannealed material. The fracture toughness and brittle fracture morphology of compact tension specimens are unchanged by the anneal. The similarity in the PAL parameters and physical properties between the unannealed polycarbonate and the material annealed above Tg suggests that the short-term anneal does not appreciably alter the structural state of glassy polycarbonate.

AB - The effect of a short-term anneal above Tg on the free volume cavity size and concentration and on the fracture toughness of polycarbonate is examined. The positron annihilation lifetime (PAL) technique is used to measure the change in free volume concentration and cavity size during isothermal relaxation experiments at 10, 20 and 30 ° C. An activation energy of 16.5 kJ mol-1 is calculated for the relaxation of the annealed polycarbonate, compared to 12.3 kJ mol-1 for the unannealed material. The fracture toughness and brittle fracture morphology of compact tension specimens are unchanged by the anneal. The similarity in the PAL parameters and physical properties between the unannealed polycarbonate and the material annealed above Tg suggests that the short-term anneal does not appreciably alter the structural state of glassy polycarbonate.

UR - http://www.scopus.com/inward/record.url?scp=0001611901&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0001611901&partnerID=8YFLogxK

U2 - 10.1007/BF00580127

DO - 10.1007/BF00580127

M3 - Article

AN - SCOPUS:0001611901

VL - 25

SP - 5036

EP - 5042

JO - Journal of Materials Science

JF - Journal of Materials Science

SN - 0022-2461

IS - 12

ER -