Homogeneous and Heterogeneous Solid State Self-Healing System

Abstract

The solid state self-healing system was obtained by employing a thermosetting epoxy resin, into which a thermoplastic is dissolved. The aim of this study is to investigate the homogeneous and heterogeneous solid state self-healing system by using thermoplastics comprised of poly(bisphenol-A-co-epichlorohydrin) (PDGEBA), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), polyethylene (PE) and polypropylene (PP) as healing agents. PDGEBA produced homogenous resin blend which undergone random molecule diffusion healing process. A heterogeneous resin blend composed of 8 wt.% PVC, PVA PE, and PP, yielding a “bricks and mortar” morphology wherein the epoxy phase exists as a matrix (mortar) interpenetrated with a percolating thermoplastic (bricks). The healing process in heterogeneous resin blend is attributed to volumetric thermal expansion of healing agent above its melting point in excess of epoxy brick expansion. Healing was achieved by heating the fractured resins to a specific temperature; above their glass transition temperature (Tg) which obtained from dynamic mechanical analysis (DMA) in order for diffusion process and thermal expansion to occur. The thermal properties and bonding formed in the epoxy resins were characterized by means of Fourier Transform Infrared Spectroscopy (FTIR) and dynamic mechanical thermal analysis (DMTA). Izod impact test and compact tension test were conducted to demonstrate details self-healing capability of different specimens. Results of Izod impact test are in agreement with the result of compact tension test. Under compact tension test, the healable resin with PDGEBA has the highest healing efficiency of 60% followed by PVC, PP, PE, and PVA with 39%, 37%, 28% and 21% of average percentage healing efficiencies in three healing cycle respectively. Morphological studies using optical microscope verified the fracture-healing process and morphological properties of the resins.

Keywords

Solid state self-healing Homogeneous blend Heterogeneous blend Healing efficiency Compact tension test

References

Pang

J.W.C.

and Bond

I.P.

(2005b). ‘Bleeding composites’—damage detection and self-repair using a biomimetic approach. Composites Part A: Applied Science and Manufacturing, 36 (2): 183–188.

D.Y.

Meure

and Solomon

(2008). Self-healing polymeric materials: A review of recent developments. Progress in Polymer Science, 33 (5): 479–522.

Astrom

B.T.

, Manufacturing of polymer composites. 1997: CRC Press.

Charalambides

Hardouin

Kinloch

and Matthews

(1998). Adhesively-bonded repairs to fibre-composite materials I. Experimental. Composites Part A: Applied Science and Manufacturing, 29 (11): 1371–1381.

Jud

Kausch

H.H.

and Williams

J.G.

(1981). Fracture mechanics studies of crack healing and welding of polymers. Journal of Materials Science, 16 (1): 204–210.

Trask

R.S.

Williams

H.R.

and Bond

I.P.

(2007). Self-healing polymer composites: mimicking nature to enhance performance. Bioinspiration and Biomimetics, 2 (1): 1–12.

Kalista

S.J.

and Ward

T.C.

(2007). Thermal characteristics of the self-healing response in poly(ethylene-co-methacrylic acid) copolymers. Journal of The Royal Society Interface, 4 (13): 405–411.

Murphy

E.B.

and Wudl

(2010). The world of smart healable materials. Progress in Polymer Science, 35 (1–2): 223–251.

Blaiszik

B.J.

Kramer

S.L.B.

Olugebefola

S.C.

Moore

J.S.

Sottos

N.R.

and White

S.R.

(2010). Self-Healing Polymers and Composites. Annual Review of Materials Research, 40: 179–211.

10.

Hou

and Hayes

(2002). A resistance-based damage location sensor for carbon-fibre composites. Smart Materials and Structures, 11 (6): 966.

11.

Hayes

S.A.

and Jones

F.R.

, Self healing composite materials, in UK Patent Application 2004.

12.

Hayes

S.A.

Zhang

Branthwaite

and Jones

F.R.

(2007b). Self-healing of damage in fibre-reinforced polymer-matrix composites. Journal of The Royal Society Interface, 4 (13): 381–387.

13.

Hayes

S.A.

Jones

F.R.

Marshiya

and Zhang

(2007a). A self-healing thermosetting composite material. Composites Part A: Applied Science and Manufacturing, 38 (4): 1116–1120.

14.

Meure

Varley

R.J.

D.Y.

Mayo

Nairn

and Furman

(2012). Confirmation of the healing mechanism in a mendable EMAA–epoxy resin. European Polymer Journal, 48 (3): 524–531.

15.

Meure

D.Y.

and Furman

(2009). Polyethylene-co-methacrylic acid healing agents for mendable epoxy resins. Acta Materialia, 57 (14): 4312–4320.

16.

Hoy

(1970). New values of the solubility parameters from vapor pressure data. Journal of Paint Technology, 42 (541): 76–118.

17.

Chen

Dam

M.A.

Ono

Mal

Shen

Nutt

S.R.

Sheran

and Wudl

(2002). A Thermally Re-mendable Cross-Linked Polymeric Material. Science, 295 (5560): 1698–1702.

18.

Hayes

B.S.

and Seferis

J.C.

(2001). Modification of thermosetting resins and composites through preformed polymer particles: A review. Polymer Composites, 22 (4): 451–467.

19.

Rahmathullah

M.A.M.

and Palmese

G.R.

(2009). Crack-healing behavior of epoxy–amine thermosets. Journal of Applied Polymer Science, 113 (4): 2191–2201.

20.

Kong

E. S.-W.

, Physical aging in epoxy matrices and composites, in Epoxy Resins and Composites IV. 1986, Springer. p. 125–171.

21.

Wool

R.P.

(2008). Self-healing materials: a review. Soft Matter, 4 (3): 400–418.

22.

Luo

Eberly

D.E.

Singhal

Viratyaporn

and Mather

P.T.

(2009). A thermoplastic/thermoset blend exhibiting thermal mending and reversible adhesion. Applied Materials and Intefaces, 1 (3): 612–620.

23.

Wool

R.P.

and O'Connor

K.M.

(1981). Craze healing in polymer glasses. Polymer Engineering and Science, 21 (14): 970–977.

24.

Jones

Zhang

and Hayes

(2008). Thermally Induced Self Healing of Thermosetting Resins and Matrices in Smart Composites. Self Healing Materials: 69–93.

25.

Zhang

, Self Healing Epoxy Resins and Composites, in Department of Engineering Materials 2008, University of Sheffield.