Injection Molding Poly(Para-phenylene) with a Rapidly Heated Mold

Kimerling, Thomas E.; Yao, Donggang; Kim, Byung H.

doi:10.1080/03602550903092518

Cited by 3 publications

(1 citation statement)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Various types of PPP with different side groups have been investigated as structural materials, and modulus values ranging from 5 GPa to 9 GPa and tensile strengths ranging from 120 MPa to 200 MPa have been reported . PPP is an amorphous thermoplastic, and can be formed by extrusion, hot compression molding, injection molding, or solution casting . Since PPP is amorphous it does not require prescribed cooling rates or subsequent heat treatments to achieve the desired properties, which are often required for increasing crystalline volume fraction in polymers like PEEK …”

Section: Introductionmentioning

confidence: 99%

Shape‐memory behavior of high‐strength amorphous thermoplastic poly(para‐phenylene)

Collins

Yakacki

Lightbody

et al. 2015

J of Applied Polymer Sci

View full text Add to dashboard Cite

The purpose of this study was to investigate the shape-memory behavior of poly(para-phenylene) (PPP) under varying programming temperatures, relaxation times, and recovery conditions. PPP is an inherently stiff and strong aromatic thermoplastic, not previously investigated for use as a shape-memory material. Initial characterization of PPP focused on the storage and relaxation moduli for PPP at various frequencies and temperatures, which were used to develop continuous master curves for PPP using timetemperature superposition (TTS). Shape-memory testing involved programming PPP samples to 50% tensile strain at temperatures ranging from 1558C to 2058C, with varying relaxation holds times before cooling and storage. Shape-recovery behavior ranged from nearly complete deformation recovery to poor recovery, depending heavily on the thermal and temporal conditions during programming. Straining for extended relaxation times and elevated temperatures significantly decreased the recoverable deformation in PPP during shape-memory recovery. However, PPP was shown to have nearly identical full recovery profiles when programmed with decreased and equivalent relaxation times, illustrating the application of TTS in programming of the shape-memory effect in PPP. The decreased shape recovery at extended relaxation times was attributed to time-dependent visco-plastic effects in the polymer becoming significant at longer time-scales associated with the melt/flow regime of the master curve. Under constrained-recovery, recoverable deformation in PPP was observed to have an exponentially decreasing relationship to the bias stress. This study demonstrated the effective use of PPP as a shape-memory polymer (SMP) both in mechanical behavior as well as in application.

show abstract