Enhanced toughening of poly(propylene) with reclaimed‐tire rubber

Abstract

ABSTRACT:The dynamic vulcanization of reclaimed-tire rubber (RTR) and homopolypropylene (PP) was performed by melt-mixing using either a sulfur crosslinking agent, maleic anhydride (MA), dicumyl peroxide (DCP), or the combination of MA and DCP, in two consecutive machines, first a two-roll mill and then a counterrotating twin-screw extruder. In the case of applying a sulfur crosslinking agent, it was demonstrated that the RTR/PP blend at the ratio of 30/70 had the highest impact strength. This could be attributed to the limitation of carbon black in the blend. When the combination of MA and DCP was applied, the result was higher impact strength of the blend at the same ratio. This could be attributed to not only the cohesion between the polymer chains in each phase, PP phase and rubber phase, but also the interfacial adhesion between PP and RTR chains in these two phases. For comparison, the GRT/PP blends with and without sulfur crosslinking agent were prepared as well. All these blends showed low impact strength, which was nearly the same as that of PP. The effects of different crosslinking agents on dispersion and distribution of rubber domain size, viscosity, and percentage crystallinity were also studied.

Improving the properties of reclaimed waste tire rubber by blending with poly(ethylene‐co‐vinyl acetate) and electron beam irradiation

“…They also went on to claim the resulting properties of the blend should not attribute to changes in the EVA matrix but to changes in the particles and in the matrix/GTR interphase. Tantayanon and Juikham (2004) worked on PP/RTR blend and also observed no significant effect in the enthalpy of melting and crystallinity with increasing RTR content of the blends.…”

“…Tantayanon and Juikham (2004) showed the enthalpy of melting and blend crystallinity decreases upon sulphur crosslinking of PP/RTR blends which was due to sulphur crosslinks acting as local defects, not allowing for the close packing of PP chains. In another study, blends of PP/GTR compatibilized by dynamic vulcanization in the presence of TOR showed slight difference in melting temperature, could be due to presence of co-vulcanized TOR at the interphase slightly decreasing the lamella thickness (Awang et al, 2007).…”

“…Sonnier et al (2008) achieved in situ compatibilization between GTR particles and HDPE matrix by using a peroxide as a catalyst of dynamic co-crosslinking at the interphase. Various example of compatibilization of GTR/RTR with polymer matrices by co-crosslinking can be found in the literature (Tantayanon and Juikham, 2004, Awang et al, 2007, Punnarak et al, 2006. The co-crosslinked system can be described as interpenetrating network (IPN).…”

“…Sonnier et al (2007) used three different GTR particle sizes which were all >500 µm and did not observe significant influence of particle size on the mechanical properties of 50 wt% GTR loaded LDPE blend. Tantayanon and Juikham (2004) studied the impact strength of PP/GTR blend comprising 420 µm, 1.2mm and 2.4 mm sized particles and found only the smallest particle size gave an appreciable improvement in impact strength (20%) whereas the other two bigger particle size blends showed only marginal improvement. These observations might send a message that particle size below 500 µm is the most suitable to be used in thermoplastic blends.…”

Pengaruh Anti Oksidan Terhadap Kestabilan Sifat Fisis Bahan Polipaduan Polipropilena-Karet Alam: II. Studi Kristalinitas dan Struktur Molekul

“…Hasil menunjukkan bahwa polimer pengisi berperan dalam menurunkan tegangan luluh, kekuatan tarik dan regangan patah tetapi meningkatkan modulus elastik immiscible blends [3,6]. Sementara itu pada polipaduan jenis kompak (miscible blends) polimer pengisi lebih mampu meningkatkan kekuatan tarik dan regangan patah dibanding dengan polipaduan jenis tak kompak (immiscible blends), hal ini dikarenakan pada saat mendapatkan beban tarikan terjadi sobekan awal (craze) pada antar muka polimer matrik-pengisi pada polipaduan jenis tak kompak [7]. …”