Direct bonding between poly(oxy‐2,6‐dimethyl‐1,4‐phenylene) and rubber with radicals

Abstract

ABSTRACT:The solubility parameter value (SP value, ␦) is one of the most important factors in bonding technology. It was found that various kinds of rubber, such as VMQ (␦ Լ 7.3 cal 1/2 /cm 3/2 ) compounds, EPDM (␦ Լ 7.9 cal 1/2 /cm 3/2 ) compounds, and X-NBR (␦ Լ 9.3 cal 1/2 /cm 3/2 ), can bond to poly(oxy-2,6-dimethyl-1,4-phenylene) in their vulcanization process. This means that this bonding mechanism depends less on SP values. In this study, the bonding mechanism is hypothesized as an interfacial radical reaction, and the hypothesis is validated by molecular orbital (MO)

Direct Bonding Technology by Chemical Reactions at the Interface & the Applications of Polyamide Elastomers (PEBA)

“…The same paper [9] makes a comparative electron spin resonance (ESR) analysis of the carbon radicals generated by m-PPE and PA66 heated at 180°C and concludes that the yield of carbon radicals detected from m-PPE is roughly three times the yield from PA66, thus accounting for the difference in bonding to EPDM by m-PPE and PA66. The results are entirely consistent with our earlier experimental findings and the results from the above molecular orbital calculations [6,8].…”

“…However, our experiments have shown firstly that acid modification is not essential; secondly that, even in the same rubber recipe, differences in bonding arise according to the species and amount of crosslinker; thirdly, that even different rubbers will bond provided a suitable crosslinker is used; and finally, that a resin component compounded with an excess of heat-resistant stabiliser leads to problems with bonding. Validation of the findings by molecular orbital calculations confirmed that estimates of hydrogen-abstraction reactivity towards the resin of free radicals deriving from organic peroxide were closely consistent with the results of the actual bonding experiments [6,8]. According to the report of Yanagiya et al (Inc.) [9] published in 2006, FT-IR-ATR and other techniques have confirmed that the peroxide in EPDM migrates to the surface of the PPE resin in response to contact between EPDM compounds and a PPE resin composition (m-PPE), and that a chloroforminsoluble crosslinking layer comprising m-PPE and EPDM is formed.…”

“…Table 4 in comparison with conventional PAE. 1.2 Direct vulcanisation bonding to rubber [2,3,5,6,8] As stated at the outset, the basis on which the new PAE was developed was direct bonding technology for thermoplastic and rubber. Thus, the new PAE grades also allow direct vulcanisation bonding to rubber.…”

“…Table 2 gives an overview of the bonding mechanisms involved. Although subsumed under the same term K&K, the bonding mechanisms are not all the same and in practice three broad categories can be distinguished: molecular diffusion (bonding between polyphenylene ether (PPE) based materials and styrene based rubber/ elastomer [2,3,5]), chemical bond formation by free radicals [2,3,6] (chiefly bonding between peroxide cured rubber and PPE or polyamide materials), and bonding by ionic reaction (bonding between polyamides and fluoropolymers, acid-modified rubber or thermoplastic polyurethanes (TPU)) [4].…”

Effect of co‐agents on adhesion between peroxide cured ethylene–propylene–diene monomer and thermoplastics in two‐component injection molding

“…These TPVs exhibited improved mechanical properties and lower compression sets. More specifically for multicomponent injection molding, direct bonding was achieved between polyphenyl ether (PPE) and EPDM with radicals . This EPDM consisted of a peroxide curing agent and TMPT as co‐agent.…”