Reactions of low molecular weight highly functionalized maleic anhydride grafted polyethylene with polyetherdiamines

Abstract

Reaction between low molecular weight highly functionalized maleic anhydride grafted polyethylene and several diamines were carried out using xylene as a reaction media. The influence of varying the amine to maleic anhydride (NH 2 /MAH) molar ratio and chain length of diamine on reaction was investigated. It was shown that the reactions of these materials cannot be followed by FTIR measurements alone. In these examples, colorimetric titrations were used to assess residual acid/ anhydride content that was not detected by FTIR. The reaction between anhydride and amine was observed to be fast. The degree of reaction and crosslinking in the reactor was observed to depend on the concentration of the reaction mixture and the NH 2 /MAH molar ratio. In some cases, a gelatinous insoluble mass was produced in the reactor and this material was not easily processed for further characterization. All soluble reaction products obtained were observed to be thermoplastic and could be melt processed at elevated temperatures. However, further reaction and crosslinking of these materials occurred during processing to produce thermosets, as demonstrated by rheological measurements and sintering experiments.

Study of Reaction Between a Low Molecular Weight, Highly Functionalized Polyethylene and Hexamethylenediamine

“…The initiation of the second mixing torque peak, related to crosslinking, is composition dependent and varies from 2.5 to 10 min. When compared to earlier reports utilizing high molecular weight anhydride functional polymers and low molecular weight polyamines1, 11 these results suggest that the ability to form reactive prepolymers in recent studies13–15 is not dependent upon the use of oligomeric polyether diamines. It appears to be related to the low molecular weight nature of the grafted polyethylene and the processing conditions that can be used as a consequence of these properties.…”

“…However, all the cited literature utilized high molecular weight anhydride functionalized polymers and relatively short mono or polyamines. No attempt to date has been made to investigate the same reaction between amines and anhydride functionalities grafted to low molecular weight polymers until recently 13–15. Low molecular weight polyolefins are widely marketed as waxes and used in diverse applications as polymer processing aids, aqueous dispersions, hot melt adhesive formulations,16 and compatibilizers in polymer–wood composites 17.…”

“…The low molecular weight and, associated low viscosities, enables functionalized versions of these materials to be obtained using free radical chemistry in batch processes 16, 19. This has enabled the production of fucntionalized products with grafting as high as 5.2 wt.% 13–15. Fast kinetics of the amine–anhydride reaction and the availability of highly functionalized low viscosity polyolefins and the oligomeric polyamines already in the market, provide motivation for the synthesis of novel olefin‐based thermoset materials.…”

“…Recently, the authors investigated reactions between a low molecular weight highly functionalized maleic anhydride grafted polyethylene and polyether amines both in the presence of a solvent13 and by melt mixing 14, 15. The reactor products showed little crosslinking, but significant reaction as assessed by titrations and FTIR measurements.…”

“…The objective of the current research is to study the reactions between the low molecular weight highly functionalized maleic anhydride grafted polyethylene used in the recent studies13–15 with a different co‐reactant. Hexamethylenediamine (HMDA) is a small and more compatible molecule compared to the polyether diamines used in earlier investigations 13–15. Hence, using HMDA as a co‐reactant will allow more direct comparisons to the earlier literature 1–8, 12…”