High density polyethylene market development

In the mid-1950s a number of new thermoplastics with some very valuable properties beeame available. High-density polyethylenes produced by the Phillips process and the Ziegler process were marketed and these were shortly followed by the discovery and rapid exploitation of polypropylene. These polyolefins soon became large tonnage thermoplastics. Somewhat more specialised materials were the acetal resins, first introduced by Du Pont, and the polycarbonates, developed simultaneously but independently in the United States and Germany. Further developments in high-impact polystyrenes led to the development of ABS polymers. 

Researchers at the Chehalis facility carried out 18-months of parametric study to assess the Conrad recycling process [9]. Their objective was to identify process bottlenecks, develop operating parameters and begin to assess product value and markets. For the initial experiments a base feed mixture of 60 20 20 high-density polyethylene, polypropylene and polystyrene (HDPE PP PS) was used as representative of the major constituents found in post-consumer plastic streams. 

A good AEM should fulfill stringent mechanical, thermal, and chemical properties as mentioned in Section 11.2. Historically, the first AEM material was developed by researchers from the Toknyama Soda Company. They introduced quaternary ammonium groups to the divinylbenzene-cross-linked polychloropropene polymer matrix via trimethylamine. Since then, several membrane-associated companies explored various kinds of AEMs and pushed them to commercial market most of them were based on cross-linked polystyrene, polyvinyl alcohol, low (or high)-density polyethylene, and other aliphatic polymers through irradiation-grafting method. The primary objective of developing these materials was for applications in the fields such as electrodialysis, desalination, selective electrode, and waste acid recovery. However, they showed performance in AEM fuel cells far below practical... 

Standard Oil sold a number of licenses to manufacture high density polyethylene using their process, the first commercial product being made in Japan in 1960. The Standard Oil invention was not marketed as aggressively as the other two methods of producing high density polyethylene and played a minor role in the development of the global polyethylene industry. 

With the combined capabilities of high and low pressure production facilities it became possible to produce polyethylene resins with densities in a range of 0.91-0.96 g/cm This increased the range of products over those available prior to 1955 and permitted polyethylene to penetrate new markets and increase its utilization in existing ones. Research and development continued on both the high and low pressure polymerization processes with the goal of tailoring resins to meet the requirements of more specialized markets. 

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