One of the ironies of the tragic fire at Evonik’s CDT (cyclododecatriene), plant in Marl, Germany almost a month ago is that it is creating a significant market opportunity for a renewably sourced polyamide.
Chemist Wallace Carothers invented polyamides at DuPont in 1927, and since then the material has become ubiquitous as an engineering plastic, in part due to its many chemical modifications. Most common is 6/6, but there are many other iterations for specialized applications.
Chemische Werke Huels AG of then West Germany opened the first precursor synthesis production plant in 1966 to produce polyamide 12, a version with reduced nitrogen that has excellent toughness and chemical resistance. Polyamide 12 was introduced at K’63 with material from a pilot plant. There is some sacrifice in thermal properties with polyamide 12, but it found niche applications in a variety of markets where its chemical resistance in particular was valued. A flexible version became sole sourced in flexible fluid hoses used in cars and trucks.
The Evonik fire at a plant that produced about 70% of the global feedstock for polyamide 12 has created a short-term crisis for automotive engineers, who are now scrambling to find substitutes. The fact that automotive sourcing professionals allowed this material to be sole sourced without ready backups was the subject of an earlier discussion.
Evonik and Arkema, the two primary producers of polyamide 12, also make bio-polyamides they are proposing as substitutes. For example, Arkema has expanded its Rilsan (bio-polyamide) HT (high temperature) range with an ultra-flexible grade that is close to the flexibility of polyamide extrusion grades. It’s the first flexible polyphthalamide (PPA)-based material to replace metal in high-temperature tubing applications. Rilsan HT is up to 70% based on a renewable non-food-crop vegetable feedstock (castor oil). Compared with conventional, petroleum-based high-temperature plastics, CO2 emissions are substantially lower and fossil resources are conserved. Evonik also has a version.
Until five years ago, Arkema was the only producer of bio-polyamide, which was developed by IG Farben during World War II in the face of shortages of oil in Germany. Now there are six other major producers: Evonik, BASF, DuPont, Rhodia, DSM, and Verdyzene.
A report I wrote for BCC Research projects a 29% annual growth rate for bio-polyamides through 2016. That may be a conservative estimate based on the new developments. Interestingly, the bio-polyamides are significantly less expensive than polyamide 12, whose price has exploded above $5 per pound. Prices of many of the bio-polyamides are in the $2.30 to $4.50 per pound range.
Nylon is the commonly used name of linear polyamides that have the carbonamide group –CO—NH– recurring in a chain of methylene groups.
The Spotlight on Polyamide 12
The fire at the Evonik CDT plant has put a spotlight on an obscure chemical niche—polyamide 12.
There are five producers: Evonik with a capacity of approximately 50,000 metric tons per annum; Arkema, 23,000; EMS-Grivory, 18,000; Shandong Guangyin New Materials, 10,000 (new in 2012); and Ube, 9,500. The total amount produced last year was approximately 98,000 metric tons. Before the fire, demand oupaced supply by as much as 20%.