Waldo Lonsbury Semon was born into a family which had seen its share of American history. His father was an engineer, involved in construction projects throughout the country whilst two of his uncles had been involved in building the Great Northern Railroad. His grandfather fought in the Civil War and against the Soux with General Custer whilst his father, Semon’s great-grandfather, had crossed the country from east to west at the time of the Californian gold rush. In contrast, the maternal side of his family had a literary bent and Waldo’s genes seemed to represent a perfect fusion of these two sides of his family.

His father travelled extensively, working on numerous engineering projects (Waldo claimed he had “itchy feet”) which resulted in his living in a different place for almost each year of his school life. However, he was fascinated by books and learned to read and write before he entered school in 1904. His early reading seemed to be shared between his father’s engineering textbooks and Shakespeare!

His fascination with applied science soon led to experimentation. He built a battery and electric buzzer at the age of nine and then tried to re-charge dead batteries from the live rail of the local electric railway. He and two friends cast their own cannons which they charged with black powder to fire wooden missiles and, to show that chemistry also was an interest at that early age, he attempted to dye his aunt’s (white) cat black with silver nitrate. The resulting red, black and white tricoloured cat was, perhaps, his first intimation that practical and theoretical chemistry often follow divergent paths.

His first part-time job, aged 11, did not suggest a career in science as it was with Bill Cody’s Wild West Show where his pay was being taught to shoot by Buffalo Bill himself. His next summer job was with an electrical company and electricity and radio transmission became his new passion. Moving to Ashland he set up his first laboratory above the stables of the new family home but his father was soon on the move again to Oregon where, here at least, he achieved two consecutive years of education before moving on yet again.

In spite of all these moves, his avid reading and experimentation gave him an academic knowledge well in advance of most of his classmates but, now 18 years old, he still had no career ideas in mind. Enlightenment came when the National Bureau of Standards refused him a research position because he had no degree and Mr Miller (a co-founder of Boeing) offered him an immediate position but pointed out that, ultimately, paper qualifications mattered and he should get himself some!

He therefore enrolled at the University of Washington where a degree in engineering should have been his obvious choice but, perhaps because of his father’s wandering lifestyle and a reluctance to continue this for the rest of his life, he chose chemistry as his main subject. Unfortunately his family was soon on the move again so he had to organize accommodation and pay for it. This he did by working evenings and Sundays as a janitor in the university. It was during his first term at University that he met Marjorie Gunn who was also studying chemistry and would, eventually, become his wife.

Perhaps because of his upbringing, Waldo had always been interested in the appliance of knowledge to practical considerations and this led him to switch from pure chemistry to chemical engineering where he was soon recognised as being a brilliant experimentalist.

By now it was 1918 and the US army took him from his studies but quickly realised his abilities and set him to work at the university on army projects. Developing a new manufacturing process for TNT must have taken him straight back to his childhood! He finally graduated in 1920 and he and Marjorie were married in September of that year. Waldo then set out on his post-graduate degree, funded by some teaching, whilst his wife tutored students at the university.

At the end of this first year, when the colleges closed, their combined incomes fell to zero but Semon obtained a job in a factory which generated gas from oil and coke but which wanted to switch to using local coal. By the end of the summer he had succeeded but the cost of the plant conversion proved too high for the process to be viable. On the “plus” side, the university heard of his success and offered him a position as Assistant Chemistry Instructor. He was now reasonably settled with a number of research projects and a plot of land near Seattle where he was building a house. More stability was provided by the birth of two daughters, Mary and Marjorie, in 1922 and 1924. A third, Constance Anne, was to follow in 1929. But life is rarely that simple and in 1925, funding changes at the university put an end to his external contracts forcing him to look for a more lucrative position.

About this time B F Goodrich of Akron Ohio, a company known worldwide for its rubber products and, in particular, automotive tyres, was starting to think of developing a synthetic rubber to replace the natural material sourced from the far side of the world. The man in charge of chemical research at Goodrich was Dr Trumbull who had been Semon’s Professor of Chemistry in his first year at university and, remembering the abilities of his young student, he offered him the job of inventing this material. Semon accepted and decided to drive to Akron with his family rather than go by train. His interest in developing an improved automotive tyre grew rapidly as he experienced 14 punctures over the two-week journey!

His first project was to synthesise a material which could replace natural rubber as a tank lining material and which could be stuck to the metal tank (or tubes) with Goodrich’s existing ‘Vulcalock’ rubber-to-metal adhesive. He immersed himself in Goodrich’s library, studied what was known about synthetic polymers and decided to investigate the field of vinyl polymers. These were not new materials but, as understood, were commercially valueless. The year was 1926 and within a few months he had made polyvinyl chloride (PVC) – a hard white powder first synthesised towards the end of the 19th century. What Waldo discovered, and others had missed, was that when the powder was dissolved in certain solvents it swelled to form a gel which was mouldable and had certain rubber-like properties, its hardness and ‘rubberyness’ depending on the amount of solvent present.

Unfortunately he could not bond it to metal – which had been the purpose of the research – but Goodrich got some early return for its investment by way of PVC shoe heels and coated chemical racks. This was not sufficient to provide the company with the return it needed to keep on developing the material and it was on the point of backing out when Semon came up with the idea of coating fabrics to give waterproof materials and of producing soft flexible PVC sheets for applications such as shower curtains. The company vice-president whom he had to convince was a keen camper who was used to being soaked inside his ‘waterproof’ tent so Semon got his ‘green light’ and in 1931 a range of products hit the unsuspecting market. The name “Koroseal” was proposed for PVC by Goodrich’s Director of Research and soon became the registered trademark. Waldo Semon was granted the US Patent for PVC in 1933, No. 1929453.

This was actually Semon’s 22nd US Patent, the others including amine antioxidants, the adhesive “Plasticon” based on scrap rubber, bookbinding using adhesives instead of stitching and chewing gum!

With the success of PVC behind him, Semon returned to his search for a synthetic elastomer to replace natural rubber in automotive tyres. The rise of Hitler and the possibility of the US being isolated from its sources of the natural material concentrated Semon’s, Goodrich’s and the US government’s minds individually and collectively. He soon decided that the polymerisation of butadiene offered the most likely route to a viable synthetic elastomer but the practical difficulties in obtaining a high polymer were formidable and it was only in 1939 that he got the breakthrough he needed to synthesise a useful material. This, blended with natural rubber, was quickly used to manufacture some automotive tyres and surpassed all expectations with practically determined life expectancies of over 50,000 miles. Goodrich christened the elastomer, which we now know as polybutadiene or BR, “Ameripol” whilst the tyres, launched in June 1940, were named “Liberty Tyres”. Whether this referred to a freedom from Eastern sources of natural rubber or was prescient of their importance over the next five years is not reported!

The following year, Goodrich agreed to make available its confidential process to its competitors so that the US could increase output in anticipation of its contribution to the anti-Nazi war effort. Semon was appointed Chairman of the Technical Committee which had been set up to coordinate the synthesis of Ameripol and the manufacture of tyres from it. Directly out of this extended research came “GR-S” or SBR (styrene-butadiene rubber) and these two synthetic elastomers remain today the general-purpose rubbers of choice to replace or blend with the natural material.

In 1943 Semon was made Director of Pioneering Research at Goodrich but he could not get away from PVC which was now being use to manufacture many dozens, if not hundreds, of products ranging from hose pipes to electric plugs and plastic toys of every description. The age of tinplate was at an end. PVC resin was marketed under the trade name “Geon” although it was known world-wide just as “vinyl”. In 1993 that part of Goodrich concerned with PVC was spun off as the independent Geon Corporation and in 2000 Geon merged with M A Hannah Co. to form the PolyOne Corp.

Waldo Semon continued to work for Goodrich until his 65th birthday in 1963 when he ‘retired’ and took a teaching post at Kent State University but by 1971 his eyesight was failing rapidly and he had to quit. Even then he was in considerable demand as a consultant and expert witness whilst, in his spare time, he worked his vegetable garden. In his eighties he was still teaching, informally, at local schools where he believed in the “catch them young” philosophy of inspiring children with enthusiasm for investigative science. In 1979 Marjorie died. Waldo survived her for some 20 years, passing away on May 26th 1999.