We’re living at a time of unprecedented development through the power of the human mind, creativity and innovation offering an enriched quality of life, while accompanied simultaneously by uniquely man made potential disasters, in terms of the environment. From a Jewish point of view, the fact that humankind is able to make a difference to the world we live in, even manipulate its fundamental elements for our benefit, is routed in the notion that man is a partner in creation,[1] and man is made to toil and work.[2] At the same time, man is charged with responsibility to fix the world that is imperfect: everything that was created needs fixing.[3] One of the disasters of our times includes the development of materials that previously did not exist. In previous ages, materials used in construction and daily use were natural materials that were simply part of the fabric of the natural world and were rapidly biodegradable. With the innovation of synthetic materials however the world has become confronted by a uniquely man made disaster: the daily use of single-use items that are practically not biodegradable with no solution over hundred years after its invention. This is pertaining to a simple seemingly benign innovation: the use of plastic bottles and packaging, 95% of which is only being used once and then discarded.
Plastic is a polymer that consists of repetitive molecules ad infinitum made from the chemical compounds of phenol and formaldehyde (PF). Its use in everyday life was made possible by Leo Hendrik Baekeland, a Belgian-born American living in New York State in 1907, who invented the first viable, cheap plastic, based on a synthetic polymer. The problem with this invention is that while convenient, compared to other materials, like leather, thread, cotton, rope, nylon and even tin, which decompose within fifty years, plastic bottles can take up to 450 years to decompose. Biodegradable materials, which consist of organic matter, such as food scraps, plant trimmings, paper, wood and grass clippings will decompose under certain weather, water, and oxygen conditions over a relatively short period of time, such as months to a few years. For every problem there must be a solution and as the problem is man-made so must be the attempt for a solution.
The recent ‘UK Plastics Pact’ has an ambition to tackle this problem by making 100% of plastic packaging ready for recycling or composting by 2025. The set of pledges in the act to tackle plastic pollution over the next seven years include: 1. Eliminate difficult or unnecessary single use plastic packaging through better design. 2. Make 100% of plastic packaging reusable or recyclable or compostable. 3. Make sure 70% of plastic packaging is recycled or composted. 4. 30% of all plastic packaging to include recycled material. More than 40 companies, responsible for more than 80% of plastic packaging on products sold through UK supermarkets, have signed up to the act. In brief, two approaches are articulated to confront the problem of plastic pollution of the environment: 1. To ensure more plastic is recyclable 2. To make sure plastic is compostable.
There are two processes that are broadly referred to as ‘compostable’. The first is that an object can be broken down in a process that results in compost or humus - the organic component of soil, formed by the decomposition of leaves and other plant material by soil microorganisms. A second is ‘biodegradable’, which broadly means that an object can be biologically broken down through chemical acidic additives, like polyethylene. As a polymer consists of a chain process (polymerization) of molecules that repeats itself ad infinitum, the aim of the additive is to break this process and speed up its decomposition.
Work on making plastic biodegradable began in the 1970s when polyethylene terephthalate, known as PET, began to be used in packaging for liquids and foodstuffs. The reason for its use is due to PET’s excellent water-repellent properties that led to it being the plastic of choice for soft drink bottles. However, once plastic bottles are discarded in the environment the water resistance of PET means that they are highly resistant to natural biodegradation. PET bottles can linger for hundreds of years and plastic waste like this will accumulate over time unless a solution is found to degrade them.
This was an area that scientists worked on in the early 1970s at Imperial Chemical Industries (ICI), the largest chemical industries manufacturer in Britain, including my father Dr. D.S. Brackman, who wrote his thesis on the ‘Polymerisation of Stilbene’ at Manchester University in 1952 before eventually moving to ICI where he undertook research on degradable plastics composition, among other areas of polymer interest at that time.
In 1974 his research was patented[4] assigned to ICI, and subsequently cited in relevant literature on the subject as recently as 2016. In the opening, he outlines the purpose of the paper:
This invention relates to thermoplastics compositions. The use of disposable plastics wrappings, containers and the like and their subsequent discarding, either intentionally or accidentally, has led to the problem of plastics litter. This invention relates to a plastics composition the use of which can alleviate the problem.
The research proceeds to claim that to alleviate the problem, the plastic composition in its polymer stage could include iron stearate plus extra stearic acid to serve as a synergistic prodegradant, together with metal carboxylate and free carboxylic acid.
He writes:
Thermoplastics compositions, especially polyolefine composition, contain a metal carboxylate plus a free carboxylic acid as a synergistic prodegradant. Iron stearate plus extra stearic acid is an effective mixture for low and high density polyethylene.
The experiment consisted of exposing the samples to ultra violet irradiation using a combination of equal numbers of 20 watt fluorescent sunlamps and 20 watt black lamps. The samples circulated around the lamps at a distance of 10 cm from the lamps. The samples were inspected daily and tested for flex-crack failure. The time to failure indicates the effect of the prodegradant, a shorter time indicating a more effective prodegradant. The results showed that both the acid and the salt have prodegradant activity but the two together give an enhanced and more rapid effect.
In a further study in 1973 entitled ‘Some fundamental aspects of polymer photodegradation’, D.S. Brackman further demonstrated how one could increase the rate of photodegradation (the alteration and embrittlement of materials through the combined action of sunlight and air) of polymers and accurately assess the onset of embrittlement in a wide range of prodegradant formulations. Together with A.W. Birley, he determined the environmental factors, such as the amount and temperature of heat, which affects the rate of photodegradation. Nevertheless, he concludes the rate of thermal oxidation of photo oxidized embrittled polyolefines, even when 60 ppm of iron salt is present, is very low at soil temperatures.
This research indicates the effort put into trying to discover the most effective prodegradant, as well as to find a faster rate of photodegradation, as far back as the early 1970s. Interestingly, nearly 50 years later this problem remains, thus the urgency of the UK Plastics Act. This balance of innovation and responsibility continued in my father’s work[5] in 1979 on a heat exchanger of thermoplastic materials, e.g. polypropylene, to be readily adapted for use as a solar energy collector. An interesting use of plastics by D.S. Brackman was the use of corrugated plastic and polythene sheets in the building of his Sukkah (booth) for the Jewish holiday of Sukkot, thereby ensuring a positive and spiritual use for this synthetic material that was only possible through man’s innovation and resourcefulness.
In conclusion, the combination of social responsibility and care for the environment coupled with progress and innovation, as well as endowment of spiritual meaning where possible, is what makes us, from a Jewish perspective, partners in creation, ensuring the world remains sustainable and a healthy place to dwell in for generations to come.
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[1] Talmud Shabbat 10a; 119b.
[2] Job 5:7; Talmud Sanhedrin 99b.
[3] Genesis Rabba 11:6. According to Rashi on Genesis Rabba 11:6, the statement that the world was very good is not a contradiction with the fact that the world also needs fixing.
[4] Patent no. US3840512A & CA1090498A.
[5] Bibliographic data: US4150720 (A) - 1979-04-24: The heat exchanger comprises of two spaced-apart headers interconnected by an extruded board comprising a plurality of tubular passages extending from one end of the board to the other; each header having a longitudinal groove in its exterior surface and a plurality of holes spaced along the groove, interconnecting the groove and the interior of the header; each end of the board being located along the groove of one of the headers and held in position by a sealing bead adhering to both the header and the board, the bead extending continuously right round the mouth of the groove where adjacent to the board, to seal against loss of any fluid flowing between the header and the tubular passages. The heat exchanger can be readily adapted for use as a solar energy collector. The board and headers are preferably polypropylene extrusions secured together and sealed by extrusion welding using an extruded bead of a polypropylene composition.