Reflections on Aging and Thermoplastics

Decades ago I was a mechanical engineer before I went into international missions. Unlike some I don’t think I ever was very successful at leveraging the skills of engineering in my missions work and theological reflection. However, when my wife and I were asked to speak on retirement and aging (a topic rapidly becoming more relevant to us) I was reminded of something I did in my past profession.

Working on my Master’s at Old Dominion University, I did my thesis research on the topic of physical aging in glass-reinforced pultruded composites. The thermoplastics used in pultruded composites undergo a process known as “physical aging.” This is a process of crystallization of the plastic. As it does so, it becomes less flexible, less resilient, and more brittle. In some applications this process may not matter. However, in others, this process will reduce the useful life of a plastic object.

There are, then, three major ways in which a plastic item will negatively respond to time.

–Physical damage. By repeated use, accident, or mistreatment, an object may be broken or damaged. The damage can be partly reversed through repair. Additionally, the ability to prevent physical damage is limited.

–Chemical aging. This is a breakdown of the thermoplastic due to environment. The environment may have ultraviolet radiation, high temperatures, oxidizing/corrosive chemicals, and more. These break down the polymers changing the properties of the plastic object. One may have some ability to limit chemical aging through preventive care. However, once the damage is done, it is irreversible.

—Physical aging. This is the embrittlement of thermoplastics due to gradual crystalization of the polymer. Unlike the other two forms of degradation, this is reversible. One can go through a heat treatment where crystallization is reversed and the original properties of the thermoplastic are restored.

How do these compare to how we age?

Aging of Thermoplastic ObjectsEquivalent Aging in HumansOur Level of Control Over ItReversible?Physical Damage

Accidents, Acts of Malice, and
“Acts of God.”
ModerateLimited (Repair only)Chemical AgingNatural breakdown of our bodies and mind as we age.LimitNoPhysical Aging“Embrittlement” of mind and behavior— getting “stuck in a rut.”HighYes

In our lives we can use proper safety precautions to minimize physical damage. One cannot prevent everything, and some things will need to be repaired as necessary.

As we age, there is also the natural breakdown of our bodies and minds. Diet, exercise, and general healthy living can slow down the process, but it is not really reversible.

These are all important. But I wonder if not enough importance is given to the third area. This type of aging is reversible in us along with thermoplastics. We can become “embrittled”— unable to be flexible in mind and behavior. Breaking patterns of behavior periodically, having a clear sense of meaning/purpose, A study (sorry, I don’t have the citation in front of me so you are welcome to be skeptical) recently done showed that having a strong sense of purpose reduced premature death in a group by up to 23%. Purpose gives direction, but also keeps one flexible since purpose is given a higher priority than pattern. Likewise, having a strong social network also helps. Social connections do provide a certain sense of pattern, but also forces a certain amount of flexibility as well. A different study (Sorry… research it yourself) had linked a strong social support system for the elderly with up to 29% reduction of premature death. Obviously learning new skills, taking on new challenges, embracing new roles are often described as things that “keep us young.” In a sense that is true.

This third category (I will call embrittlement) is the only area of aging that is thoroughly reversible. Now I am not anti-aging. I am not anti-death. Being against them don’t keep them from happening anyway.

The challenge really is to Age Well, and to Die Well. I would argue that we have some control in all three areas. It is good for each of us to identify which problem fits into which category.

— Some things we need to take safety measures as needed, to lessen the number of serious accidents or mishaps.

— Some things we need to develop preventative habits to reduce the speed of our gradual breakdown.

— Some things need to be done to keep us from becoming stuck in a cycle the makes our world smaller and reduce the expanse of possibilities before us.

All three are important.