1 Introduction
“. . .macromolecular chemistry appears today to fit between low molecular organic chemistry
and cytology. It is the connecting link between them, growing systematically out of low
molecular chemistry but, with the incomparably larger wealth of its chemical scope, forming
living matter. . .. In the light of this new knowledge of macromolecular chemistry, the wonder
of life in its chemical aspect is revealed in the astounding abundance and masterly
macromolecular architecture of living matter.”
Hermann Staudinger, Nobel Lecture, 1953 [1]
Macromolecular chemistry and biology were closely linked at the start. In the
introduction to his scientific autobiography [2], Hermann Staudinger tells us,
“I did not intend to study chemistry. I preferred botany, because from an early
age I had been interested in floristics. . .” The controversy that surrounded Professor
Staudinger’s macromolecular hypothesis in the early days is well known to readers
of this volume. Natural polymers figure prominently in this story, beginning with
the demonstration that the hydrogenation of natural rubber does not destroy its
macromolecular character [3]. In his 1970 article, “The macromolecular concept
and the origins of molecular biology,” historian Robert Olby argues that key
evidence in favor of the covalent structure of macromolecules was provided in
the 1920s by independent measurements of the molecular weight of hemoglobin.
Ultracentrifugation produced a “clear band” and an estimated molecular weight of
68,000, while osmotic methods yielded a value of 66,500 [4]. The implication of
monodispersity in the ultracentrifugation result, coupled with the consistency in
molecular weights determined by two different methods, argued against aggregation through non-covalent forces as the origin of the macromolecular behavior of
hemoglobin. Olby goes on to cite Staudinger’s “biologists’ viewpoint” as central to
his early investigations of macromolecular chemistry.
As the commercial value of synthetic polymers grew through the mid-twentieth
century, studies of natural and synthetic polymers diverged. The remarkable physical
properties of synthetic polymers, along with their ease of processing and relatively
low cost, led to extraordinary growth in industrial polymer production. At the same
time, structural and biophysical studies of DNA [5] and proteins [6] began to reveal
the molecular origins of genetic information, enzyme catalysis, and immune
recognition. Polymer chemistry and physics became closely aligned with materials
science and engineering, while the study of proteins and nucleic acids formed the
core of the new discipline of molecular biology. Moreover, the two fields were
distinguished by the relative value each placed on the complementary roles
of synthesis and analysis. Few biologists shared the view of Jacques Loeb, who
“considered the main problem of biology to be the production of the new, not the
analysis of the existent” [7]; in contrast, the polymer chemistry community was
driven, both by curiosity and by the prospect of practical impact and financial return,
to explore a broad range of synthetic routes to new macromolecular materials. Just
10 years after Staudinger received his Nobel Prize, Karl Ziegler and Giulio Natta
were honored similarly for their development of new synthetic methods that enabled
the production of polyolefins with unprecedented control of structure and properties.
200
D.A. Tirrell
“. . .macromolecular chemistry appears today to fit between low molecular organic chemistry
and cytology. It is the connecting link between them, growing systematically out of low
molecular chemistry but, with the incomparably larger wealth of its chemical scope, forming
living matter. . .. In the light of this new knowledge of macromolecular chemistry, the wonder
of life in its chemical aspect is revealed in the astounding abundance and masterly
macromolecular architecture of living matter.”
Hermann Staudinger, Nobel Lecture, 1953 [1]
Macromolecular chemistry and biology were closely linked at the start. In the
introduction to his scientific autobiography [2], Hermann Staudinger tells us,
“I did not intend to study chemistry. I preferred botany, because from an early
age I had been interested in floristics. . .” The controversy that surrounded Professor
Staudinger’s macromolecular hypothesis in the early days is well known to readers
of this volume. Natural polymers figure prominently in this story, beginning with
the demonstration that the hydrogenation of natural rubber does not destroy its
macromolecular character [3]. In his 1970 article, “The macromolecular concept
and the origins of molecular biology,” historian Robert Olby argues that key
evidence in favor of the covalent structure of macromolecules was provided in
the 1920s by independent measurements of the molecular weight of hemoglobin.
Ultracentrifugation produced a “clear band” and an estimated molecular weight of
68,000, while osmotic methods yielded a value of 66,500 [4]. The implication of
monodispersity in the ultracentrifugation result, coupled with the consistency in
molecular weights determined by two different methods, argued against aggregation through non-covalent forces as the origin of the macromolecular behavior of
hemoglobin. Olby goes on to cite Staudinger’s “biologists’ viewpoint” as central to
his early investigations of macromolecular chemistry.
As the commercial value of synthetic polymers grew through the mid-twentieth
century, studies of natural and synthetic polymers diverged. The remarkable physical
properties of synthetic polymers, along with their ease of processing and relatively
low cost, led to extraordinary growth in industrial polymer production. At the same
time, structural and biophysical studies of DNA [5] and proteins [6] began to reveal
the molecular origins of genetic information, enzyme catalysis, and immune
recognition. Polymer chemistry and physics became closely aligned with materials
science and engineering, while the study of proteins and nucleic acids formed the
core of the new discipline of molecular biology. Moreover, the two fields were
distinguished by the relative value each placed on the complementary roles
of synthesis and analysis. Few biologists shared the view of Jacques Loeb, who
“considered the main problem of biology to be the production of the new, not the
analysis of the existent” [7]; in contrast, the polymer chemistry community was
driven, both by curiosity and by the prospect of practical impact and financial return,
to explore a broad range of synthetic routes to new macromolecular materials. Just
10 years after Staudinger received his Nobel Prize, Karl Ziegler and Giulio Natta
were honored similarly for their development of new synthetic methods that enabled
the production of polyolefins with unprecedented control of structure and properties.
200
D.A. Tirrell