Introduction to Polymer Blends
In this introductory Chapter the basic information on polymer blends (with a special emphasis on the commercial alloys) is presented in the sequence: (i) a historical perspective on the polymer science and technology, (ii) polymeric structures and nomencl
- PDF / 739,040 Bytes
- 122 Pages / 595 x 842 pts (A4) Page_size
- 4 Downloads / 290 Views
INTRODUCTION TO POLYMER BLENDS
L. A. Utracki
National Research Council Canada, Industrial Materials Institute, Boucherville, QC, Canada
An Introductory Note In this introductory chapter the basic information on polymer blends (with a special emphasis on the commercial alloys) is presented in the sequence: (i) a historical perspective on the polymer science and technology, (ii) polymeric structures and nomenclature, (iii) fundamental concepts in polymer blend science, and (iv) evolution of polymer blends’ technology. The world production of plastics in 1900 was about 30,000 tons — in the year 2000 it is expected to reach 151 Mt. The projected saturation level on the global scale (an increase by a factor of ten) is expected to be reached in the middle of the 21st century. The rapidity of the plastics expansion can be best judged by comparing it with steel — already in 1992 the annual world production of plastics more than doubled in volume the world production of steel, and nearly tripled its value. Polymers are the fastest growing structural materials. It is noteworthy that the polymer blend segment of the plastics industry increases at a rate about three times higher than the whole. Polymers are classified as either natural that resulted from natural biosynthesis, or synthetic. The natural (polysaccharides, proteins, nucleic acids, natural rubbers, cellulose, lignin, etc.) have been used for tens of thousands of years. In Egypt the musical string instruments, papyrus for writing, and styrene [in a tree balsam] for embalming were used 3,000 BC. For millennia shellac has been used in Indian turnery [Chattopadhyaya, 1986]. The natural rubber was used by Olmecs at least 3000 years ago [Stuart, 1993]. The term synthetic polymer refers equally well to linear, saturated macromolecules (i.e., thermoplastics), to unsaturated polymers (i.e., rubbers), or to any substance based on crosslinkable monomers, macromers, or pre-polymers (i.e., thermosets). The focus of this handbook is on blends of thermoplastics made of predominantly saturated, linear macromolecules. There are many sources of information about polymer history [Martuscelli et al., 1987; Seymour and Cheng, 1987; Vogl and Immergut, 1987; Alper and Nelson, 1989; Morris, 1989; Seymour, 1989; Sperling, 1992; Mark, 1993; Sparke, 1993; Utracki, 1994, 1998a]. The abbreviations used in this text are listed in Appendix 1. International Abbreviations for polymers and polymer processing.
L.A. Utracki (Ed.), Polymer Blends Handbook, 1-122. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.
2
L. A. Utracki
1.1
Early Polymer Industry
1.1.1
The Beginnings
The polymer industry traces its beginning to the early modifications of shellac, natural rubber (NR — an amorphous cis-1,4-polyisoprene), gutta-percha (GP — a semi-crystalline trans-1,4-polyisoprene), and cellulose. In 1846, Parkes patented the first polymer blend: NR with GP partially co-dissolved in CS2. Blending these two isomers resulted in partially crosslinked (co-vulcanized) materials whose rigidity wa
Data Loading...
