Acetals as nucleating agents for polypropylene
| Autor: | Kristina A. Garbriel, Raymond J. Brambilla, Yash P. Khanna, Long Kim Bui, Tammy L. Smith, Divakaran Masilamani |
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| Rok vydání: | 1994 |
| Předmět: |
chemistry.chemical_classification
Polypropylene Materials science Polymers and Plastics Diastereomer General Chemistry Polymer Xylitol Surfaces Coatings and Films law.invention Crystallinity chemistry.chemical_compound chemistry law Ultimate tensile strength Materials Chemistry Organic chemistry Sorbitol Crystallization |
| Zdroj: | Journal of Applied Polymer Science. 52:591-596 |
| ISSN: | 1097-4628 0021-8995 |
| Popis: | Nucleating agents increase the impact strength, tensile strength, and tensile elasticity modulus of semicrystalline polymers. Nucleating agents also decrease product cycle times, resulting in a cost savings per product unit. We have synthesized and tested 15 compounds as nucleactors for polypropylene. Of these, trinapthylidene sorbitol, tri-(4-methyl-1-naphthylidene)sorbitol, tri-(4-methoxy-1-naphthylidene) sorbitol, and dibenzylidene xylitol are efficient nucleators of polypropylene. Trinaphthylidene sorbitol (tns) has two major diastereomers: The “S” diastereomer yields a faster crystallization rate for polypropylene than does the commercial nucleator dibenzylidene sorbitol (Millad 3905). Crystallization rates are 208 and 88, respectively (t min−1 × 1000). The “R” diastereomer, however, is a poor nucleator and interferes with the nucleating activity of the “S” diastereomer. A 52/48 mixture of diastereomers does not nucleate polypropylene, even at twice the concentration. This is first time that the importance of stereochemistry has been demonstrated in the nucleating action. © 1994 John Wiley & Sons, Inc. |
| Databáze: | OpenAIRE |
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