Karl-Heinz Dr. Ott

Bio: Karl-Heinz Dr. Ott is an academic researcher from Bayer. The author has contributed to research in topics: Thermoplastic & Copolymer. The author has an hindex of 24, co-authored 325 publications receiving 2803 citations.

ABS moulding compositions

Abstract: This invention relates to thermoplastic moulding compositions of the ABS-type produced in emulsion and having improved properties in relation to known ABS-moulding compositions, particularly extreme toughness coupled with ready processibility and high surface gloss.

Flame-retardant, high-impact polycarbonate molding compounds

Abstract: The invention relates to polycarbonate molding compounds consisting of halogen-free polycarbonates, graft polymers, phosphorus compounds, tetrafluoroethylene polymers and, optionally, copolymers and/or, optionally, other additives known per se and a process for their production.

Thermoplastic molding material

Abstract: PURPOSE: To obtain a molding material which does not discolor during molding and has good heat stability and surface properties by using a mixture comprising a thermoplastic aromatic polycarbonate, etc., a graft copolymer obtained by emulsion polymerization in the presence of a specified emulsifier and a thermoplastic vinyl copolymer. CONSTITUTION: This material is obtained by mixing 95-10 wt.% thermoplastic vinyl copolymer of a mixture of several aromatic polycarbonates with 5-90 wt.% mixture comprising 100-0 pts.wt. graft polymer prepared by melting 1 mol of a diol corresponding to formula I (wherein M is a group of any one of formulas II to IV) and 2 mol of a carboxylic acid anhydride corresponding to formula VI (wherein R 1 and R 3 are each H, a 1-36C alkyl or the like; R 2 and R 4 are each H, R 1 and R 4 may be combined to form a chemical bond; R 2 and R 3 together with the carbon atoms to which they are bonded may form o-phenylene; and (x) is 0 or 1) or formula VI (wherein Y is a group of formula VII or VIII or the like) together at 100-300°C in an inert gas and emulsion- polymerizing the melt in the presence of an emulsifier converted into e.g. an alkali metal salt. COPYRIGHT: (C)1991,JPO

Graft polymers and their mixtures with polyamides

Abstract: Pfropfpolymerisate hergestellt aus 1. einer Elastomerkomponente mit Gasubergangstemperaturen <0°C als Pfropfgrundlage und 2. Pfropfmonomeren der allgemeinen Formel (I) worin R' = H oder einen C 1 -C 4 Alkylrest, R 3 = H, Phenyl- oder einen C 1 -C 8 -Alkylrest, R 2 = H, einen C 1 -C 10 -Alkyl-, C 6 -C 12 -Arylrest oder -OR 4 mit R 4 ein C 1 -C 8 -Alkyl- oder C 6 -C 12 -Arylrest, der gegebenenfalls mit Alkyl-, O- oder N-hattigen Gruppen substituiert sein kann, X=eine Einfachbindung, einen C 1 -C 10 -Alkylen-, C 6 -C 12 -Arylen oder -rest bedeuten mit Y =-OZ-, -NH-Z und Z = ein C 1 -C 10 -Alkylen- oder C 6 -C 12 -Arylenrest und gegebenenfalls weiteren olefinisch ungesattigten Monomeren.

Polystyrene and Styrene Copolymers

Abstract: The article contains sections titled: 1. Polystyrene 1.1. Introduction 1.2. Production 1.2.1. Bulk Polymerization 1.2.2. Suspension Polymerization 1.3. Properties 1.3.1. Chemical Properties 1.3.2. Physical and Processing Properties 1.4. Processing and Uses 1.5. Quality Specifications 1.6. Storage and Transportation 1.7. Recycling 1.8. Environmental Aspects 1.9. Economic Aspects 2. Styrene - Acrylonitrile (SAN) Copolymers 2.1. Production 2.2. Properties 2.3. Processing 2.4. Uses and Economic Aspects 2.5. Blending of SAN 3. Barrier Resins 4. Other Copolymers 4.1. α-Methylstyrene - Acrylonitrile Copolymers 4.2. Styrene - Methyl Methacrylate Copolymers 4.3. Styrene - Maleic Anhydride Copolymers 4.4. Styrene - Maleimide Copolymers 4.5. Styrene - Acrylate Copolymers 5. Acrylonitrile - Butadiene - Styrene (ABS) Polymers 5.1. Definition and Structure 5.1.1. Historical Aspects 5.1.2. Structural Principles 5.1.3. Synthesis of the Two-Phase Structure 5.1.4. Properties of the Resin Matrix 5.2. Structure - Property Relationships 5.3. Production of ABS Polymers 5.3.1. ABS Production by Emulsion Polymerization 5.3.2. Production of the Matrix Copolymer 5.3.3. ABS Production by Bulk Polymerization 5.3.4. Process Combinations 5.3.5. Other Processes 5.3.6. Additives 5.4. Quality Assurance and Standardization 5.5. Properties 5.6. Special Product Modifications 5.7. Legal Aspects 5.8. Storage and Transportation 5.9. Uses 5.10. Economic Aspects 5.11. Recycling 5.12. ABS-Analogous Systems 5.12.1. ASA, AES, and ACS Polymers 5.12.2. MBS and MABS Polymers 5.13. ABS Blends

Accumulation and Embryotoxicity of Polystyrene Nanoparticles at Early Stage of Development of Sea Urchin Embryos Paracentrotus lividus

Abstract: Nanoplastic debris, resulted from runoff and weathering breakdown of macro- and microplastics, represents an emerging concern for marine ecosystems. The aim of the present study was to investigate disposition and toxicity of polystyrene nanoparticles (NPs) in early development of sea urchin embryos (Paracentrotus lividus). NPs with two different surface charges where chosen, carboxylated (PS-COOH) and amine (PS-NH2) polystyrene, the latter being a less common variant, known to induce cell death in several in vitro cell systems. NPs stability in natural seawater (NSW) was measured while disposition and embryotoxicity were monitored within 48 h of postfertilization (hpf). Modulation of genes involved in cellular stress response (cas8, 14-3-3e, p-38 MAPK, Abcb1, Abcc5) was investigated. PS-COOH forms microaggregates (PDI > 0.4) in NSW, whereas PS-NH2 results are better dispersed (89 ± 2 nm) initially, though they also aggregated partially with time. Their respectively anionic and cationic nature was confirmed by ζ-potential measurements. No embryotoxicity was observed for PS-COOH up to 50 μg mL(-1) whereas PS-NH2 caused severe developmental defects (EC50 3.85 μg mL(-1) 24 hpf and EC50 2.61 μg mL(-1) 48 hpf). PS-COOH accumulated inside embryo's digestive tract while PS-NH2 were more dispersed. Abcb1 gene resulted up-regulated at 48 hpf by PS-COOH whereas PS-NH2 induced cas8 gene at 24 hpf, suggesting an apoptotic pathway. In line with the results obtained with the same PS NPs in several human cell lines, also in sea urchin embryos, differences in surface charges and aggregation in seawater strongly affect their embryotoxicity.

Plastics: Environmental and Biotechnological Perspectives on Microbial Degradation.

Abstract: Plastics are widely used in the global economy, and each year, at least 350 to 400 million tons are being produced. Due to poor recycling and low circular use, millions of tons accumulate annually in terrestrial or marine environments. Today it has become clear that plastic causes adverse effects in all ecosystems and that microplastics are of particular concern to our health. Therefore, recent microbial research has addressed the question of if and to what extent microorganisms can degrade plastics in the environment. This review summarizes current knowledge on microbial plastic degradation. Enzymes available act mainly on the high-molecular-weight polymers of polyethylene terephthalate (PET) and ester-based polyurethane (PUR). Unfortunately, the best PUR- and PET-active enzymes and microorganisms known still have moderate turnover rates. While many reports describing microbial communities degrading chemical additives have been published, no enzymes acting on the high-molecular-weight polymers polystyrene, polyamide, polyvinylchloride, polypropylene, ether-based polyurethane, and polyethylene are known. Together, these polymers comprise more than 80% of annual plastic production. Thus, further research is needed to significantly increase the diversity of enzymes and microorganisms acting on these polymers. This can be achieved by tapping into the global metagenomes of noncultivated microorganisms and dark matter proteins. Only then can novel biocatalysts and organisms be delivered that allow rapid degradation, recycling, or value-added use of the vast majority of most human-made polymers.

Antimicrobial properties of a novel silver-silica nanocomposite material.

Abstract: Nanotechnology enables development and production of novel silver-based composite materials. We used in vitro tests to demonstrate the antimicrobial activity of a silver-silica nanocomposite compared to the activities of conventional materials, such as silver nitrate and silver zeolite. A silver-silica-containing polystyrene material was manufactured and shown to possess strong antimicrobial properties.

Flame retardant compositions

Abstract: Organic polymer substrates, for example polyolefins such as polypropylene, can be made flame retardant by the incorporation of a mixture of (i) at least one melamine based flame retardant and (ii) at least one flame retardant selected from the group consisting of the organohalogen and phosphorus containing flame retardants. Further optional flame retardants include antimony compounds and sterically hindered amines.