H. Fink - Academia.edu (original) (raw)
Papers by H. Fink
Handbook of Textile Fibre Structure, 2009
Carbohydrate Polymers, 2016
Presented study deals with the pre-treatment of cellulose fibres with the aim to activate their s... more Presented study deals with the pre-treatment of cellulose fibres with the aim to activate their surface and to enlarge their pore system, leading to an enhancement of fibres' affinity for subsequent functionalization processes. Swelling of fibres in aqueous solutions of sodium hydroxide opens their fibrillar structure, while freezing and freeze-drying retain this enlargement of the pore system, in contrast with conventional air or elevated temperature drying. Effect of different pre-treatment procedures on fibres' supramolecular structure, enlargement of their pore system, surface topography, zeta potential and mechanical properties was investigated. Degree of enhancement of the pore system depends on the concentration of sodium hydroxide and type of freezing; higher alkali concentrations are more effective, but at the cost of extensive deterioration of mechanical properties. Swelling of fibres in lower concentrations of NaOH, in combination with freeze drying, offers an acceptable compromise between enhancement of the fibres' pore system, changes in surface potential and tensile properties of treated fibres. Design of a suitable regime of swelling and drying of cellulose fibres results in an effective procedure for controlled tuning of their surface topography in combination with an increase of the available internal surface area and pore volume.
Kunststoffe International
The article also introduces a new generation of cellulose-fiber-reinforced PLA compounds, charact... more The article also introduces a new generation of cellulose-fiber-reinforced PLA compounds, characterized by exceptionally high impact strength. The enormous improvement in this property is due solely to the change in fiber-matrix interaction, which can be adjusted without any problem by incorporating suitable additives during compounding. Producing and Testing Compounds The matrix material used was a type 4042D PLA, optimized for film production, with a molecular weight M w of 170,000 g/mol, a D-lactic acid content of 8 %, a melt flow index (MFI) of 18 g/10 min (2.16 kg, 210°C) and a density of 1.25 g/cm 3 (manufacturer: Nature-Works LLC). For the reinforcing material, type RT 700 high-tenacity cellulose fibers were chosen (manufacturer: Cordenka GmbH). These high-performance cellulose fibers, which are normally used as rayon tire cord in high-speed tires, have high values for strength (885 MPa), stiffness (19.5 GPa) and elongation at break Cellulose fibers are highly efficient reinforcing materials for bioplastics (all sources: IAP)
Polymer, 1998
Native cellulose, especially ground cotton linters, was step-by-step carboxymethylated in alcohol... more Native cellulose, especially ground cotton linters, was step-by-step carboxymethylated in alcohol-water medium at low concentrations of NaOH. Using the 13 C cross-polarization/magic angle spinning nmr method, it has been found that, under these conditions, initially the ...
Polymer, 1986
A concept of reacting structural fractions is presented to discuss NaOH-and H 2 O-sorption of cel... more A concept of reacting structural fractions is presented to discuss NaOH-and H 2 O-sorption of cellulose up to a lye concentration of 18% NaOH. The reacting structural fraction has been estimated by wide-angle X-ray scattering combined with a consistent application of a two-phase ...
* This work was presented during the 9th European Workshop on Lignocellulosics and Pulp (EWLP) 28... more * This work was presented during the 9th European Workshop on Lignocellulosics and Pulp (EWLP) 28 th-30 th August, Vienna, Austria Fiber properties (tenacity, elongation, and modulus) of man-made cellulose fibers are depending on their inner structure. Changes in fiber structure result in changes in fiber properties and vice versa. The crystallinity is one of these structural parameters. Native cellulose (e.g., wood, pulp, cotton, kenaf, bacteria cellulose) consists of the cellulose I, regenerated cellulose consists of the cellulose II modification. WAXS (wide angle X-ray scattering) is the standard method for the determination of crystallinity of manmade cellulose fibers. This method was established by Hermans and Weidinger in 1949 [1]. Nowadays the information concerning crystallinity of cellulose II can be obtained by other methods as well, e.g. Fourier Transform (FT) Raman, FTinfrared (IR), or solid state 13 C NMR (nuclear magnetic resonance) Spectroscopy. An extensive matrix of cellulose II samples from different sources was investigated using the methods mentioned above. The results were compared with those of the standard WAXS method.
Nano- and Biocomposites, 2009
Materials and Applications, 2013
Cellulose Fibers: Bio- and Nano-Polymer Composites, 2011
This paper gives an overview of our recent research activities on the lateral supramolecular orde... more This paper gives an overview of our recent research activities on the lateral supramolecular order of a variety of native and man-made cellulosics considering respective results from the literature. Wide-angle X-ray scattering (WAXS) was the main investigation technique used. Lateral root mean squared lattice strains between 2 and 3% were determined for the materials investigated. Crystallite sizes obtained without considering
Progress in Polymer Science, 2012
ABSTRACT Due to environment and sustainability issues, this century has witnessed remarkable achi... more ABSTRACT Due to environment and sustainability issues, this century has witnessed remarkable achievements in green technology in the field of materials science through the development of biocomposites. The development of high-performance materials made from natural resources is increasing worldwide. The greatest challenge in working with natural fiber reinforced plastic composites is their large variation in properties and characteristics. A biocomposite's properties are influenced by a number of variables, including the fiber type, environmental conditions (where the plant fibers are sourced), processing methods, and any modification of the fiber. It is also known that recently there has been a surge of interest in the industrial applications of composites containing biofibers reinforced with biopolymers. Biopolymers have seen a tremendous increase in use as a matrix for biofiber reinforced composites. A comprehensive review of literature (from 2000 to 2010) on the mostly readily utilized natural fibers and biopolymers is presented in this paper. The overall characteristics of reinforcing fibers used in biocomposites, including source, type, structure, composition, as well as mechanical properties, will be reviewed. Moreover, the modification methods; physical (corona and plasma treatment) and chemical (silane, alkaline, acetylation, maleated coupling, and enzyme treatment) will be discussed. The most popular matrices in biofiber reinforced composites based on petrochemical and renewable resources will also be addressed. The wide variety of biocomposite processing techniques as well as the factors (moisture content, fiber type and content, coupling agents and their influence on composites properties) affecting these processes will be discussed. Prior to the processing of biocomposites, semi-finished product manufacturing is also vital, which will be illustrated. Processing technologies for biofiber reinforced composites will be discussed based on thermoplastic matrices (compression molding, extrusion, injection molding, LFT-D-method, and thermoforming), and thermosets (resin transfer molding, sheet molding compound). Other implemented processes, i.e., thermoset compression molding and pultrusion and their influence on mechanical performance (tensile, flexural and impact properties) will also be evaluated. Finally, the review will conclude with recent developments and future trends of biocomposites as well as key issues that need to be addressed and resolved.
Polymer, 1987
The structure of amorphized cellulose samples prepared by ball milling of cellulose I and II and ... more The structure of amorphized cellulose samples prepared by ball milling of cellulose I and II and by saponification of cellulose triacetate is investigated by means of radial distribution functions (RDFs). Experimental wide-angle X-ray scattering results are compared with model ...
Polimery, 2013
Niniejszy zeszyt "Polimerów" jest pooewiêcony kompozytom polimerowym. Zespó³ redakcyjny serdeczni... more Niniejszy zeszyt "Polimerów" jest pooewiêcony kompozytom polimerowym. Zespó³ redakcyjny serdecznie dziêkuje Panu prof. dr. hab. in¿. Andrzejowi K. B³êdzkiemu za inicjatywê wydania tego zeszytu oraz za cenn¹ pomoc merytoryczn¹ w jego przygotowaniu.
Macromolecular Symposia, 2005
Macromol. Symp. 2005, 223, 175-187 175 Structural Changes and Activation of Cellulose by Caustic ... more Macromol. Symp. 2005, 223, 175-187 175 Structural Changes and Activation of Cellulose by Caustic Soda Solution with Urea Jürgen Kunze, Hans-Peter Fink* Fraunhofer-Institute for Applied Polymer Research, Geiselbergstrasse 69, 14476 Potsdam-Golm, Germany Fax: (+49) ...
Macromolecular Symposia, 2008
Summary: Highly porous cellulose was formed by gelation of cellulose carbamate solutions in caust... more Summary: Highly porous cellulose was formed by gelation of cellulose carbamate solutions in caustic soda. Two methods for gel preparation were optimized for the formation of beads and bulky materials the chemical precipitation from dilute sulfuric acid and the thermal ...
Macromolecular Symposia, 2006
Summary: A new class of fibre reinforced commodity thermoplastics suited for injection moulding a... more Summary: A new class of fibre reinforced commodity thermoplastics suited for injection moulding and direct processing applications has been developed using man-made cellulosic fibres (Rayon tire yarn, Tencel, Viscose, Carbacell) and thermoplastic ...
Macromolecular Materials and Engineering, 2001
Separated amyloses with different molecular weight distributions were obtained enzymatically from... more Separated amyloses with different molecular weight distributions were obtained enzymatically from wrinkled pea starch and processed in a multi-zone twin-screw extruder. The crystalline polymorphs, crystallinity and crystallite dimensions of amylose (unbranched molecular ...
Handbook of Textile Fibre Structure, 2009
Carbohydrate Polymers, 2016
Presented study deals with the pre-treatment of cellulose fibres with the aim to activate their s... more Presented study deals with the pre-treatment of cellulose fibres with the aim to activate their surface and to enlarge their pore system, leading to an enhancement of fibres' affinity for subsequent functionalization processes. Swelling of fibres in aqueous solutions of sodium hydroxide opens their fibrillar structure, while freezing and freeze-drying retain this enlargement of the pore system, in contrast with conventional air or elevated temperature drying. Effect of different pre-treatment procedures on fibres' supramolecular structure, enlargement of their pore system, surface topography, zeta potential and mechanical properties was investigated. Degree of enhancement of the pore system depends on the concentration of sodium hydroxide and type of freezing; higher alkali concentrations are more effective, but at the cost of extensive deterioration of mechanical properties. Swelling of fibres in lower concentrations of NaOH, in combination with freeze drying, offers an acceptable compromise between enhancement of the fibres' pore system, changes in surface potential and tensile properties of treated fibres. Design of a suitable regime of swelling and drying of cellulose fibres results in an effective procedure for controlled tuning of their surface topography in combination with an increase of the available internal surface area and pore volume.
Kunststoffe International
The article also introduces a new generation of cellulose-fiber-reinforced PLA compounds, charact... more The article also introduces a new generation of cellulose-fiber-reinforced PLA compounds, characterized by exceptionally high impact strength. The enormous improvement in this property is due solely to the change in fiber-matrix interaction, which can be adjusted without any problem by incorporating suitable additives during compounding. Producing and Testing Compounds The matrix material used was a type 4042D PLA, optimized for film production, with a molecular weight M w of 170,000 g/mol, a D-lactic acid content of 8 %, a melt flow index (MFI) of 18 g/10 min (2.16 kg, 210°C) and a density of 1.25 g/cm 3 (manufacturer: Nature-Works LLC). For the reinforcing material, type RT 700 high-tenacity cellulose fibers were chosen (manufacturer: Cordenka GmbH). These high-performance cellulose fibers, which are normally used as rayon tire cord in high-speed tires, have high values for strength (885 MPa), stiffness (19.5 GPa) and elongation at break Cellulose fibers are highly efficient reinforcing materials for bioplastics (all sources: IAP)
Polymer, 1998
Native cellulose, especially ground cotton linters, was step-by-step carboxymethylated in alcohol... more Native cellulose, especially ground cotton linters, was step-by-step carboxymethylated in alcohol-water medium at low concentrations of NaOH. Using the 13 C cross-polarization/magic angle spinning nmr method, it has been found that, under these conditions, initially the ...
Polymer, 1986
A concept of reacting structural fractions is presented to discuss NaOH-and H 2 O-sorption of cel... more A concept of reacting structural fractions is presented to discuss NaOH-and H 2 O-sorption of cellulose up to a lye concentration of 18% NaOH. The reacting structural fraction has been estimated by wide-angle X-ray scattering combined with a consistent application of a two-phase ...
* This work was presented during the 9th European Workshop on Lignocellulosics and Pulp (EWLP) 28... more * This work was presented during the 9th European Workshop on Lignocellulosics and Pulp (EWLP) 28 th-30 th August, Vienna, Austria Fiber properties (tenacity, elongation, and modulus) of man-made cellulose fibers are depending on their inner structure. Changes in fiber structure result in changes in fiber properties and vice versa. The crystallinity is one of these structural parameters. Native cellulose (e.g., wood, pulp, cotton, kenaf, bacteria cellulose) consists of the cellulose I, regenerated cellulose consists of the cellulose II modification. WAXS (wide angle X-ray scattering) is the standard method for the determination of crystallinity of manmade cellulose fibers. This method was established by Hermans and Weidinger in 1949 [1]. Nowadays the information concerning crystallinity of cellulose II can be obtained by other methods as well, e.g. Fourier Transform (FT) Raman, FTinfrared (IR), or solid state 13 C NMR (nuclear magnetic resonance) Spectroscopy. An extensive matrix of cellulose II samples from different sources was investigated using the methods mentioned above. The results were compared with those of the standard WAXS method.
Nano- and Biocomposites, 2009
Materials and Applications, 2013
Cellulose Fibers: Bio- and Nano-Polymer Composites, 2011
This paper gives an overview of our recent research activities on the lateral supramolecular orde... more This paper gives an overview of our recent research activities on the lateral supramolecular order of a variety of native and man-made cellulosics considering respective results from the literature. Wide-angle X-ray scattering (WAXS) was the main investigation technique used. Lateral root mean squared lattice strains between 2 and 3% were determined for the materials investigated. Crystallite sizes obtained without considering
Progress in Polymer Science, 2012
ABSTRACT Due to environment and sustainability issues, this century has witnessed remarkable achi... more ABSTRACT Due to environment and sustainability issues, this century has witnessed remarkable achievements in green technology in the field of materials science through the development of biocomposites. The development of high-performance materials made from natural resources is increasing worldwide. The greatest challenge in working with natural fiber reinforced plastic composites is their large variation in properties and characteristics. A biocomposite's properties are influenced by a number of variables, including the fiber type, environmental conditions (where the plant fibers are sourced), processing methods, and any modification of the fiber. It is also known that recently there has been a surge of interest in the industrial applications of composites containing biofibers reinforced with biopolymers. Biopolymers have seen a tremendous increase in use as a matrix for biofiber reinforced composites. A comprehensive review of literature (from 2000 to 2010) on the mostly readily utilized natural fibers and biopolymers is presented in this paper. The overall characteristics of reinforcing fibers used in biocomposites, including source, type, structure, composition, as well as mechanical properties, will be reviewed. Moreover, the modification methods; physical (corona and plasma treatment) and chemical (silane, alkaline, acetylation, maleated coupling, and enzyme treatment) will be discussed. The most popular matrices in biofiber reinforced composites based on petrochemical and renewable resources will also be addressed. The wide variety of biocomposite processing techniques as well as the factors (moisture content, fiber type and content, coupling agents and their influence on composites properties) affecting these processes will be discussed. Prior to the processing of biocomposites, semi-finished product manufacturing is also vital, which will be illustrated. Processing technologies for biofiber reinforced composites will be discussed based on thermoplastic matrices (compression molding, extrusion, injection molding, LFT-D-method, and thermoforming), and thermosets (resin transfer molding, sheet molding compound). Other implemented processes, i.e., thermoset compression molding and pultrusion and their influence on mechanical performance (tensile, flexural and impact properties) will also be evaluated. Finally, the review will conclude with recent developments and future trends of biocomposites as well as key issues that need to be addressed and resolved.
Polymer, 1987
The structure of amorphized cellulose samples prepared by ball milling of cellulose I and II and ... more The structure of amorphized cellulose samples prepared by ball milling of cellulose I and II and by saponification of cellulose triacetate is investigated by means of radial distribution functions (RDFs). Experimental wide-angle X-ray scattering results are compared with model ...
Polimery, 2013
Niniejszy zeszyt "Polimerów" jest pooewiêcony kompozytom polimerowym. Zespó³ redakcyjny serdeczni... more Niniejszy zeszyt "Polimerów" jest pooewiêcony kompozytom polimerowym. Zespó³ redakcyjny serdecznie dziêkuje Panu prof. dr. hab. in¿. Andrzejowi K. B³êdzkiemu za inicjatywê wydania tego zeszytu oraz za cenn¹ pomoc merytoryczn¹ w jego przygotowaniu.
Macromolecular Symposia, 2005
Macromol. Symp. 2005, 223, 175-187 175 Structural Changes and Activation of Cellulose by Caustic ... more Macromol. Symp. 2005, 223, 175-187 175 Structural Changes and Activation of Cellulose by Caustic Soda Solution with Urea Jürgen Kunze, Hans-Peter Fink* Fraunhofer-Institute for Applied Polymer Research, Geiselbergstrasse 69, 14476 Potsdam-Golm, Germany Fax: (+49) ...
Macromolecular Symposia, 2008
Summary: Highly porous cellulose was formed by gelation of cellulose carbamate solutions in caust... more Summary: Highly porous cellulose was formed by gelation of cellulose carbamate solutions in caustic soda. Two methods for gel preparation were optimized for the formation of beads and bulky materials the chemical precipitation from dilute sulfuric acid and the thermal ...
Macromolecular Symposia, 2006
Summary: A new class of fibre reinforced commodity thermoplastics suited for injection moulding a... more Summary: A new class of fibre reinforced commodity thermoplastics suited for injection moulding and direct processing applications has been developed using man-made cellulosic fibres (Rayon tire yarn, Tencel, Viscose, Carbacell) and thermoplastic ...
Macromolecular Materials and Engineering, 2001
Separated amyloses with different molecular weight distributions were obtained enzymatically from... more Separated amyloses with different molecular weight distributions were obtained enzymatically from wrinkled pea starch and processed in a multi-zone twin-screw extruder. The crystalline polymorphs, crystallinity and crystallite dimensions of amylose (unbranched molecular ...