Synthetic polymers

Xem 1-14 trên 14 kết quả Synthetic polymers
  • New approaches to tailor-made cellulose/starch/lignin-synthetic polymer graft copolymers with precise control over molecular weight, degree of substitution, backbone-graft linkage, and the overall grafting process are being studied. Cross-linked graft copolymers with exactly defined polymer chain segments between crosslink points have been prepared. The graft copolymers exhibit a two-phase morphology and can function effectively as compatibilizers/interfacial agents to alloy cellulosic and lignocellulosic materials with synthetic polymers.

    pdf198p dontetvui 21-01-2013 35 20   Download

  • Synthetic polymers fulfill many functions in biotechnology and medicine. In cell culture technology and tissue engineering they provide the surfaces to which cells may attach. Cross-linked polymer networks are used for drug delivery and cell encapsulation. Polymer-based porous membranes can be used to shield implanted cells from the immune system of the host, while allowing for the exchange of nutrients and metabolic waste products thus keeping the cells alive and functioning.

    pdf171p camchuong_1 10-12-2012 35 7   Download

  • Synthetic polymers are essential for modern human life, since they are used in industrial and agricultural fields. However, most synthetic polymers that have been developed by using petroleum and coal as raw materials are not compatible with the environment, since they cannot be included in the natural recycling system. There are serious contradictions between the convenience that people require today and compatibility with the natural environment. It is easy to say that we should use only natural materials in order to solve the problems coming from man-made materials.

    pdf335p beobobeo 01-08-2012 35 13   Download

  • In this chapter, we discuss some of the fundamental principles of polymer chemistry. We begin with a survey of the different kinds of polymers, then consider the reactions used to induce polymerization. Finally, we discuss some of the structural characteristics that determine the physical properties of a polymer.

    ppt32p tangtuy02 11-03-2016 7 2   Download

  • Number of the equipments used in everyday life remarkably increased after the invention of synthetic polymers, especially of styrene-butadiene rubber in 1930 and of PVC in 1936, and thanks to fast-developing polymer technologies. Polymers are light, cheap and ductile inert materials, which have good mechanical and thermal properties, suitable to use for various purposes and are highly resistant to corrosion. Thanks to such properties, they play an essential and ubiquitous role in many industrial fields.

    pdf0p wqwqwqwqwq 06-07-2012 70 20   Download

  • Physical chemistry of macromolecules is a course that is frequently offered in the biochemistry curriculum of a college or university. Occasionally, it is also offered in the chemistry curriculum. When it is offered in the biochemistry curriculum, the subject matter is usually limited to biological topics and is identical to biophysical chemistry. When it is offered in the chemistry curriculum, the subject matter is often centered around synthetic polymers and the course is identical to physical polymer chemistry.

    pdf581p krac24 18-04-2013 50 17   Download

  • It is traditional to begin books about polyurethanes by defining the class of polymers that has come to be known as polyurethanes. Unlike olefin-based polymers (poly- ethylene, polypropylene, etc.), the uniqueness of polyurethane is that it results not from a specific monomer (ethylene, propylene, etc.), but rather from a type of reaction, specifically the formation of a specific chemical bond. Inevitably, the discussion in traditional books then progresses to the component parts, the produc- tion processes, and ultimately the uses.

    pdf181p layon_5 30-03-2013 21 9   Download

  • Scaffolds A scaffold provides a three-dimensional framework to support the tissue or organ-specific cells. The scaffold not only provides mechanical support, but it must also supply critical nutrients and transport metabolites to and from the developing tissue. Important scaffold properties vary depending on the tissue but typically include specific biomechanical properties, porosity, biocompatibility, and appropriate surface characteristics for cell adhesion and differentiation. Scaffolds can be natural materials or synthetic polymers and are typically biodegradable.

    pdf5p konheokonmummim 03-12-2010 41 5   Download

  • Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Protein-polymer nano-machines. Towards synthetic control of biological processes

    pdf7p toshiba25 08-12-2011 17 3   Download

  • Synthetic chemicals known as endocrine disruptors are an excellent example of emerging contaminants where the threats and consequences for water quality, human health, and the environment are still not fully understood. Endocrine disruptors – chemicals that can interfere with hormone action – have been identified among chemicals used in agriculture, industry, and households, and for personal care, including pesticides, disinfectants, plastic additives, and pharmaceuticals like birth control pills.

    pdf44p saimatkhauroi 01-02-2013 18 3   Download

  • The use of scientific techniques in materials conservation has notably expanded in recent decades. There is much interest in identifying the materials used in culturally important objects. Of great importance is a clear understanding of the state and mechanisms of degradation of objects susceptible to deterioration with time and exposure to environmental factors. An understanding of the state of materials at a molecular level can provide valuable information for conservators, enabling them to decide on a conservation procedure....

    pdf445p coeus75 29-01-2013 20 3   Download

  • Size-exclusion chromatography (SEC) separates polymer molecules and biomolecules based on differences in their molecular size. The separation process in simplified form is based on the ability of sample molecules to penetrate inside the pores of packing material and is dependent on the relative size of analyte molecules and the respective pore size of the absorbent. The process also relies on the absence of any interactions with the packing material surface. Two types of SEC are usually distinguished: 1.

    pdf17p bigbaby87 03-09-2010 54 19   Download

  • are not limited to: the wide range of oxidation and reduction reactions possible, the possibility of reaching very high levels of product purity and selectivity, and significantly less energy requirement. The process of electropolymerization leads to simple and reproducible formations of polymer films, which led to a broad material diversity of applications. Nowadays, electrochemistry plays an important role in a wide number of fundamental research and applied areas.

    pdf226p lulanphuong 22-03-2012 75 18   Download

  • Cationic cell wall-bound peroxidase (CWPO-C) has the capability to oxi-dize sinapyl alcohol, ferrocytochromec, and synthetic lignin polymers, unlike most peroxidases that have been characterized in flowering plants, such as horseradish peroxidase and Arabidopsis thalianaperoxidase A2.

    pdf10p cosis54 08-12-2012 11 1   Download

Đồng bộ tài khoản