Dimers (chemistry) 1970-01-01
In chemistry, a dimmer typically refers to a molecule that is formed by the combination of two identical or similar monomer units. This dimerization process can occur through various types of chemical bonding, including covalent bonds, hydrogen bonds, or ionic interactions.
Fiberglass 1970-01-01
Fiberglass, or glass-reinforced plastic (GRP), is a composite material consisting of a plastic matrix reinforced with fine glass fibers. It is known for its high strength-to-weight ratio, resistance to corrosion, and durability, making it a popular choice in various applications. ### Composition: - **Fibers**: Made from glass, these fibers give the material strength and rigidity.
Monomers 1970-01-01
Monomers are small, simple molecules that can join together to form larger and more complex structures known as polymers. The process of linking monomers together is called polymerization. Monomers can be organic compounds, such as those containing carbon, or inorganics, such as silicates. Common examples of monomers include: 1. **Glucose** - a simple sugar that can polymerize to form starch or cellulose.
Oligomers 1970-01-01
Oligomers are short chains of monomers, which are small, repeating units that can combine to form larger molecules known as polymers. In chemistry, oligomers typically consist of a limited number of monomer units, generally ranging from two to around ten or twenty. They can be formed from various types of monomers, including sugars, amino acids, and other organic compounds. Oligomers can have distinct physical and chemical properties compared to their corresponding polymers.
Organic solar cells 1970-01-01
Organic solar cells (OSCs) are a type of photovoltaic technology that uses organic molecules, typically carbon-based compounds, to convert sunlight into electricity. Unlike traditional solar cells that are based on inorganic materials such as silicon, organic solar cells utilize organic semiconductors, which can be small organic molecules or polymers. **Key Features of Organic Solar Cells:** 1. **Materials**: They are made from organic materials, including conjugated polymers and small organic molecules.
Polymer science journals 1970-01-01
Polymer science journals are academic publications that focus on research related to polymers, which are large molecules made up of repeating structural units (monomers). These journals cover a wide range of topics within the field of polymer science, including: 1. **Polymer Chemistry**: Studies related to the synthesis and characterization of polymers, including novel polymerization techniques and the development of new monomers.
Polymerization reactions 1970-01-01
Polymerization reactions are chemical processes in which small molecules called monomers link together to form larger, more complex structures known as polymers. This process is fundamental in the creation of a wide variety of materials, including plastics, rubbers, fibers, and more. There are two primary types of polymerization reactions: 1. **Addition Polymerization (Chain-Growth Polymerization)**: In this type, the monomers contain double bonds or other reactive functional groups that can react to form long chains.
Polymers 1970-01-01
Polymers are large molecules composed of repeating structural units called monomers, which are covalently bonded together. The process of forming polymers from monomers is known as polymerization. Polymers can be naturally occurring or synthetic, and they play vital roles in both biological systems and industrial applications.
Radical initiators 1970-01-01
Radical initiators are compounds that generate free radicals when subjected to certain conditions, such as heat, light, or chemical reactions. Free radicals are highly reactive species with unpaired electrons that can initiate a chain reaction, commonly utilized in various chemical processes, such as polymerization. In radical polymerization, radical initiators are used to start the polymerization process of monomers, leading to the formation of polymers.
Addition polymer 1970-01-01
Addition polymers are a type of polymer that are formed through a process called addition polymerization, in which monomers (small, reactive molecules) are joined together without the loss of any small molecules (such as water or gas). This process typically involves unsaturated monomers, which contain double bonds (e.g., alkenes). In addition polymerization, the double bonds in the monomers open up and link together to form long chains, resulting in the formation of high molecular weight polymers.
Autoacceleration 1970-01-01
Autoacceleration typically refers to a phenomenon where processes or systems increase their own rate of acceleration without external input. This concept may be found in various contexts, including: 1. **Physics**: In a physical context, autoacceleration might describe an object that continues to accelerate due to its own properties or internal forces, such as gravity acting on a falling object.
Bioplastic 1970-01-01
Bioplastic refers to a type of plastic that is either made from renewable biomass sources, such as plant materials, or is designed to biodegrade more easily than traditional plastics. There are two main categories of bioplastics: 1. **Bio-based Plastics**: These are primarily made from renewable resources like starch, cellulose, or polylactic acid (PLA) derived from corn or sugarcane.
Bloom (phase) 1970-01-01
The term "Bloom" can refer to different concepts depending on the context. If you are referring to "Bloom's Taxonomy," it is an educational framework used to classify learning objectives and goals in education. Created by Benjamin Bloom in 1956, the taxonomy is divided into three domains: cognitive, affective, and psychomotor.
Branching (polymer chemistry) 1970-01-01
In polymer chemistry, "branching" refers to the presence of side chains or branches that extend from the main backbone of a polymer molecule. This structural feature can significantly influence the physical and chemical properties of the polymer. Here are some key points regarding branching: 1. **Types of Branching**: - **Linear Polymers**: These consist of long, straight chains without any branches.
Brinkman number 1970-01-01
The Brinkman number (Br) is a dimensionless quantity in fluid mechanics and heat transfer that characterizes the relative importance of viscous dissipation to thermal conduction in a fluid flow. It is commonly used in the study of flow in porous media or in situations where the flow is significantly affected by both viscous forces and thermal effects.
Carothers equation 1970-01-01
Carothers' equation is a mathematical expression used in the field of polymer chemistry to describe the molecular weight of a polymer formed through step-growth polymerization. Specifically, it relates the degree of polymerization (DP) to the extent of reaction (p) of the monomers involved in the polymerization process.
Catalytic chain transfer 1970-01-01
Catalytic chain transfer is a process that occurs during the polymerization of certain monomers, particularly in free radical polymerizations. This mechanism involves the transfer of a growing polymer chain from one polymer radical to another, effectively controlling the molecular weight and structure of the resulting polymer. In catalytic chain transfer, a catalyst or transfer agent facilitates the transfer of the growing chain end to a new center, which can be another growing polymer chain or a small molecule.
Ceiling temperature 1970-01-01
Ceiling temperature typically refers to the maximum temperature that can be achieved or maintained within a specific context, such as in a thermal environment, an experimental setup, or industrial processes. It is relevant in various fields, including meteorology, HVAC (heating, ventilation, and air conditioning), and materials science. 1. **Meteorology**: In weather reporting, "ceiling" often describes the height of the lowest layer of clouds or obscuring phenomena above the Earth's surface.
Chain-growth polymerization 1970-01-01
Chain-growth polymerization, also known as chain reaction polymerization, is a method of synthesizing polymers in which the structure of the polymer grows by the sequential addition of monomer units. This process typically involves three main steps: initiation, propagation, and termination. 1. **Initiation**: This step begins with the formation of reactive species, such as free radicals, cations, or anions, which are necessary to initiate the polymerization process.
Chain propagation 1970-01-01
Chain propagation typically refers to a process in various fields, but it most commonly relates to the spreading of effects or signals through a system or network. Depending on the context, it could have specific meanings: 1. **Communications and Signal Processing**: In these fields, chain propagation may describe how signals are transmitted through multiple stages or components in a network. Each stage can affect the quality and characteristics of the signal as it propagates through the system.