6. POLYESTERAMIDES Introduction: -Structure of Polyesteramides- Polyesteramides are group of biodegradable polymer that covers both specialties in the biomedical field and commodity applications. These polymers have amide and ester groups on their chemical structure which give good thermal and mechanical properties. Polyesteramides are polymers with hydrolysable backbones which able to biodegrade under particular conditions. Strong hydrogen bonding interactions between amide groups back up some typical weakness of aliphatic polyester.
INTRODUCTION: Lipase also called as triacylglycerol acylhydrolaseis an enzyme known for its enormous applications for industry and diagnostics. Their basic activity is to convert fats into fatty acids and glycerol. These enzymes are water soluble in nature. They also convert polar solvents into more lipolytic substances. In 1856, a scientist name claude Bernard has identified lipase .
Polyester is synthetic fiber which mainly derive organic chemical compound from coal, air, water and petroleum and have the ester linkage. According to How (2015), the chemical reaction between an acid and alcohol formed polyester where a combination of two or more molecules form large molecule whose the structure repeats throughout its length. Researched by Smith (n.d) mentioned that production of polyester is by the chemical reaction of ethylene glycol with either terephthalic acid or its methyl ester in the presence of antimony catalyst to produce initially the monomer and low molecular mass oligomers. i. Starting from the acid: Direct esterification reaction.
One noticeable exception is the so-called “Atwal modification” of the Biginelli reaction. In this scheme, an enone(a) is first condensed with a suitable protected urea or thiourea derivative(b) under almost neutral conditions. Deprotection of the resulting 1,4-dihydropyrimidine(c) with HCl or TFA leads to the desired DHPMs.20 Scheme-3: Shutalev et al described another approach to DHPMs synthesis. This synthesis is based on the condensation of readily available R-tosylated (thio)ureas(a) with the enolates of acetoacetates or 1,3-dicarbonyl compounds. The resulting hexahydropyrimidines(b) need not to be isolated and can be converted directly into DHPMs.
The proportion of ungrafted SAN in the final product depends on the conditions used of the manufacture of ABS. There are many factors that can be modified to change the amount of grafted and ungrafted SAN. This factors include temperature, chain-transfer agent and content of rubber. The graft SAN involves a process of free radical polymerization
Acetobacter aceti has four subspecies which are aceti, orleanensis, xylinum and liquafaciens. Acetic acid bacteria are bacteria that derive their energy from the oxidation of ethanol to acetic acid during fermentation. These types of bacteria are found naturally, where ethanol is being formed as a result of yeast fermentation of sugars and plant carbohydrates. Acetic acid bacteria have important roles in food and beverage production, as well as in the bio production of industrial chemicals. Jonas and Farah (1997) stated that the gram negative bacterium Acetobacter xylinum is the most studied for its capacity to synthesis cellulose among other bacteria that can synthesis bacterial cellulose.
INTRODUCTION Enzymes are biological catalyst that alters the chemical reaction rate without itself being altered which reacts with the substrate and converts the enzyme substrate complex into different molecules – product. Enzyme plays the consequential role in functioning of life process such as for growth, digestion of nutrients, excretion of metabolic waste, energy provider to brain and muscles and thus directly or indirectly involved in every biological processing of life. Apart from numerous life functioning role, enzymes are also used in industry-oriented procedure such as for drug delivery in biomedical research, production of biodiesel in energy sector, production of jams and syrups in food industry, treatment of sewage in waste management
INTRODUCTION HPC is non ionic semisynthetic polymer. Hydroxypropyl cellulose is also commonly known as hydroxypropyl methylcellulose (HPMC) or hypromellose which is a coating agent and film-former and used as an inactive ingredient in the pharmaceutical industry. It has also been used as a rate-controlling polymer for sustained-release dose forms in pharmaceutical industry. CHEMISTRY HPC is an ether of cellulose. In HPC some of the hydroxyl groups in the repeating glucose units have been hydroxypropylated which forms -OCH2CH(OH)CH3 groups using propylene oxide.
To indicate the separation effect for different ratio of p-xylene to methyl acetate more clearly, Fig. 4 shows the dependence of selectivity on the water/acetic acid mass ratio in the initial mixture for various different ratios of p-xylene to methyl acetate in the initial mixture. These results reveal the general capability of mixed solvent to extract acetic acid from the aqueous phase at different feed composition. As mentioned earlier, methyl acetate has been put up in this industrial operation, since it was available as the byproduct of terephthalic acid production. As can be seen in Fig.4, a higher ratio of p-xylene to methyl acetate can produce higher selectivity of acetic acid against water.
1.1. Polyesters Polyesters are the polymers that contain ester functional group in their main chain. The polyesters can be classified according to the composition of their main chain as aliphatic and semi-aromatic in addition to aromatic polyesters. Also can be thermoplastic or perhaps thermoses. All common polyesters are thermoplastics (Rosato, L. et al.