Ravindra V. Gadhave, S. Srivastava, P. Mahanwar, P. Gadekar
{"title":"Recycling and Disposal Methods for Polyurethane Wastes: A Review","authors":"Ravindra V. Gadhave, S. Srivastava, P. Mahanwar, P. Gadekar","doi":"10.4236/OJPCHEM.2019.92004","DOIUrl":"https://doi.org/10.4236/OJPCHEM.2019.92004","url":null,"abstract":"Polyurethanes (PU) are a general class of polymers prepared by the polyaddition of isocyanates and hydroxyl group containing compounds. PU foams are formed via the reaction of poly-isocyanate and multi-functional hydroxyl compounds resulting in urethane linkages. The foams are formed in wide range of densities and maybe flexible, semi-flexible or rigid in structure. To control the foam structure, blowing agents are employed. These agents are introduced during foam formation through volatilization of low-boiling liquids or through the formation of gas due to chemical reaction. Additionally, surfactants, catalysts, etc. are used during the manufacturing of foams. PU, including PU foams, is one of the most important groups of materials today and hence, their recycling has been of great interest. Many methods of recycling PU are available and many more are being studied further. However, no method has seen large scale commercialization or is brought into regular practice. The objective of this review is to bring to light the various technologies available and their current status of development as well as newer upcoming methods that may be available in the future.","PeriodicalId":19592,"journal":{"name":"Open Journal of Polymer Chemistry","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91189216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ravindra V. Gadhave, S. Srivastava, P. Mahanwar, P. Gadekar
{"title":"Lignin: Renewable Raw Material for Adhesive","authors":"Ravindra V. Gadhave, S. Srivastava, P. Mahanwar, P. Gadekar","doi":"10.4236/OJPCHEM.2019.92003","DOIUrl":"https://doi.org/10.4236/OJPCHEM.2019.92003","url":null,"abstract":"Biobased raw material like lignin used during manufacturing of wood and wood composite adhesive have been used extensively to replaced petro-chemical based adhesive because of their easy availability, low cost and biodegradability. Bio-based resources, such as lignin which is an abundant, constitute a rich source of hydroxyl functionality which is being considered as reactive raw material for the production of “adhesives”. Lignin is mainly used for production of wood and wood composite adhesives by blending with soy protein, grafting with another polymer and reacting with isocynates. In this review, lignin as suitable alternative raw material to conventional petroleum sourced materials used as a raw material for adhesives is discussed.","PeriodicalId":19592,"journal":{"name":"Open Journal of Polymer Chemistry","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76097609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Study of Cross-Linking between Boric Acid and Different Types of Polyvinyl Alcohol Adhesive","authors":"Ravindra V. Gadhave, P. Mahanwar, P. Gadekar","doi":"10.4236/ojpchem.2019.91002","DOIUrl":"https://doi.org/10.4236/ojpchem.2019.91002","url":null,"abstract":"Polyvinyl alcohol (PVA) is water-soluble polymer manufactured by the saponification of polyvinyl acetate. The physical properties and its specific application depend on the degree of hydrolysis. To enhance the properties of different hydrolyzed PVA grades, it is generally chemically modified with various cross-linkers. Here, different degree hydrolyzed PVA grades with enhanced properties were achieved by cross-linking with boric acid. These samples were then characterized by Differential Scanning Calorimetry (DSC) and Gel permeation chromatography (GPC). For further analysis a film of samples were prepared by casting on glass plate. The effects of amount of boric acid and degree of hydrolysis of PVA on performance properties like tensile strength, pencil hardness and thermal properties like glass transition temperature were studied. The results showed that by cross-linking there was an increase in mechanical strength and thermal property.","PeriodicalId":19592,"journal":{"name":"Open Journal of Polymer Chemistry","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82527175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Phiriyawirut, K. Sarapat, S. Sirima, Anrasee Prasertchol
{"title":"Porous Electrospun Nanofiber from Biomass-Based Polyester Blends of Polylactic Acid and Polybutylene Succinate","authors":"M. Phiriyawirut, K. Sarapat, S. Sirima, Anrasee Prasertchol","doi":"10.4236/ojpchem.2019.91001","DOIUrl":"https://doi.org/10.4236/ojpchem.2019.91001","url":null,"abstract":"We studied the electrospinning process of the blend of polylactic acid (PLA) and polybutylene succinate (PBS). The blend PLA/PBS ratio 95/5, 90/10, 85/15 and 80/20 wt% were prepared by dissolved in mixture of solvent between dichloromethane (DCM) and N, N-dimethylformamide (DMF) at ratio 3/1. The suitable condition for electrospun of the blend was 17% wt concentration, 16 kV and 18 cm projection distance. The round fiber with pore on the surface was observed. Increasing content of PBS in the blend impact to the diameter of fibril decreased from 1350, 1290, 1210 and 1170 nm, respectively; while the pore on the surface changes from circle to oval shape. Regarding the thermal properties, blending of PBS increases the glass transition temperature (Tg) of PLA without affect to the melting temperature (Tm) of the electrospun nanofibers. The best tensile properties of PLA/PBS nanofibers were achieved at blend ratio of 95/5, and Young’s modulus is increased comparing to those of the pure electrospun fibers.","PeriodicalId":19592,"journal":{"name":"Open Journal of Polymer Chemistry","volume":"49 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91435872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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