Open Journal of Polymer Chemistry

Journal Information
ISSN / EISSN : 21656681 / 21656711
Current Publisher: Scientific Research Publishing, Inc, (10.4236)
Total articles ≅ 86
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Ravindra V. Gadhave, Shrray Srivastava, Prakash A. Mahanwar, Pradeep T. Gadekar
Open Journal of Polymer Chemistry, Volume 9, pp 39-51; doi:10.4236/ojpchem.2019.92004

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.
Manisara Phiriyawirut, Kanokwan Sarapat, Sutasinee Sirima, Anrasee Prasertchol
Open Journal of Polymer Chemistry, Volume 9, pp 1-15; doi:10.4236/ojpchem.2019.91001

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.
Ravindra V. Gadhave, Prakash A. Mahanwar, Pradeep T. Gadekar
Open Journal of Polymer Chemistry, Volume 9, pp 16-26; doi:10.4236/ojpchem.2019.91002

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.
Ravindra V. Gadhave, Praneeta Sheety, Prakash A. Mahanwar, Pradeep T. Gadekar, Bilvesh J. Desai
Open Journal of Polymer Chemistry, Volume 9, pp 53-62; doi:10.4236/ojpchem.2019.93005

Abstract:Currently there has been a growing interest in substituting traditional synthetic polymers with biobased renewable polymers for adhesive applications. However, biobased renewable polymers such as starch suffer from few draw-backs like poor water resistance and mechanical strength. To become important potential alternatives of synthetic polymers, starch must have comparable physical, chemical, thermal and mechanical properties to that of synthetic polymers. To achieve this, starch has been modified by a series of crosslinkers like boric acid, citric acid, glyoxal, gluteraldehyde, etc. and silane modification. Silane modification by chloropropyl trimethoxysilane, γ-Methacryloxypropyl trimethoxy silane and vinyl trimethoxy silane is a suitable method to improve the performance in terms of mechanical and thermally. Silane forms covalent bonds with starch during starch modification resulted in enhanced shear strength and storage stability. A new research on biodegradable, renewable, environmentally friendly silane modification of starch-based wood adhesive that was prepared by reacting with various silanes. This paper, we reviewed silane as a modifying agent for starch-based wood adhesive.
S. K. Vineeth, Ravindra V. Gadhave, Pradeep T. Gadekar
Open Journal of Polymer Chemistry, Volume 9, pp 63-75; doi:10.4236/ojpchem.2019.94006

Abstract:Bio-based materials open a new world of possibilities in every field due to its independence from the petrochemical origin. Moreover, concerns on environmental footprints and toxicity of synthetic adhesives made scientists investigate the utilization of biomaterials for wood adhesives. In this perspective, nanocellulose as a sustainable and cheap bio-nanomaterial provides a better alternative to conventional adhesive based on formaldehyde-containing condensation resins. Property of nanocellulose to act as both binders and as structural reinforcement in various adhesive systems adds to its potential. Besides by reducing the harmful emission of formaldehyde, it also can improve the mechanical properties and enhance performance of adhesives. This review paper aims to point out the potential application of nanocellulose based wood adhesives compared to petroleum-based conventional systems beyond renewability. New functionalities through structural modification in nanocellulose could bring a replacement with the synthetic adhesive systems which will play a significant role in future bio-economy.
Ravindra V. Gadhave, Prakash A. Mahanwar, Pradeep T. Gadekar
Open Journal of Polymer Chemistry, Volume 9, pp 76-85; doi:10.4236/ojpchem.2019.94007

Abstract:The aim of this study is to analyze the various compositions of polyvinyl alcohol (PVA) and starch blends. The blends have been cross-linked with glyoxal to enhance its properties. The hydroxyl groups of PVA and starch react with glyoxal via formation of acetal bonds; hence crosslinking could take place. The cross-linking of glyoxal is observed in various analytical methods such as DSC and FTIR. The cross-linked blends showed better thermal and mechanical properties. Viscosity, tensile shear strength, pencil hardness and ultimate stress were evaluated to estimate the changes due to cross-linking. It was observed that the cross-linking is directly proportional to starch, since the starch hydroxyl groups are easily accessible for reacting. The cross-linked blend showed better cohesion between its chains, thereby increasing glass transition temperature. It was reflected in the subsequent increase in tensile strength properties.
Ravindra V. Gadhave, Shrray Srivastava, Prakash A. Mahanwar, Pradeep T. Gadekar
Open Journal of Polymer Chemistry, Volume 9, pp 27-38; doi:10.4236/ojpchem.2019.92003

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.
Fatma Ben Dhieb, Adrián Carrillo García, Seyed H. Tabatabaei, Frej Mighri, Abdellah Ajji
Open Journal of Polymer Chemistry, Volume 9, pp 100-116; doi:10.4236/ojpchem.2019.94009

Abstract:Crosslinking is a common practice to improve the barrier properties of polymers. In this study, Montmorillonite (MMT) was used with Polyvinyl alcohol (PVA) to deposit nanocomposite coatings which were crosslinked with glyoxal (Gly) by Layer by Layer (LbL) on a PET substrate. Two crosslinking conditions were studied, under mild condition and with an acidic environment. Mild condition was useful to identify the reversibility steps and the optimum crosslinking times while the acidic environment was essential to investigate the crosslinking mechanism, by determining the permeability for different crosslinking times. PVA and PVA-MMT coatings showed a strong correlation between the permeability coefficients for different crosslinking times and the FTIR results.
S. K. Vineeth, Ravindra V. Gadhave, Pradeep T. Gadekar
Open Journal of Polymer Chemistry, Volume 9, pp 86-99; doi:10.4236/ojpchem.2019.94008

Abstract:Bio-based nanomaterial is more attractive, due to its abundance, eco-friendliness and sustainability, when compared to the non-renewable toxic petrochemicals used in the wood adhesive sector. Recent studies on the formaldehyde emission by petrochemical binders in wood adhesives have attracted scientists for the research in biomaterial-based binders. In this aspect nanocellulose (NC) is one such material which has reinforcing ability and has natural binding properties. Conventional wood adhesive uses petrochemical-based binders and additives. Inclusion of nanocellulose in wood adhesive could drastically reduce the dependency on non-renewable petroleum sources. Even though wood adhesive uses NC for improving mechanical properties of the adhesive, usage is restricted because of its inability to enhance tackiness and adhesion compared with petrochemicals. Availability of free hydroxyl groups and feasibility for modification can be a potential way for functionalization of this nanomaterial. To improve adhesion properties and to make nanocellulose act as a functional filler, the crosslinking approach can be a possible solution. Enhancement of thermal properties with improved thermal degradation, water barrier properties of crosslinked films and enhanced mechanical properties especially in crosslinked poly (vinyl alcohol) (PVA) matrix, which is one of the binders for wood adhesive discussed in this review paper proves the potential applicability of crosslinked NC. Hence by inclusion of NC in wood adhesive and crosslinking with the binder, both mechanical and performance properties are expected to enhance which will create a new world and possibilities for the bio-based eco-friendly wood adhesives. In this review paper, we have reviewed the crosslinking of nanocellulose to enhance the performance of wood adhesives.
Abdumutolib Atakhanov, Islom Turdikulov, Burhon Mamadiyorov, Nodira Abdullaeva, Ilnar Nurgaliev, Yunusov Khaydar, Sayora Rashidova
Open Journal of Polymer Chemistry, Volume 9, pp 117-129; doi:10.4236/ojpchem.2019.94010

Abstract:Nanocellulose is a new class of derivatives of cellulose, which is characterized by high crystallinity, surface area, degree of dispersion, ability to decomposition by microorganisms and etc. There is high attention solving problems of obtaining nanocellulose and its application as high quality filler for polymers, biodegradable materials, additives for papers, clotting dispersion and etc. Obtaining of particles of nanosized nanostructure on the base cellulose, studying of processes of their formation, properties and creation nanotechnology on this basis give the chance to obtain materials with unique properties. In this work nanocellulose was obtained from cotton cellulose by hydrolysis with sulfuric acid, ultrasonic dispersion and microwave irradiation. The properties and structure of nanocellulose are investigated by AFM, IR-spectroscopic, X-ray methods. Nanocellulose has rod-like shape with sizes 50 - 300 nm in length and 10 - 40 nm in diameters and spherical shape with sizes 50 - 300 nm depending on the synthesis conditions of obtaining. Quantum-chemical methods have been used to calculate the electronic characteristics of nanocellulose; the change in the energy difference between HOMO and LUMO is shown, showing the change in reactivity and the manifestation of specific properties.