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Published in Eli Ruckenstein, Hangquan Li, Chong Cheng, Concentrated Emulsion Polymerization, 2019
In order to improve the properties of polymers, two or more different polymer chains are often combined. There are several ways to combine two kinds of polymer molecules: bonding the end of polymer B to the backbone of polymer A results in a graft copolymer; different chains bonded end to end generate block copolymers. If polymer A is crosslinked by polymer B and not by itself, an AB crosslinked polymer (ABCP)1–4 is obtained. In both the ABCP and in the interpenetrating polymer network (IPN), two kinds of polymer chains are combined in a network structure. The difference between the two is that in an ABCP the two kinds of chains form one single network and in an IPN they form two separate networks. Like IPN, ABCP has received attention in the past 20 years.4 However, because of crosslinking, the processability of the material prepared by bulk polymerization is poor and consequently its commercial importance has been limited. If ABCP could be prepared as latexes, it could become employed in melt-processing and find wider applications.
Micro- and Nanostructured Polymer Blends: State of the Art, Challenges, and Future Prospects
Published in Charef Harrats, Sabu Thomas, Gabriel Groeninckx, Micro- and Nanostructured Multiphase Polymer Blend Systems, 2005
Sabu Thomas, Charef Harrats, Gabriel Groeninckx
Nanostructures can also be developed by the thermal treatment of initially miscible polymer blends. The concept of forming structures by combining phase separation and crystallization is becoming increasingly more important. The crystallization, phase structure, and semicrystalline morphology of phase separated nanostructured binary blends of PEO and poly(ether sulphone) (PES) have been reported by Dreezen et al. (148). The authors have shown that 75:25 and 50:50 PEO/PES blends show a clear cocontinuous structure with a characteristic dimension of approximately 400 and 200 nm, respectively. Nanostructured full and semi-interpenetrating polymer networks have been developed from natural rubber and polystyrene by Mathew et al. (149,150). The morphology of the nanostructured system was analyzed by transmission electron microcopy after staining the natural rubber phase by osmium tetroxide. The effects of varying the initiating system, blend ratio, and cross-linking density on the morphology and properties were analyzed in detail for these interpenetrating polymer network (IPN) systems. A cocontinuous nanostructure composed of phenolic resin rich phase and PMMA rich phase was prepared by Yamazaki et al. (151) through the reaction-induced phase separation process occurring during the curing process of miscible blends of a phenolic resin and PMMA. The sample was later thermally treated to generate a carbonaceous material with continuous nanopores. The sizes of the continuous pores were from tens to hundreds of nanometers, depending on the type of the phenolic resin used.
Industrial Polymers
Published in Manas Chanda, Plastics Technology Handbook, 2017
An interpenetrating polymer network (IPN) has been defined [75,76] as “an intimate combination of two polymers both in network form, at least one of which is synthesized or cross-linked in the presence of the other.” There are no induced covalent bonds between the two polymers, i.e., monomer A reacts only with other molecules of monomer A.
Adsorptive separation of dye by filled polymeric FIPN hydrogel
Published in Indian Chemical Engineer, 2023
Samyabrata Bhattacharjee, Avijit Ghosh, Biswajit Mandal, Sunil Baran Kuila
Hydrogel, a 3-D flexible polymeric network, can exhibit diverse swelling due to different relative populations of hydrophilic groups deriving from differing quantities of additional elements, temperature and synthesis techniques [31]. Crosslinking either synthetic polymers or a mix of synthetic and natural polymers could be used to create hydrogels. In fact, artificial poly-(n) hydrogels typically have excellent mechanical strength but are not degradable [32]. Biopolymer hydrogels, on either hand, are much more degradable but lack mechanical strength [33]. By integrating the characteristics of synthetic and natural polymers, it’ll be possible to achieve an optimal balance between mechanical characteristics and bio-compatibility. In this case, an interpenetrating polymer network (IPN) type hydrogel, crafted by polymerising of one/two synthetic monomer(s) to generate a homo-/co-polymer in the presence of a natural polymer, after which crosslinking one or both polymer(s) for semi-IPN (SIPN) or full-IPN (FIPN) type network formation, can provide the required swell ability and mechanical strength. The following schematic mechanism may help to understand the process of MG like cationic dye adsorption by polymeric hydrogels.
Preparation and properties of water-responsive films with color controllable based on liquid crystal and poly(ethylene glycol) interpenetrating polymer network
Published in Liquid Crystals, 2022
Lei Zhang, Wanli He, Yongfeng Cui, Yaqian Zhang, Zhou Yang, Dong Wang, Hui Cao, Yuzhan Li
Interpenetrating polymer network (IPN) and semi-interpenetrating polymer network (SIPN) consists of two independent but interweave polymer networks, thereby combining the properties of both components, which is considered as a new strategy for the preparation of novel functional materials [20,21]. Stimuli-responsive actuators with specific functions can be obtained by constructing (IPN) or (SIPN) containing responsive groups and liquid crystals [22–24]. Stumpel et al. introduced acrylic acid as a response medium into liquid crystal polymer networks and successfully prepared polymer coatings that responded to both pH and humidity, representing the first combination of hydrogel materials and liquid crystal materials [25]. Deng et al. designed a water-responsive film containing poly(ampholyte) and studied the influence of the poly(ampholyte) content in the film on the water-responsive performance of the film [26]. Unfortunately, the influence of the liquid crystal polymer network which is another important component of the material on the properties of stimuli-responsive IPN and SIPN has not been explored.
Flurbiprofen-loaded interpenetrating polymer network beads based on alginate, polyvinyl alcohol and methylcellulose: design, characterization and in-vitro evaluation
Published in Journal of Biomaterials Science, Polymer Edition, 2020
In the recent years, interpenetrating polymer network (IPN) structures are used in a number of biomedical and biotechnological applications due to their certain biophysical properties [11]. IPN is defined as a physical mixture of two or more crosslinked polymers. If one polymer is crosslinked and the other is linear, the structure is called semi-IPN [12,13]. Also, IPN have been studied extensively in the field of drug delivery [14–17]. For instance, Rokhade et al. [15] developed semi-interpenetrating polymer network microspheres of acrylamide grafted dextran and chitosan for controlled release of acyclovir. Kajjari et al. [17] prepared semi-interpenetrating polymer network hydrogel blend microspheres of gelatin and hydroxyethyl cellulose by a water-in-oil (w/o) emulsion technique and investigated the controlled release (CR) of theophylline (THP).