pH‐sensitive beads were prepared from the interpenetrating polymer networks (IPNs) of carboxymethyl chitosan (CMCTS) and alginate to study their application in oral insulin administration. CMCTS was synthesized from chitosan and was characterized by Fourier transform infrared spectroscopy and wide‐angle X‐ray diffraction. Calcium chloride, a relatively less toxic material, was used to crosslink both the alginate and CMCTS to prepare the IPN beads. The IPN beads were used to encapsulate insulin at different weight ratios. The swelling behavior and insulin release profile in response to simulated gastric and intestinal media of the beads were investigated. The beads observed under scanning electron microscopy were almost spherical, with an average diameter of 780 μm. The bead with about a 54% insulin loading efficiency was observed to contain about 98% encapsulated insulin. The maxima of about 20% insulin retention at acidic pH (1.2) and about 94% insulin release at intestinal pH (7.4) justified the good pH‐responsive nature of these IPN beads. Moreover, the insulin released from the IPN beads was stable and biologically active. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

The degradation of polyethylene terephthalate (PET) waste by making use of hydrazine monohydrate was investigated at ambient temperature and pressure. The aminolysed end products obtained were characterized with chemical tests and spectroscopic techniques namely IR, UV-visible spectroscopy and NMR, and the differential scanning calorimeter (DSC). The end product was characterized as terephthalic dihydrazide (TPD) and further used in PVC compounding as secondary plasticizer. The hardness, tensile strength, elongation at break, thermal stability, and compatibility of the PVC sheet were studied and concluded that the aminolysed product may find potential application as secondary plasticizer in PVC formulations.

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