Melting kinetics in polymers.

Equilibrium melting temperature and crystallization kinetics of - and -PBN crystal forms

The melting behavior and crystallization kinetics of PBN–PDEN and PBN–PTDEN copolymers were investigated using differential scanning calorimetry. Multiple endotherms were observed in all of the copolymers under investigation, originating from melting and recrystallization processes. By applying the Hoffman–Weeks method, the Tm1 of the a and b¢-PBN phases were derived. The Tm1 value of the b¢-fo...

Hmx Polymorphism: Virtual Melting Growth Mechanism, Cluster-to-cluster Nucleation Mechanism and Physically Based Kinetics

A fully physically-based thermodynamic and kinetic model of the β ↔ δ phase transformation in energetic crystal HMX crystal embedded in polymeric binder is developed. It is based on a new nucleation mechanism via melt mediated nano-cluster transformation and the recently formulated growth mechanism via internal stress-induced virtual melting. During the nucleation, nano-sized clusters of β phas...

Mini-emulsion preparation, kinetics of reaction and physical properties of acrylic terpolymer lattices

In this study, stable lattices of terpolymer butyl acrylate, methyl methacrylate, and styrene were synthesized by a mini-emulsion polymerization technique using tert-butyl hydroperoxide TBHP/Fe2 /ethylenediaminetetraacetic acid/sodium formaldehyde sulfoxylate redox initiators at room temperature, and the kinetics of the reaction were studied. The reaction rate was obtained from periodic samplin...

Experimental study of the of the thermo-regulating property of clothing system contained different melting point microencapsulated PCMs

Formulation and Evaluation of Sustained Release Ondansetron Poloxamer Based Solid Suppositories

The present investigation studies the effect of water swellable polymer hydroxylpropylmethyl cellulose (HPMC K4M, Methocel) on in vitro release of ondansetron from suppositories. Suppositories were prepared by using mixture of Poloxamer 407 and Poloxamer 188 hydrophilic bases. Suppositories containing 16 mg of ondansetron were prepared by fusion method. Weight variation, content uniformity, bre...