Polycaprolactone Polymerization processes

Typically, a low MW monomer is radically copolymerized with a (meth)acrylate funrtionalized macromonomer (MM). This method permits incorporation of macromonomers prepared by other controlled polymerization processes into a backbone prepared by a CRP. Macromonomers such as poly-ethylene, PEO, polysiloxanes, ° poly(lactic add), or polycaprolactone have been incorporated into a PS or poly (meth)acrylate backbone. This combination of controlled polymerization processes allows control of MWD, functionality. 

Pofycaprolactone (PCL) has been thoroughly examined as a biodegradable medium and as a matrix in controlled drug-release systems. PCL is predominantly produced in the e-caprolactone polymerization process [32-35]. Tokiwa and Suzuki [36] studied the hydrolysis process and PCL biodegradation by fungi and showed that polycaprolactone can be broken down enzymatically. 

Besides melt intercalation, described above, in situ intercalative polymerization of E-caprolactone (e-CL) has also been used [231] to prepare polycaprolactone (PCL)-based nanocomposites. The in situ intercalative polymerization, or monomer exfoliation, method was pioneered by Toyota Motor Company to create nylon-6/clay nanocomposites. The method involves in-reactor processing of e-CL and MMT, which has been ion-exchanged with the hydrochloride salt of aminolauric acid (12-aminodecanoic acid). Nanocomposite materials from polymers such as polystyrene, polyacrylates or methacrylates, styrene-butadiene rubber, polyester, polyurethane, and epoxy are amenable to the monomer approach. 

Table 7.1 also reports the relative FAB abimdances for the cycles contained in polycaprolactone obtained by ring-opening polymerization. Their concentration decreases in proportion to n following therefore the thermodynamic equilibration process, a result in agreement with SEC estimates. ... 

VanderHart et al. (2001a-c) studied different clay nanocomposites measuring clay exfoliation by relaxation times of hydrogen that sees iron in the montmorillonite clay. They used Fe atoms in montmorillonite clay to determine clay dispersion in Nylon-6 matrix, and degraded alkyl ammoniums (from thermal processing above 200 C) were observed by NMR technique. Hou et al. (2002,2003) studied clay intercalation of poly(styrene-ethylene oxide)-b/ocfe-copolymers using multinuclear solid-state NMR. Hrobarikova et al. (2004) prepared polycaprolactone with laponite or saponite nanocomposites by in sitn polymerization and characterized by CAP NMR to understand how surfactants at clay surface interacted with polymer matrix. Hrobarikova et al. (2004) used solid-state NMR to study intercalated species in poly(e-caprolactone)/clay nanocomposites. 

Polycaprolactone (PCL) is a biodegradable polyester that can be prepared by ring opening polymerization of s-caprolactone. Because its molecular chain has good flexibility, it has a low melting point of around 60°C and a glass transition temperature of about -60 °C, so it is often used as an additive for resins to improve their processing characteristics and impact resistance. 

PCL - The polycaprolactone is derived from 8-caprolactone by ring-opening polymerization catalyzed by transition metal compounds. Toldwa and Suzuki (Tokiwa and Suzuki, 1977) have reported that PCL can be enzymatically degraded in presence of fungi and the biodegradation process has been discussed by Bastioli (Bastioli, 1998). 

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