Butyl methacrylate, BuMA

Controlled anionic polymerization of alkyl methacrylates initiated by 1,1-diphenyUiexyllithium using a flow microreactor gives the corresponding poly (aUcyl methacrylate)s with high level of control of molecular weight under easily accessible temperatures compared with conventional batch macropolymerization, e.g., —28°C for methyl methacrylate (MMA) (MJMn = 1.16), 0°C for butyl methacrylate (BuMA) MJM = 1.24), and 24°C for tert-butyl methacrylate (f-BuMA) (Mw/Mn = 1.12). Precise control of the reaction temperature and fast mixing of a monomer and an initiator seem to be responsible (Fig. 16) [161]. 

MMA), butyl methacrylate (BuMA)) (Figure 4.12) was polymerized with a PLA or PDMS macromonomer. The second strategy was a two-step approach in which a graft copolymer containing one macromonomer was polymerized with PLA macromonomer (Figure 4.12) [83]. 

Bone cements are, traditionally, injectable systems based on acrylic polymers. They are constituted by a solid and a liquid component that harden after mixing due to the polymerization of acrylic monomers in the liquid. Just some minutes after mixing, the paste attains high viscosity and must then be injected into the bone cavity, where the final stages of polymerization will take place. The solid is in most cases constituted by poly(methyl methacrylate) (PMMA) powder (or a copolymer of MMA with others monomers), benzoyl peroxide (BPO, the initiator of the polymerization), and a radio-opacifier, while the liquid is formed by MMA monomer (in some cases with n-butyl methacrylate, BuMA) and dimethyl-j -toluidine (DMT, the activator of the initiator). 

Abbreviations y x AFM AIBN BuMA Ca DCP DMA DMS DSC EGDMA EMA EPDM FT-IR HDPE HTV IPN LDPE LLDPE MA MAA MDI MMA PA PAC PB PBT PBuMA PDMS PDMS-NH2 interfacial tension viscosity ratio atomic force microscopy 2,2 -azobis(isobutyronitrile) butyl methacrylate capillary number dicumyl peroxide dynamic mechanical analysis dynamic mechanical spectroscopy differential scanning calorimetry ethylene glycol dimethacrylate ethyl methacrylate ethylene-propylene-diene rubber Fourier transform-infra-red high density polyethylene high temperature vulcanization interpenetrating polymer network low density polyethylene linear low density polyethylene maleic anhydride methacrylic acid 4,4 -diphenylmethanediisocyanate methyl methacrylate poly( amide) poly( acrylate) poly(butadiene) poly(butylene terephtalate) poly(butyl methacrylate) poly(dimethylsiloxane) amino-terminated poly(dimethylsiloxane)... 

IPNs are also attractive for development of materials with enhanced mechanical properties. As PDMS acts as an elastomer, it is of interest to have a thermoplastic second network such as PMMA or polystyrene. Crosslinked PDMS have poor mechanical properties and need to be reinforced with silica. In the IPNs field, they can advantageously be replaced by a second thermoplastic network. On the other hand, if the thermoplastic network is the major component, the PDMS network can confer a partially elastomeric character to the resulting material. Huang et al. [92] studied some sequential IPNs of PDMS and polymethacrylate and varied the ester functionalities the polysiloxane network was swollen with MMA (methyl methacrylate), EMA (ethyl methacrylate) or BuMA (butyl methacrylate). Using DMA the authors determined that the more sterically hindered the substituent, the broader the damping zone of the IPN (Table 2). This damping zone broadness was also found to be dependant on the PDMS content, and atomic force microscopy (AFM) was used to observe the co-continuity of the IPN. 

AA acac alt AIBN Ar Bd Bu BuA BuMA BzMA CMSty CR CT CTFE DBP DPn EA HEA HEMA HFP acrylamide acetylacetonate alternating azobisisobutyronitrile aromatic group butadiene n-butyl n-butyl acrylate n-butyl methacrylate benzyl methacrylate chloromethyl styrene counter-radical transfer constant chlorotrifluoroethylene dibenzoyl peroxide average degree of polymerization in number ethyl acrylate 2-hydroxyethyl acrylate 2-hydroxyethyl methacrylate hexafluoropropene... 

An attempt to investigate quantitatively the ageing of PS and poly-tert-butyl methacrylate (P-i-BuMA) has been taken by Huber [11]. The researeh was performed in a flow system of air containing 60-900 ppm of NO2 and/or 60-900 ppm SO2 at 300 K under the simultaneous action of light with X > 290 run. The degradation of P-i-BuMA films was expressed in terms of the quantity of ruptures per 10,000 monomer units, a. The kinetic dependence is represented by the equation ... 

Several s -copolymers of MMA and alkyl methacrylates with narrow MWD were also prepared with -C4HgLi-(n-C4Hg)3Al. Glass transition temperatures for the sL-copolymers of MMA and butyl methacrylate (n-BuMA) are shown in Figure 6. Recently, block and random s -copolymers of MMA and benzyl methacrylate as well as s -poly(benzyl methacrylate) prepared with -C4HgLi-R3Al were found to form stereocomplex with i -PMMA in solid and in solution [16]. 

Alkyl methacrylates Alkyl= Methyl (MMA) n-butyl, t-butyl (BuMA) Octyl Lauryl Octadecyl Phenyl Dimethylaminoethyl... 

Other methacrylates snch as ethyl methacrylate (EtMA), isobomyl methacrylate (/-BMA) and t-bntyl methacrylate (t-BnMA) were successfully polymerised at 35 °C as well (Table 1). For PEtMA and Pt-BuMA, very low polydispersities of 1.15 and 1.14 were obtained. For polymerisations of isobomyl methacrylate, on the other hand, a significantly broader molecular weight distribution of PDI = 2.46 was fonnd. The two acrylates tested, -butyl acrylate ( -BnA) and t-bntyl acrylate (t-BuA), gave very low conversions (Table... 

Table 3). In case of polymerization of ethyl (EM A) and -butyl ( -BuMA) methacrylates under the same conditions, a bimodal molecular mass distribution was observed. The similar isotacticity in both fractions, indicates the existence of two types of active species [169]. The addition of (CH3)3A1 to the polymerization of EMA recently has been found to have the beneficial effect of allowing the synthesis of highly isotactic PEMA with low polydispersity [167]. 

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