Organotin polymers. VII. Copolymerization of triphenyltin methacrylate with some acrylic and methacrylic acid esters

The monomer reactivity ratios for the copolymerization of triphenyltin methacrylate with methyl acrylate, ethyl acrylate, and butyl acrylate have been found to be r₁ = 2.58, r₂ = 0.66, r₁ = 2.37, r₂ = 0.43, and r₁ = 1.27, r_0.39 = 0.39, respectively. also, the copolymerization parameters of triphenyltin methacrylate with methyl methacrylate and butyl methacrylate were as follows: r₁ = 0.94, r₂ = 0.99, and r₁ = 0.68, r₂ = 0.83, respectively. Copolymerization reactions were carried out in solution at 70°C using 1 mol % AIBN, and the copolymer compositions were determined by tin analysis. The sequence distribution of the alternating diad fractions for the systems studied were calculated at various feed compositions. The structure of the triphenyltin methacrylate monomer as well as its azeotropic copolymer with butyl methacrylate were investigated by IR spectroscopy.     

Preparation and characterization of polyelectrolyte copolymers containing methyl methacrylate and 2-hydroxyethyl methacrylate. I. Polymers based on methacrylic acid

Acidic polyelectrolyte copolymers containing 2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA), and methacrylic acid (MAA) were prepared by free radical polymerization to high conversion in solution. Copolymer yields were obtained by gravimetry (all in the 30–50% range), relative molecular weights estimated by intrinsic viscosity measurements (all in the 50–70 cc/g range), tacticity by ¹³C nuclear magnetic resonance (NMR) spectroscopy (all polymers predominantly syndiotactic with some atactic content), and composition by acid/base titrations in conjunction with ¹H-NMR spectroscopy (all close to the monomer charge ratios). Acid strengths or apparent pKa's were examined as a function of extent of ionization. Measurements performed in water indicated that the compact/extended coil transformation in predominantly syndiotactic polymethacrylic acid occurs also in copolymers of similar tacticity containing moderate to high concentrations of MAA. The apparent pKa of such polymers containing only small amounts of MAA did not vary with extent of ionization, indicating a low degree of interaction between the acid groups. In copolymer pairs containing similar amounts of MAA but differing HEMA and MMA contents, the polymer containing more HEMA appeared the stronger acid, presumably due to a better solvation of that polymer which would increase the net spatial charge–charge separation and decrease cooperative effects that lead to suppressed ionization.     

Semicontinuous emulsion polymerization of methyl methacrylate,ethyl acrylate,and methacrylic acid

By a semicontinuous emulsion polymerization method with a variable monomer feed rate, a terpolymeric latex of methyl methacrylate and ethyl acrylate functionalized with methacrylic acid was synthesized. Conversion and reactor temperature vs. time were followed during the reaction. Characterization of the latex system was performed by particle-size measurements, scanning electron microscopy, infrared spectroscopy, viscometric molecular weight, glass transition temperature measurement, and rheological behavior. © 1996 John Wiley & Sons, Inc.     

Polymer dissolution. I. On the dissolution behavior of copolymers of methyl methacrylate and methacrylic acid

Copolymers of methyl methacrylate with methacrylic acid [P(MMA/MA)] are interesting resist materials for microlithography. At moderate baking temperatures, these copolymers undergo an intramolecular cyclization, yielding terpolymers containing anhydride moieties. This process has striking consequences for the dissolution behavior and results in higher ketone solubilities. The dissolution rates in methyl ethyl ketone (MEK) and in mixtures with ethyl glycol (EG) correlate in an Arrhenius-like manner with the reciprocal baking temperatures. Two distinct temperature ranges with different slopes between 130–180°C and 180–230°C are found. This is in good agreement with other findings, indicating a different mechanism of anhydride formation in these temperature regions. The activation energies for the dissolution of P(MMA/MA) in EG or EG/MEK mixtures are about 17 kcal/mol and those of the thermally treated material in MEK or MEK/EG or mixtures of MEK with methyl isobutyl ketone (MIBK) are in the range of 20–30 kcal/mol. For the investigation of the M_n dependence, γ-irradiated probes of the copolymer were used. We obtained the usual exponential M_n dependence with an exponent of 0.7–0.8 in MIBK and 0.3–0.4 in EG. Our findings are in agreement with a “relaxation-controlled” dissolution behavior, especially for the anhydride-containing terpolymer. No residual layers or pronounced inhibition periods indicative for gel-layer formation, however, could be found. We suggest a normal dissolution process with a very small gel layer. For the copolymer in an alcohol-containing solvent, a stress-driven dissolution behaviour is more likely. © 1994 John Wiley & Sons, Inc.     

用甲基丙烯酸改善PMMA光纤芯材的耐热性

用甲基丙烯酸(MAA)改性PMMA,使其维卡软化点提高了20~23℃,透光率未降低。     

Copolymerization via zwitterion of methacrylic acid and ethyleneimine

Summary The copolymerization without initiator of methacrylic acid (MA) as nucleophilic monomer with ethyleneimine (EI) as electrophilic monomer in solution at 35°C was investigated. Copolymers are insoluble in water and in common organic solvents as CHCl₃, DMF, MeOH and they were characterized by IR spectroscopy and elemental analyses. Six copolymers were examined as resins with retention properties for copper(II), iron (III) and uranium (VI).     

Grafting of methyl methacrylate on isoprene rubber

Methyl methacrylate has been grafted on artificial isoprene rubber (IR) latex, with use of redox initiation. The properties of latices containing up to 40 phr

1 Parts per hundred parts of rubber.

methyl methacrylate (MMA) as well as solid products containing up to 80 phr of this compound were studied. Compared with ungrafted IR latex with the same solids content, the grafted IR latices had a lower viscosity, owing to their particle size being larger. Vulcanised films obtained from the grafted latices showed a considerably higher modulus, particularly at large deformations, than those based on IR or blends of IR with polymethyl methacrylate. by incorporation of certain reinforcing white fillers in the MMA-grafted IR latices, a further increase in the modulus of the latex films was effected.     

Copolymerization of aromatic polyamide macromonomers with methyl methacrylate

Summary Graft copolymers of end methacrylate-functionalized[MacroAM] or styrene-functionalized[MacroAS] polyamide macromonomers with methyl methacrylate(MMA) were prepared by radical copolymerization, and their thermal, dynamic properties, and miscibility with matrix PMMA have been investigated. The glass transition temperature(Tg)s of the copolymers were significantly elevated with the increase of the macromonomer content in the copolymer. Storage modulus E of the graft copolymers began to decrease at around 85°C, which is close to Tg of PMMA, irrespective of the macromonomer content in the copolymers. As the macromonomer content and its degree of polymerization became higher, the drop in E became significant.     

Synthesis,and NMR and thermogravimetric characterisation of block polymers of methyl methacrylate and methacrylic acid

Block polymers of methyl methacrylate and methacrylic acid have been prepared using the technique of enolate-initiated anionic polymerisation, employing trimethylsilyl methacrylate as a precursor for the methacrylic acid component. The structure of the product has been characterised by infra-red and NMR spectroscopy, and by thermogravimetric analysis.     

澳化亚铜催化下的甲基丙烯酸甲醋(MMA)与乙烯的共聚合

以溴化亚铜为催化剂,采用原子转移自由基聚合方法对MMA和乙烯进行共聚合,用核磁共振法表征了共聚物中聚乙烯的含量。结果表明,在压力为6MPa的条件下,MMA与乙烯共聚物中聚乙烯的摩尔分数可达到15.9％。关键词：甲基丙烯     

Grafting of methyl methacrylate onto sodium alginate initiated by potassium ditelluratoargentate(III)

Sodium alginate (SA) was graft‐copolymerized with methyl methacrylate in an alkali aqueous solution with potassium ditelluratoargentate(III) (DTA) as the initiator. Graft copolymers with both a high grafting efficiency (>90%) and a high percentage of grafting were obtained, which indicated that the DTA–SA redox pair was an efficient initiator for this grafting. The grafting parameters, including total conversion, grafting efficiency, and percentage grafting, were evaluated comparatively. The dependence of these parameters on temperature and time, monomer concentration, initiator concentration, and SA backbone concentration was also investigated. The overall activation energy of this grafting was calculated as 37.50 kJ/mol. Proof of grafting was obtained from gravimetric analysis and IR spectra. A tentative mechanism involving a two‐step, single‐electron‐transfer process of DTA is proposed to explain the generation of radicals and the initiation of grafting. Some basic properties of the grafted copolymer were studied by instrumental analyses, including thermogravimetry, X‐ray diffraction, and scanning electron microscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1688–1694, 2005     

Copolymerization of 2-methacryloxytropone with methyl methacrylate and ethyl acrylate

Summary 2-Methacryloxytropone was synthesized via reported methods and it's free radical initiated copolymerization with methyl methacrylate or ethyl acrylate was investigated. The 2-methacryloxytropone was found to be the more reactive monomer in both cases, however the difference in reactivity was more pronounced in the ethyl acrylate case.     

Copolymerization of methyl methacrylate and allyl acetate Part I. Rate of reaction

Free radical bulk copolymerization of methyl methacrylate (MMA) and allyl acetate (AAc) has been investigated using electron spin resonance (ESR) and FT–near infrared (FTNIR) spectroscopy. Data are used to evaluate the rate constants. The mole fraction of AAc plays an important role in the copolymerization of these two monomers. AAc not only delays the Trommsdorff effect but also increases the onset of percentage total conversion at which the Trommsdorff region begins. With AAc fraction 0.5 and higher, no Trommsdorff effect was observed. Inclusion of AAc into copolymer structure mainly occurs in the Trommsdorf region or when the AAc fraction in the comonomer feed is dominant. This is associated with a drop in the concentration of propagating radicals. However, ESR spectra indicate that the MMA propagating radical is predominant during the reaction. In the comonomer mixtures where a Trommsdorff region can be observed, the addition of AAc does not produce any significant change in k_p and k_t in the steady state region. Major changes in k_p and k_t are observed after the gel point and glassy state, respectively. © 2001 Society of Chemical Industry     

Grafting of 2-hydroxyethyl methacrylate and methyl methacrylate onto chrome tanned collagen fibers

Grafting of 2-hydroxyethyl methacrylate and methyl methacrylate onto chrome tanned collagen fibers, initiated by the bisulfite/pesulfate redox system, has been investigated. Using the method of statistical planning of experiments, regression equations have been obtained describing the effects of the monomers concentration and the composition of the initiating system on the monomers conversion, degree of grafting and on physical properties of grafted collagen. The relationship between the polyacrylate content in the composites prepared and their swelling ability, water absorption capacity, and the tensile strength is discussed.     

Preparation and characterisation of styrene—methyl methacrylate and styrene–methacrylic acid copolymer latices

Series of styrene-methyl methacrylate and styrene-methacrylic acid copolymer latices have been prepared by emulsion polymerisation using polyoxyethylene nonyl phenyl ether as emulsifier and potassium persulphate as initiator. the effects of surfactant concentration and monomer composition on the ultimate particle size and conversion were investigated. The ultimate particle diameters decreased with increasing surfactant concentration, while the conversions were found to be almost independent of surfactant concentration. The ultimate particle diameters were notably decreased by increasing the content of methacrylic acid. Trace carboxyl groups were detected both in polystyrene latex and styrene-methyl methacrylate copolymer latices. The number of sulphate groups on the polystyrene latex surface was about five times that of carboxyl groups.     

酸烯酯化合成甲基丙烯酸叔丁酯工艺研究

以甲基丙烯酸、异丁烯为原料,叔丁醇为烯烃阻聚剂,采用固定床反应器进行酸烯酯化合成甲基丙烯酸叔丁酯。探讨了酸烯投料比、反应温度、反应压力及进料空速对酸烯酯化反应的影响。结果表明,最佳反应条件为:酸烯摩尔比为3,反应温度40℃,反应压力0.5 MPa,进料空速为4 h-1。在此条件下,甲基丙烯酸转化率53.4%,异丁烯转化率80.6%,甲基丙烯酸叔丁酯选择性达96.5%。     

Copolymerization of 2,5-dimethyl-3-vinylthiophene with methyl methacrylate,styrene and isobutyl methacrylate

Summary The title vinyl thiophene monomer was synthesized by dehydration of the corresponding secondary alcohol. Free radical initiated copolymerizations with methyl methacrylate, styrene or isobutyl methacrylate were performed and the copolymer compositions were used in the calculation of reactivity ratios. The data was analyzed via a nonlinear least squares error-in-variables method. The 2,5-dimethyl-3-vinylthiophene was shown to have equal or slightly less reactivity than each of the monomers chosen as comonomers.     

Grafting of methyl methacrylate to nitrocellulose by ceric ions

Studies were carried out on grafting of various vinyl monomers to nitrocellulose by ceric ions. It was observed that graft copolymerization occurred only with methyl methacrylate (MMA) and methyl acrylate monomer. The variables such as initiator concentration, monomer concentration, time of grafting, and nitrocellulose content on grafting of MMA are discussed. By hydrolyzing away the nitrocellulose backbone, the grafted poly(methyl methacrylate) branches were isolated and the >c?o peak at 1740 cm^?1 in the infrared spectra of these isolated branches gave definite evidence of grafting. The molecular weight of isolated branches has been determined by viscometry. The probable mechanism of grafting may be at the α-carbon atom of primary alcohol or at a C₂-C₃ glycol group of the anhydro glucose unit or at the hemiacetal group of the end unit of nitrocellulose, as nitrocellulose is formed by the partial nitration of cotton cellulose.     

Copolymerization of methyl methacrylate with N-(methoxyphenyl) itaconimides

This article describes the synthesis and characterization of N-(3-methoxyphenyl) itaconimide (MAI) and N-(4-methoxyphenyl) itaconimide (PAI) obtained by the reaction of itaconic anhydride with m-anisidine and p-anisidine, respectively. Structural and thermal characterization of MAI and PAI monomers was performed with Fourier transform infrared (FTIR), ¹H-NMR, differential scanning calorimetry (DSC), and thermogravimetric analysis. Copolymerization of methyl methacrylate (MMA) with various amounts of MAI or PAI ranging from 0.1 to 0.5 was performed in solution with azobisisobutyronitrile as an initiator. Structural and molecular characterization of copolymers was performed with FTIR, ¹H-NMR, elemental analysis, and gel permeation chromatography. The nitrogen percentage was used to calculate the copolymer composition. The monomer reactivity ratios for MMA–MAI copolymers were found to be 1.00 ± 0.01 for MMA and 0.99 ± 0.07 for MAI; those for MMA–PAI copolymers were 0.93 ± 0.02 for MMA and 1.11 ± 0.10 for PAI. The molecular weights of the copolymers were in the range of 0.94–9.7 × 10³ (number-average molecular weight) and 3.3–101.8 × 10³ (weight-average molecular weight), with polydispersity indices in the range of 1.5–4.1. The molecular weight decreased with the increasing molar fraction of imide in the polymer backbone. The glass-transition temperature, as determined from DSC scans, increased with increasing amounts of itaconimides in the copolymers. A significant improvement in the char yield, as determined by thermogravimetry, was observed upon copolymerization. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008