Terpolymers, sensitization

Inspection of Table II, Group III indicates that the terpolymer sensitivity increases with increasing oxime ester concentration, a result which parallels that for the copolymers (Group I). P(M-OM-CN) (69 16 15), the most sensitive material prepared, is 85 times more sensitive than the parent PMMA. Note that the effect on the sensitivity of incorporation of methacrylonitrile is an additive one, i.e., each terpolymer is roughly 2-3 times more sensitive than its corresponding copolymer. 

The Effect of p-t-Butylbenzoic Acid on Terpolymer Sensitivity TABLE III... 

The styrene-based terpolymers were originally used to the extent of some 2-9% in order to reduce the notch sensitivity of the polycarbonate and to improve the environmental stress cracking resistance. More recently emphasis has been on alloys with 10-50% of SAN or ABS. Alloys of polycarbonates with ASA have also become available (Luran SC-BASF)... 

An oil-based drilling mud can be viscosified with maleated ethylene-propylene elastomers [919]. The elastomers are ethylene-propylene copolymers or ethylene-propylene-diene terpolymers. The maleated elastomers are far more effective oil mud viscosifiers than the organophilic clays used. On the other hand, specific organophilic clays can provide a drilling fluid composition less sensitive to high temperatures [491]. 

Acrylamide copolymers designed to reduce undesired amide group hydrolysis, increase thermal stability, and improve solubility in saline media have been synthesized and studied for EOR applications. These polymers still tend to be shear sensitive. Acrylamide comonomers that have been used include 2-acrylamido-2-methylpropane sulfonate, abbreviated AMPS, (1,321-324), 2-sulfo-ethylmethacrylate (325,326), diacetone acrylamide (324, 326), and vinylpyrrolidinone (327,328). Acrylamide terpolymers include those with sodium acrylate and acrylamido-N-dodecyl-N-butyl sulfonate (329), with AMPS and N,N-dimethylacrylamide (330), with AMPS and N-vinylpyrrolidinone (331), and with sodium acrylate and sodium methacrylate (332). While most copolymers tested have been random copolymers, block copolymers of acrylamide and AMPS also have utility in this application (333). 

In an effort to improve PMMA s photosensitivity further, methyl methacrylate has been copolymerized with higher percentages of the a-keto-oxime methacrylate and terpolymerized with varying amounts of methacrylonitrile. The resulting effects on resist properties, e.g., sensitivity, contrast and resolution, and plasma resistance, are reported here. The terpolymers are up to 85 times more sensitive than PMMA, and retain its high resolution characteristics. 

The electron beam sensitivities of a random sample of co- and terpolymers were also determined, and were found to be essentially equal to that of PMMA. The value of 5X10 C/cm was largely invariant with oxime ester concentration, and the presence of methacrylonitrile had no effect (12). 

Block terpolymers consisting of butyl acrylate with either methylmethacrylate or methyl acrylate have been prepared where the end segments are at least 10,000 daltons and the center segment is at least 60,000 daltons. These materials were coated onto a polycarbonate surface and used to prepare an optical film and an optically clear pressure-sensitive adhesive layer that resists bubble formation when adhered to an outgassing substrate. 

Additional block terpolymers containing propyl acrylate and star block terpo-lymers containing styrene were previously prepared by the author [2] and used in hot-melt pressure-sensitive and heat-activatable adhesives. 

Random terpolymers consisting of ethyl, butyl, and behenyl acrylate were prepared by the author [3] and used as heat-activatable adhesives. Randon terpolymers consisting of iso-octyl/acrylic acid/styrene macromonomer, 92/4/ 4 mol%, respectively, were prepared by Joseph [4] and used as a reinforced pressure sensitive adhesive. 

MAA-methacryloyl chloride (MACl) reactions have been shown to form anhydride crosslinks at lower temperatures, although the starting material is more complex as it must comprise two copolymers (3-4), or a copolymer and terpolymer (5-6). Both materials make use of the greater sensitivity of the acid anhydride group but differ in the contrast mechanism involved. Roberts (3) shows that anhydride is destroyed during exposure and correlates sensitivity with anhydride content. Kitakohji et. al. (5) also associate the anhydride group with the material sensitivity but retain excess acid as a means of improving contrast. MMA-MAA and MMA-MACl copolymers have also been used separately to form crosslinked resists by reaction with a difunctional monomer (10-12). 

Lin et al. (J77) replaced PMMA with IBM terpolymer resist (a terpol-ymer of MM A, methacrylic acid, and methacrylic anhydride developed as an electron beam resist), which has a higher thermal stability and a higher DUV sensitivity. 

Giimiisderelioglu M, Topal lU (2005) Vinyl ether/acrylic acid terpolymer hydrogels synthesized by [gammaj-radiation characterization, thermosensitivity and pH-sensitivity. Radiat Phys Chem 73 272-279... 

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