Styrene/methyl methacrylate impact-resistant

Transparent, Impact-Resistant, Styrene/ Methyl Methacrylate Copolymer Grafted onto Polybutadiene... 

Blends of polycarbonate with other styrenic resins are relatively new and therefore their current market volume is low. They have been developed primarily to upgrade the performance of such styrenic resins as styrenic-maleic anhydride (SMA), styrene-methyl methacrylate (S-MMA), acrylic-sty-rene-acylonitrile (ASA) resins primarily for impact strength and to some extent for DTUL improvement (Tables 15.7, 15.8 and 15.23). These blends uniquely combine high notched Izod impact strengths (ranging from 500 J/m to > 1000 J/m) with better UV resistance or weatherability than ABS. 

S-MMAIPC blend. This blend (Novacor SD-9101) was reported to have better flow, surface finish and scratch resistance than PC/polyester blends and an equivalent level of impact toughness (Table 15.24). It is believed that these formulations also include some acrylic rubber (core-shell type) for impact modification. One would expect a sufficient level of partial miscibility for self-compatibilization between the styrene-methyl methacrylate copolymer (S-MMA) and the polycarbonate especially at high MMA content of the copolymer, since the binary blends of PMMA... 

K. Nakatsuka, F. Ide, and R. Handa, Impact Resistant Resin Compositions and Method of Production Thereof, U.S. Pat. 3,502,604 (1970). Latex semi-Is and latex blends. Impact-resistant plastics. Alkyl acrylates form seed latex. Styrene, methyl methacrylate, etc. from shell. 

Properties Poly(methyl methacrylate) Cast sheet Impact- modified Heat- resistant Alkyd, molded Acrylic poly(vinyl chloride) alloy styrene-poly(vinyl chloride) alloy... 

MABS polymers (methyl methacrylate-acrylonitrile-butadiene-styrene) together with blends composed of polyphenylene ether and impact-resistant polystyrene (PPE/PS-I) also form part of the styrenic copolymer product range. Figure 2.1 provides an overview of the different classes of products and trade names. A characteristic property is their amorphous nature, i.e. high dimensional stability and largely constant mechanical properties to just below the glass transition temperature, Tg. 

A few plastics which tend to be naturally brittle require an improvement in both their drop (impact) strength and their top loading (compression) strength. In the case of polystyrene, rubber is widely used as an impact modifier. Rigid PVC, particularly when used as a container, may suffer weakness when subjected to, say, a 3 4 foot drop test. Up to 15% of methyl methacrylate butadiene styrene (MBS) copolymer is usually added to improve impact strength. Chlorinated polyethylene has more recently been introduced as a PVC impact modifier. Vinyl acetate is frequently used as a modifier for PVC film. Polythene, LDPE-HOPE can have resistance to stress (environmental stress cracking), improved by the use either of rubber or polyisobutylene. These modifications have not as yet had any pharmaceutical applications. 

Polyvinylchloride is rigid, transparent and, although it lacks the sparkle of poly styrene, is less brittle. Drop strength can be improved by the use of an impact modifier such as vinyl acetate or methyl methacrylate butadiene styrene (MBS). PVC is moderately permeable to moisture but has excellent resistance to oil and oxygen permeation. Plasticised PVC has high flexibility and is particularly useful when a collapsible pack is required. It is a poor barrier to moisture and a moderate barrier to gases, hence is usually overwrapped . 

Methyl methacrylate has been copolymerized with a wide variety of other monomers, such as acrylates, acrylonitrile, styrene, and butadiene. Copolymerization with styrene gives a material with improved melt-flow characteristics. Copolymerization with either butadiene or acrylonitrile, or blending PMMA with SBR, improves impact resistance. Butadiene-methyl methacrylate copolymer has been used in paper and board finishes. 

Poly(vinyl chloride) (PVC) homopolymer is a stiff, rather brittle plastic with a glass temperature of about 80°C. While somewhat more ductile than polystyrene homopolymer, it is still important to blend PVC with elastomer systems to improve toughness. For example, methyl methacrylate-butadiene-styrene (MBS) elastomers can impart impact resistance and also optical clarity (see Section 3.3). ABS resins (see Section 3.1.2) are also frequently employed for this purpose. Another of the more important mechanical blends of elastomeric with plastic resins is based on poly(vinyl chloride) as the plastic component, and random copolymers of butadiene and acrylonitrile (AN) as the elastomer (Matsuo, 1968). On incorporation of this elastomeric phase, PVC, which is ordinarily a stiff, brittle plastic, can be toughened greatly. A nonpolar homopolymer rubber such as polybutadiene (PB) is incompatible with the polar PVC. Indeed, electron microscopy shows... 

Acrylic resin Acrylonitrilefbutadiene/styrene copolymer Bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite Butadiene/acrylonitrile copolymer EthyleneA/A copolymer Methoxyethyl acrylate Methyl methacrylate butadiene styrene terpolymer Polyethylene elastomer, chlorinated 2-Propenoic acid, 2-methylmethyl ester, polymer with 1,3-butadiene and butyl 2-propenoate impact modifier, PVC rigid EVA/PVC graft polymer impact modifier, recycled polyamides EPDM, maleated impact modifier, thermoplastics Butadiene/acrylonitrile copolymer impact strength modifier PEG-6 trimethylolpropane impact-resistance lights Polyester carbonate resin impact-resistance, lights Polyester carbonate resin impeller... 

MABS is similar to ABS except for the addition of an additional monomer, usually methyl methacrylate. MABS is an amorphous, clear, transparent material with thermal and mechanical properties like ABS. The transparency is achieved by matching the refractive indices of the matrix resin (the transparent acrylate—acrylonitrile—styrene polymer) with the polybutadiene rubber impact modifier. MABS has the highest impact resistance of all the styrenic plastics. Sometimes called transparent... 

Multilayer butadiene-styrene- divinylbenzene-butylacrylate-methyl methacrylate Processability and high impact resistance Usami and Ochiai 1976... 

Three-component polypropylene, 1-99 wt% PP, blends comprised 1. either acidified PP, its mixture with PP, or a mixture of PP with carboxylic acid-modified EPR 2. 99-1 wt% of maleated polymer [e.g., poly(methyl methacrylate-co-styrene-co-MA] and 3. epoxy group-containing copolymer [e.g., 0.1-300 phr of ethylene-methyl methacrylate-glycidyl methacrylate = 65-15-20 or ethylene-vinyl acetate-glycidyl methacrylate = 85-5-10]. The blends were used to mold car bumpers and fenders, with good stiffness and low-temperature impact resistance ... 

Acrylics are similar to MBS and ABS but have butyl acrylate or 2-ethyl-hexyl acrylate graft phases. Acrylic modifiers are typically methyl methacrylate butylacry-late styrene or methyl methacrylate ethylhexylacrylate styrene. Acrylics offer greater resistance to UV degradation and are typically used in opaque, outdoor applications such as siding, window profiles, shutters, and gutters. Both all-acrylic and modified-acrylic impact modifiers are available. See also acrylics.)... 

---