Amino resin microcapsules are prepared from partial etherified melamine-formaldehyde resins without other additives. As model substance for the core material mainly methylparathion was used. The influences of different parameters on the encapsulation process, the capsule morphology and some capsule properties were investigated. I t is shown that by this method capsules with average diameters between 5 and 50 pn and a wall thickness between 30 and 300 nm can be obtained. The encapsulation of liquids as well as solids is possible. First ideas to the mechanisms of the capsule formation are discussed. Aminoharz-Mikrokapseln. I I . Herstellung und MorphologieAminoharz-Mikrokapseln wurden aus partiell veretherten Melamin-Formaldehyd-Harzen ohne weitere Zusatzstoffe hergestellt. Als Modellsubstanz fur das Kernmaterial wurde Methylparathion verwendet. Die Einflusse verschiedener Parameter auf den VerkapselungsprozeS, die Kapselmorphologie und einige Kapseleigenschaften wurden untersucht. Mit der beschriebenen Methode lassen sich Kapseln mit mittleren Durchmessern zwischen 5 und 50 ym und Wanddicken zwischen 30 und 300 nm herstellen. Erste Vorstellungen zum Mechanismus der Kapselbildung werden diskutiert. MuKpoKanynbk na ocnoee afiunosoLi cfionbk. I I . H3zomosnenue u fiopgfionoeuw MAKpOHaIICyJIbI H a OCHOBe aMHHOBOfi CMOJIbI H3I'OTOBJIeHbI 113 9aCTM4HO 3TepH@HIJHpOBaHHbIX MenaMHH@OpMaJIjJe-rHjT,HbIX CMOJI Be3 AO6aBOK. B Ka4eCTBe MOjJeJIbHOFO BeweCTBa AJIH HQa HCnOJIb30BaJIH MeTHJIIIapaTHOH. ~CCJIe~O-Ba.IOCb BJIHJTHHe pa3JIH4HbIX IIapaMeTpOB H a IIpO~eCC 06pa30BaHHH KaIICyJI, H a HX MOp@OJIOFHH, H HeKOTOpbIe HX CBOfiCTBa. OnHCaHHbIM MeTOAOM MOXIHO I13I'OTOBHTb KaIlCyJIbI CO CpeAHHM AHaMeTpOM 5-50 MKM H C TOJILI(HH0m CTeHKH 30-300 HM. 06CYXIRalOTCR IIepBbIe COO6paxteHHf3 OTHOCHTeJIbHO MeXaHH3Ma 06pa30BaHHJT RaIICyJI.
Amino resins can be applied as wall materials for the microencapsulation of drugs, agrochemicals, adhesives, and dyestuff systems for pressure-sensitive copying paper. The microencapsulation is carried out with unmodified or modified, etherified or non-etherified amino resins, in most cases with addition of water-soluble polymers as protective colloids. Arninoharz-Mikrokapseln. I . Literatur-und PatentiibersichtAminoharze konnen als Wandmaterial bei der Mikroverkapselung von Pharniaka, Agrochemikalien, Klebstoffen und Farbstoffsystemen fur Reaktionsdurchschreibepapiere verwendet werden. Die Mikroverkapselung erfolgt mit unmodifizierten oder modifizierten, veretherten oder unveretherten Aminoharzen, meist unter Zusatz wasserloslic her polymerer Verbindungen als Schutzkolloid.Mu%po?cancynb6 u3 aMunocMonb6. I. flumepamypHs62 u namenmimii 0630p
The surface activity of aqueous solutions of melamine formaldehyde resins was investigated at different stages of the resin synthesis. Partially methanol etherigied melamine formaldehyde resins, which are able to form microcapsules, are reactive surface active compounds. The formation of capsuole walls with these resins proved to be a one‐component interfacial polycondensation reaction.
Auf der Grundlage eines mehrparametrigen Reaktions‐Stofftransport‐Modells wurden die Geschwindigkeitskonstanten der wichtigsten chemischen Reaktionen und die Transportkoeffizienten von Ethylenglykol und Wasser bei der Polykondensation carboxylgruppenhaltiger Oligo(ethylenterephthalat)‐Schmelzen crmittelt. Der Parameteridentifizierung wurden Polykondensationsversuche in dünnen Schmelzeschichten zugrundegelegt.
Milled polybutylene terephthalate (PBT) and polytrimethylene terephthalate (PTT) were mixed with organically modified clay and extruded to prepare nanocomposites by melt intercalation. The modifier of the nanofiller belongs to the group of trialkylbenzylammonium cations. Manufacturing of the materials was carried out with a co-rotating twin-screw-extruder at 230°C and 240°C for PTT and PBT, respectively. A concentration of 3% of the inorganic filler component in the composites was aimed at. The influence of mechanical stress during extrusion on the stability of the neat polymers was tested at different speeds of rotation between 100 rpm and 800 rpm. The composites were characterized with regard to the experimental filler content and the properties of the matrix polymers like melt and crystallization temperatures, degrees of crystallinity, intrinsic viscosities, and melt viscosities. Additionally, mechanical properties were analyzed by tensile tests and discussed in term s of processing and the filler presence. The dominance of PBT as polymer matrix was highlighted
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