Converters add large quantities of plasticizers (almost 30% of weight of product) to PVC to make it flexible and durable. Phthalates are the mainstay plasticizers. Unfortunately, they migrate to the surface of the plastic over time and escape into the environment, making PVC less flexible and durable. In addition, people who come into contact with phthalates face possible health risks. The US Consumer Product Safety Commission in 2009 banned use of several phthalate plasticizers for use in manufacture of toys and child care articles, as some research has shown common phthalates to be a factor in hormone disruption in rodents and, most likely, in young children. The resulting hue and cry has resulted in partial or total ban on use of some phthalates, leading to replacement by alternative materials. Researchers believe they have developed a way to ensure phthalate plasticizers become permanently bound within any PVC part, in which they are used, with zero migration of the additives. Led by Helmut Reinecke, a research scientist at Spain’s ICTP-CSIS (Institute of Polymer Science & Technology), the team published the first report on a new way to make phthalates permanently bond to the internal structure of PVC so that they will not migrate. The laboratory tests showed that the method completely suppressed the migration of plasticizer to the surface of the plastic. The method involves covalently linking phthalate-based thiol additives, which the group developed, to the PVC molecular chain. The result was PVC only slightly less flexible than commercial PVC formulations plasticized with an equivalent amount of established phthalate plasticizer additives, but with the benefit of complete hindrance of phthalate migration. Processors could obtain similar flexibilities for both systems using a higher quantity of the covalently linked additive. The team has not yet measured the mechanical properties of its system. In order to avoid migration of plasticizers, researchers have developed a synthetic route to functionalized plasticizers with physicochemical properties similar to those of commercial DOP, but with an additional functional group able to establish a covalent bond to the polymeric backbone. The modification reaction of PVC with the novel functionalized additives was carried out in cyclohexanone solution at 60°C. DOP-SH and isoDOP-SH are suitable agents to form flexible PVC with grafted plasticizers; under the experimental conditions used these modification reactions are free of undesired side reactions like cross-linking or elimination of HCl. Plasticizers based on normal alkyd pyrrolidone, introduced for the first time for the PVC industry, have been developed by International Specialty Products (ISP) of USA. These plasticizers are called Flexidone, and are patented. They can be used as primary plasticizer or in combination with phthalate plasticizers. They are claimed to provide enhanced performance as well as processability. The addition level can be reduced by about 30-40% to achieve similar performance. It has excellent solubility and compatibility and reduces the dry blending time as well as processing temperatures. Flexidone is best used in a blend because its strong solubility with PVC will increase viscosity, even at ambient temperatures. Flexidone can deliver cold flex performance at temperatures down to - 70°C and thus provide low temperature flexibility that cannot be achieved with phthalates. In addition, the plasticizer can exhibit very low volatility and low plasticizer migration at high temperatures. Other benefits include enhanced clarity and transparency. N-alkyl pyrrolidones consist of a flexible non-polar alkyl chain with a compact hydrophilic head. The alkyl chain varies in length from C8 to C18 in the four current offerings of the series – Flexidone 100, 300, 400 and 500. Target applications include flooring, carpet backing, pond liners, roofing membranes, cable sheathing, hoses, tarpaulins, shoe soles and gaskets for refrigerators and windows. The properties of the Flexidone grades differ depending on their alkyl chain lengths. Short to mid-length chains deliver solvency, plasticizing efficiency and superior ‘cold flex’ performance. Long-length chains provide very low volatility and migration at elevated temperatures. Flexidone 300, the ‘workhorse’ of the line boasts a balance of critical performance characteristics, which makes it suitable for a broad range of applications. Flexidone 500 is targeted at specialty applications and gives superior stability and durability in hot conditions. Lanxess’ products from the Mesamoll range are alkanesulfonic acid esters that are particularly notable for their good resistance to saponification, solvating and migration properties and compatibility with a wide range of polymers such as polyvinyl chloride (PVC), rubber and polyurethane. The approvals granted for food contact applications are another advantage. Mesamoll II has been classified by the European Food Safety Authority (EFSA) as posing no risk to humans when used in food contact applications such as dry and water-based foodstuffs. This positive rating from the EFSA is the final step before European approval of the plasticizer for these areas of application, which Lanxess now expects to receive in fall 2010. Once approval is granted, Mesamoll II will be one of the few plasticizers to have received food contact approval in both the United States and the EU. Lanxess also offers further products that enable users to switch to phthalate-free additives. These include Mesamoll TP LXS 51067 and bonding agent TP LXS 51099. The new grade Mesamoll TP LXS 51067 is a fast-solvating plasticizer for PVC processing. It is particularly suitable for producing plastic floor coverings and wall coatings. The bonding agent TP LXS 51099 is a product designed for use in manufacturing PVC advertising boards, dinghies and bouncy castles/moonwalks. GRINDSTED® Soft-N-Safe, a bio-based PVC plasticizer by Danisco, contains 0% phthalates and offer: • Equivalent processing capability to DEHP • No need for major adjustments to the standard formulation in terms of plasticizing efficiency or gel-fusion temperatures unlike many products on the market • Good Low Temperature properties • Clarity and Colour Hold in clear formulations • Good Elongation at Break after Accelerated Ageing at 135°C for 7 days DOW has introduced ECOLIBRIUMTM Bio-Based Plasticizers, a new family of phthalate-free plasticizers for use in wire insulation and jacketing that are made from nearly 100% renewable feedstocks. The use of these Plasticizers in PVC compounds for wire applications can help cable-makers and original equipment manufacturers (OEMs) reduce greenhouse gas emissions by up to 40% if used instead of traditional PVC plasticizers. The new plasticizers were developed to meet growing demand for more sustainable options in wiring applications such as personal electronics and appliance wiring, residential and commercial building wiring, communications and data cabling, and automotive wiring. PVC compounds containing the two Dow bio-based plasticizers can meet all regulatory requirements for flame resistance, including the UL standard for long-term heat stability. The two new plasticizers have a molecular weight similar to plasticizers currently used in these applications. Both are very soluble in PVC, though, so processors will need to have good control of addition rates.